United States v. Franck's Lab, Inc. (816 F. Supp. 2d 1209, 2011)

ORDER

TIMOTHY J. CORRIGAN, District Judge.

In the seventy-plus years since Congress created the Food and Drug Administration, the FDA has never before sought to enjoin a state-licensed pharmacist from engaging in the traditional practice of bulk compounding of animal drugs. Here, the FDA seeks just such an injunction. This case of first impression implicates matters of statutory construction, federalism, and the proper deference to be afforded to the FDA in interpreting its enabling statute.

I. Facts and Procedural Posture

This statutory injunction proceeding is brought by the United States of America, on behalf of the FDA, against defendants Franck’s Lab, Inc. d/b/a Franck’s Compounding Lab (“Franck’s”) and Paul W. Franck, Franck’s owner and CEO. Franck’s is a pharmacy located in Ocala, Florida which compounds and distributes a wide variety of drugs for both humans and animals to customers across the United States.

The facts of this case are straightforward and largely undisputed. Mr. Franck, a Florida-licensed pharmacist in good standing since 1981, opened an independent pharmacy practice in Archer, Florida in 1983. Over the next several years, Franck expanded his practice by purchasing or opening additional retail pharmacies, including a location in Ocala in 1985. That same year, Franck began to compound medications at the Ocala location for humans and “non food-producing animals” (such as horses). The Ocala pharmacy was later expanded into two practices which now comprise Franck’s: Franck’s Lab, which operates as a compounding pharmacy, and Franck’s Pharmacy, which is a traditional retail pharmacy. At the time the FDA instituted this action, Franck’s employed approximately 65 individuals full-time.

Animal and veterinary drug compounding comprises roughly 40 percent of Franck’s Lab’s business, while human drug compounding accounts for the remaining 60 percent. Franck’s compounds the majority of its animal medications from “bulk” active ingredients, which it receives from suppliers outside the state of Florida. The company also receives prescription orders from customers outside Florida and ships its compounded products to those out-of-state customers. Franck’s holds a valid pharmacy license in each of the 47 states in which it is required to do so, and, nationwide, fills approximately 37,-000 animal drug prescriptions per year.

The FDA first inspected Franck’s compounding facilities between September 29 and October 4, 2004 and, in January 2005, issued a warning letter expressing concern that Franck’s was impermissibly manufacturing drugs. (Doc. 17-1, Declaration of Emma Singleton (“Singleton Dec.”), Ex. E.) Among the FDA’s concerns were: (i) Franck’s practice of compounding veterinary drugs using bulk active pharmaceutical ingredients; (ii) that a number of those drugs “appear[ed] to be compounded outside the context of a valid veterinarian-client-patient relationship;” and (iii) that Franck’s was compounding drugs where an approved drug would adequately treat the animal. (Id. at 1-2.)

Franck’s responded by letter dated January 27, 2005, asserting its intention to be in full compliance with all FDA requirements. (Id. Ex. F.) However, Franck’s also expressed disagreement with the FDA’s position that bulk compounding of animal drugs was per se unlawful and noted that “[sjtate law and good compounding practices ... allow bulk compounding as long as there is a valid patient physician (veterinarian) relationship.” (Id. at 1.) Franck’s further argued that, because “the FDA allows compounding by bulk chemicals for human use, ... the same should apply to veterinary compounding.” (Id.) Despite the disagreement, Franck’s pledged: (1) to dispense compounded veterinary drugs only to licensed veterinarians pursuant to a “valid patient-veterinarian relationship”; (2)'to compound from bulk only those drugs that were commercially unavailable; and (3) to place warning labels on its products to make clear that its compounds were “not to be used on food producing animals.” (Id. at 1-2.) In closing, Franck’s stated:

Again, it is Franck’s intention to comply immediately and completely with any and all FDA and other legal requirements, and welcomes [sic] the FDA’s involvement in these matters. I have tried to the best of my ability to address each item of concern in your letter. If I have fallen short on anything, if you have additional concerns which were not set forth in your letter, or if you have any other questions or concerns, please contact me immediately and I will see to it that we respond immediately, and to your complete satisfaction.

(Id. at 2.) FDA did not respond to Franck’s’ letter and did not take any further action against the pharmacy at that time.

In April 2009, a veterinarian commissioned Franck’s to compound an injectable solution of the prescription drug Biodyl for the Venezuelan national polo team. Due to a mathematical error in the conversion of an ingredient (which went unnoticed by the prescribing veterinarian), the compounded medication was too potent and 21 polo horses died. The incident was thoroughly investigated by the Florida Board of Pharmacy, which imposed fines and reprimanded Franck’s for the misfilled prescription. Despite the reprimand, the Board voted to allow Franck’s to continue its pharmacy compounding practice without restriction, and Franck’s remains in good standing in Florida. The FDA has acknowledged that it was a mathematical error, as opposed to “faulty bulk drugs,” which caused the death of the polo ponies. (Doc. 47 at 27.)

Though the Florida Board of Pharmacy had investigated and resolved the matter to its satisfaction, the Venezuelan polo pony incident prompted the FDA to reinspect Franck’s facilities three times: May 4-20, 2009; June 18-23, 2009; and December 1-4, 2009. Subsequent to the May inspection, the FDA issued Franck’s a Form FDA 483 which contained five specific observations, none of which identified bulk compounding of animal drugs as a concern. (Singleton Dec. Ex. B.)

Franck’s responded to the Form 483 by letter dated June 12, 2009. (Id. Ex. C.) The letter stated that the pharmacy had “carefully considered the [FDA’s] observations” and used them “to help further strengthen our operations.” (Id. at 1.) However, Franck’s noted that:

the observations that FDA has outlined involve pharmacy practices that we must strenuously assert are regulated by the Florida Department of Health and Board of Pharmacy. We are concerned that FDA is attempting to assert authority over Franck’s Pharmacy that it reserves for drug manufacturers. Put simply, we are a compounding pharmacy that fills prescriptions to meet the needs of individual patients; we are not a drug manufacturer....

The events that are the subject of the FD-483 observations [i.e., the polo pony incident] represent classic, traditional compounding. Franck’s was filling a single prescription from a veterinarian specifically and solely for that veterinarian’s patients. This was prototypical compounding ....

The Florida Department of Health [conducted] its own inspection and [viewed] the incident as one relating to compounding. Even the FDA investigators orally acknowledged that the activities in question constituted compounding Franck’s has been compounding human and veterinary drugs for more than 25 years to meet the special needs of doctors, veterinarians, and patients. We take both our obligations to our patients and our regulatory responsibilities very seriously.

(Id. at 2-4.) Without further' response or discussion, FDA initiated this action in April of 2010, seeking to enjoin Franck’s practice of distributing animal drugs compounded from bulk substances.

After Franck’s moved to dismiss the complaint (Doc. 13), the FDA sought a preliminary injunction (Doc. 16). The Court heard oral argument on August 18, 2010 (Doc. 43), the record of which is incorporated by reference. The Court subsequently denied both motions (Doc. 44) and, at the parties’ request, postured the case for resolution via dispositive motions (Doc. 53). The parties then fully developed the record, each submitting declarations and other materials, as well as a Joint Stipulation of Undisputed Facts (Doc. 55). Thereafter, the parties filed extensive cross-motions for summary judgment and responses thereto (Docs. 54, 56, 59, 60). The Court heard lengthy oral argument on the parties’ cross-motions on February 24, 2011 (Doc. 61), the record of which is incorporated by reference.

II. The Record Allows for Disposition on Cross-Motions for Summary Judgment

The FDA acknowledges that this is the first time it has sought to enjoin a state-licensed pharmacist from bulk compounding of animal medications. Further, through its development of the record and posturing of this ease, the FDA has made clear that the legal violation it asserts is not contingent on any fact-specific grounds unique to Franck’s. Rather, the FDA has taken the bright-line position that any compounding of animal medications from bulk substances violates its enabling statute, the Federal Food, Drug, and Cosmetic Act, 21 U.S.C. § 301, et seq. (“FDCA”), even when conducted by a state-licensed pharmacist for an individual animal patient pursuant to a valid veterinary prescription. Franck’s admits that it routinely engages in this practice, but contends that it does not violate the FDCA.

The FDA’s evidentiary support for this action is primarily contained in two declarations that describe: (i) Franck’s alleged violative history (as set forth infra, see Singleton Dec.); and (ii) the FDA’s rationale and asserted authority for regulating animal drug compounding, (see Doc. 17-2, Declaration of Dr. William Flynn (“Flynn Dec.”)). In response, Franck’s submitted a number of declarations from veterinarians, pharmacists, and other expert and fact witnesses relating to, inter alia: (i) the FDA’s historical acceptance of and shifting approach towards “traditional pharmacy compounding”; (ii) their understanding of the FDA’s role in regulating the practice; (iii) the necessity of bulk compounding to provide life-saving treatment for non food-producing animal patients; (iv) the ubiquity of the practice of compounding animal drugs from bulk; and (v) the industry standards for quality control in the preparation of such compounded medications. (See Doc. 28, Declaration of Paul W. Franck (“Franck Dec.”); Doc. 29, Declaration of Gigi S. Davidson (“Davidson Dec.”); Doc. 30, Declaration of Dr. Loyd V. Allen (“Allen Dec.”); Powers Dec.; Doc. 32, Declaration of Kevin Stoothoff, D.V.M. (“Stoothoff Dec.”); Doc. 33, Declaration of Rick Pelphrey, D.V.M. (“Pelphrey Dec.”); Doc. 35, Declaration of Sheldon T. Bradshaw (“Bradshaw Dec.”).)

Though the FDA had ample opportunity to dispute these assertions, it chose not to do so, resting instead on its position that compounding animal drugs from bulk— which Franck’s admits it does — constitutes a per se violation of the FDCA. As a result, the statements contained in Franck’s’ declarations are largely uncontroverted in the record, and where appropriate, the Court treats them as such.

Because no material facts are in dispute, the parties’ cross-motions present this Court with a pure question of law. “When the only question a court must decide is a question of law, summary judgment may be granted.” Saregama India Ltd. v. Mosley, 635 F.3d 1284, 1290 (11th Cir.2011) (citing Cook ex rel. Estate of Tessier v. Sheriff of Monroe Cnty., 402 F.3d 1092, 1120 (11th Cir.2005)) (“A summary judgment should not be granted unless the facts are so crystallized that nothing remains but questions of law”). “The principles governing summary judgment do not change when the parties file cross-motions for summary judgment. When faced with cross-motions, the Court must determine whether either of the parties deserves judgment as a matter of law on the undisputed facts.” T-Mobile South LLC v. City of Jacksonville, Florida, 564 F.Supp.2d 1337, 1340 (M.D.Fla.2008).

III. Background

A. Compounding and Compounding from Bulk Substances

Compounding is a process by which a pharmacist combines, mixes, or alters ingredients to create a medication tailored to the needs of an individual human or animal patient. Thompson v. W. States Med. Ctr., 535 U.S. 357, 360-61, 122 S.Ct. 1497, 152 L.Ed.2d 563 (2002); Med. Ctr. Pharm. v. Mukasey, 536 F.3d 383, 387 (5th Cir. 2008). Compounding is “a traditional component of the practice of pharmacy, and is taught as part of the standard curriculum at most pharmacy schools.” W. States, 535 U.S. at 361, 122 S.Ct. 1497 (internal citations omitted). Because the practice of pharmacy is state-governed, the States, including Florida, regulate compounding as part of their regulation of pharmacists. Id.

Under Florida law, pharmacists may compound medications when they are prescribed for individual patients by a licensed medical practitioner (i.e., a veterinarian), or in anticipation of prescriptions based on routine, regularly observed prescribing patterns. This “triad” relationship among veterinarian, patient, and pharmacist envisions a compounding pharmacist working eollaboratively with a veterinarian to provide a medication tailored to an animal patient’s specific and individualized needs. (See Davidson Dec. ¶ 36.) The pharmacist-prescriber-patient relationship forms the basis of what is commonly known as “traditional pharmacy compounding.”

“Compounding is typically used to prepare medications that are not commercially available, such as medication for a patient who is allergic to an ingredient in a mass-produced product.” W. States, 535 U.S. at 361, 122 S.Ct. 1497. When a drug is not commercially available, or the commercially available drug is unsuitable for a particular patient, compounding is often the only way for a human or animal patient to obtain necessary medication for the safe and effective treatment of their condition. See id. at 369, 122 S.Ct. 1497. This is especially so for non food-producing animals because limited commercially available products exist and the available products are often inadequate due to the animal patient’s size, species, and/or intolerance to active ingredients. (Davidson Dec. ¶ 35); cf. U.S. v. 9/1 Kg. Containers, More or Less, of an Article of Drug for Veterinary Use, 854 F.2d 173, 174 (7th Cir.1988) (“We must take it as given that for significant [animal] diseases there are no effective FDA-approved drugs.... For the principal diseases of non-food animals ... there are few, if any, approved remedies”).

A pharmacist can compound a medication requested by the prescribing veterinarian from either a finished drug product or from bulk drug substances. (Flynn Dec. ¶ 15.) Between the two, compounding from bulk substances has become the “widely preferred” method among veterinarians due to “concerns about the quality, safety, and efficacy of animal medications compounded from finished products.” (Allen Dec. ¶¶ 17, 24.) Pharmacists also favor compounding from bulk because use of bulk ingredients ensures that the compounded medicine is of the expected purity, potency, and quality; further, it is often not practical or possible to compound a medically necessary animal drug from an FDA-approved finished drug product. (Id. ¶¶ 17, 23-25.) In addition, the standards for potency and purity of compounded medications required by the United States Pharmacopeia (“USP”), which the original FDCA recognized as its “official compendium,” Food, Drug and Cosmetic Act of 1938, Pub.L. No. 75-717, 52 Stat. 1040 (“1938 FDCA”) § 201(j), are more readily obtained using bulk ingredients. (Allen Dec. ¶¶ 27-32.) As a result, compounding from a finished drug product “is more likely to result in a compounded preparation outside of the [USP’s] required potency and purity specifications than compounding from a bulk ingredient.” (Id. ¶ 29.)

Under Florida law, traditional compounding from bulk substances is an approved part of the practice of pharmacy. As a result, many, if not all, compounding pharmacies in Florida compound drug products from bulk ingredients. (Powers Dec. ¶ 24.) Florida is not an outlier in this regard; the practice of compounding from bulk ingredients is expressly recognized by many states and is a “widespread practice performed by the majority of licensed compounding pharmacy professionals throughout the country, and has been for decades.” (Allen Dec. ¶ 23.)

B. The FDA’s Regulation of Compounding

1. From 1938 to 1992

The history of the FDA’s regulation of pharmacy compounding has been reviewed several times, most notably by the Supreme Court in Western States, 535 U.S. at 360-66, 122 S.Ct. 1497, and the Fifth Circuit in Medical Center, 536 F.3d at 387-91. As the Supreme Court recounted (emphasis and footnotes added):

The Federal Food, Drug, and Cosmetic Act of 1938 (FDCA), 21 U.S.C. §§ 301-397, regulates drug manufacturing, marketing, and distribution. Section 505(a) of the FDCA provides that “[n]o person shall introduce or deliver for introduction into interstate commerce any new drug, unless an approval of an application filed [with the Food and Drug Administration] is effective with respect to such drug.” 21 U.S.C. § 355(a). “[N]ew drug” is defined by § 201(p)(l) of the FDCA, 52 Stat. 1041, as amended, 76 Stat. 781, as “[a]ny drug ... not generally recognized, among experts qualified by scientific training and experience to evaluate the safety and effectiveness of drugs, as safe and effective for use under the conditions prescribed, recommended, or suggested in the labeling thereof.” 21 U.S.C. § 321(p). The FDCA invests the Food and Drug Administration (FDA) with the power to enforce its requirements. § 371(a).

For approximately the first 50 years after the enactment of the FDCA the FDA generally left regulation of compounding to the States. Pharmacists continued to provide patients with compounded drugs without applying for FDA approval of those drugs. The FDA eventually became concerned, however, that some pharmacists were manufacturing and selling drugs under the guise of compounding, thereby avoiding the FDCA’s new drug requirements. In 1992, in response to this concern, the FDA issued a Compliance Policy Guide, which announced that the “FDA may, in the exercise of its enforcement discretion, initiate federal enforcement actions ... when the scope and nature of a pharmacy’s activities raises the kinds of concerns normally associated with a manufacturer and ... results in significant violations of the new drug, adulteration, or misbranding provisions of the Act. ” Compliance Policy Guide 7132.16 (hereinafter [1992] Guide). The Guide explained that the “FDA recognizes that pharmacists traditionally have extemporaneously compounded and manipulated reasonable quantities of drugs upon receipt of a valid prescription for an individually identified patient from a licensed practitioner,” and that such activity was not the subject of the Guide. The Guide said, however, “that while retail pharmacies ... are exempted from certain requirements of the [FDCA], they are not the subject of any general exemption from the new drug, adulteration, or misbranding provisions” of the FDCA. It stated that the “FDA believes that an increasing number of establishments with retail pharmacy licenses are engaged in manufacturing, distributing, and promoting unapproved new drugs for human use in a manner that is clearly outside the bounds of traditional pharmacy practice and that constitute violations of the [FDCA].” The Guide expressed concern that drug products “manufactured and distributed in commercial amounts without [the] FDA’s prior approval” could harm the public health.

In light of these considerations, the Guide announced that it was FDA policy to permit pharmacists to compound drugs after receipt of a valid prescription for an individual patient or to compound drugs in “very limited quantities” before receipt of a valid prescription if they could document a history of receiving valid prescriptions “generated solely within an established professional practitioner-patient-pharmacy relationship” and if they maintained the prescription on file as required by state law. Compounding in such circumstances was permitted as long as the pharmacy’s activities did not raise “the kinds of concerns normally associated with a manufacturer.”

W. States, 535 U.S. at 361-63, 122 S.Ct. 1497 (emphasis added and citations omitted).

After acknowledging that the FDA would “generally continue to defer to state and local offieialsF] regulation of the day-to-day practice of retail pharmacy and related activities,” the 1992 Guide listed nine non-inclusive activities that the FDA believed would improperly cross the line between “pharmacist” and “manufacturer” and thus would prompt the FDA to “initiate federal enforcement actions” in the “exercise of its enforcement discretion.” 1992 Guide at 4-5. The practice of compounding drugs from bulk substances was not among the nine prohibited practices, though the concern that large-scale compounding from bulk might be indicative of manufacturing was mentioned elsewhere in the 1992 Guide.

& AMDUCA

In 1994, Congress passed the Animal Medicinal Drug Use Clarification Act (“AMDUCA”), which amended the FDCA to permit certain off-label uses of FDA-approved human and animal drugs in the treatment of animals. 21 U.S.C. §§ 360b(a)(4) and (a)(5). Under AMDUCA, the off-label or extra-label use of an already approved new animal or new human drug prescribed by a licensed veterinarian in the context of a valid pharmacistpreseriber-patient relationship does not require approval under the FDCA’s “new animal drug” provisions, and thus does not cause the drug to become “adulterated.” Id. AMDUCA authorized the FDA to promulgate regulations which “establish the conditions” for such off-label use. Id. §§ 360b(a)(4)(A), 5(B).

Though Congress made no mention of either compounding or bulk drugs in AMDUCA, the FDA regulations promulgated to implement AMDUCA explicitly reference both. Section 530.13, entitled “Ex-tralabel use from compounding of approved new animal and approved human drugs,” provides that “[t]his part applies to compounding of a product from approved animal or human drugs by a veterinarian or a pharmacist on the order of a veterinarian within the practice of veterinary medicine. Nothing in this■ part shall be construed as permitting compounding from bulk drugs.” 21 C.F.R. § 530.13(a) (emphasis added).' Despite this language, the regulations do not purport to regulate the practice of compounding, and instead refer parties to FDA’s non-binding guidance documents on the subject. See id. § 530.13(c) (“Guidance on the subject of compounding may be found in guidance documents issued by FDA”).

3. The 1996 Guide

In 1996, the FDA published notice in the Federal Register inviting public comment on a Compliance Policy Guide outlining the agency’s non-binding “policy and regulatory guidelines” with respect to the compounding of animal drugs by veterinarians and pharmacists. 61 Fed.Reg. 34,849, 34,-849 (1996) (“1996 Guide”). The 1996 Guide noted that the FDCA “does not distinguish compounding from manufacturing or other processing of drugs for use in animals,” nor does it exempt pharmacists and veterinarians from the FDCA’s new drug approval provisions. Id. at 34,850. While the .FDA “acknowlege[d] the use of compounding within certain areas of veterinary practice,” it also asserted that “compounding allowed under the [FDCA] is limited to the preparation of drug products which do not meet the definition of new animal drugs” and that “[i]n the absence of an approved new animal drug application (NADA), the compounding of a new animal drug from ... a bulk drug, results in an adulterated new animal drug....” Id

Despite this broad assertion of the FDA’s authority, the 1996 Guide recognized a legitimate place for compounding. Specifically, the Guide provided that “compounding by a licensed pharmacist or veterinary practitioner, when the criteria described in this document are met, [and] within the confines of a legitimate practice” would constitute “compounding ordinarily not subject to regulatory action.” Id. With this background, the 1996 Guide’s “Policy” section began with the acknowledgment that “[c]ircumstances exist when it may be necessary for a veterinarian to compound, or direct for a pharmacist to compound, an article that will result in an unapproved animal drug.” Id. at 34,851. In such circumstances, the FDA recognized that there was “occasionally a need to utilize ... bulk drug substances[ ] for compounding into an appropriate dosage form.” Id. The FDA would thus condone compounding animal drugs from bulk where: (1) a “legitimate medical need [wa]s identified”; (2) there was an “appropriate dosage regimen” for the patient’s species, age, size, or medical condition; and (3) there was “no marketed approved animal drug” that “may treat the condition diagnosed in the available dosage form.” Id. Under these conditions, the FDA would ordinarily not exercise its enforcement authority against a compounding pharmacist so long as the medication was dispensed within the confines of a pharmacist-prescriber-patient relationship; the drug was adequately labeled to ensure proper use; and the pharmacist adhered to the National Association of Boards of Pharmacy Good Compounding Practices, or to equivalent state good compounding regulations. Id. The FDA closed its policy pronouncement with the following: “Veterinarians and pharmacists who compound or prescribe compounded medicaments and pharmacists who compound medicaments according to these guidelines criteria set out above would be considered to be engaged in extemporaneous compounding not ordinarily subject to regulatory action.” Id.

The 1996 Guide then listed thirteen situations which would “likely indicate compounding subject to regulatory action.” Id. “Compounding from bulk drugs for use in food animals,” with certain limited exceptions, was among the listed scenarios. Id. (emphasis added). However, “[c]om-pounding from bulk drug substances - for use in nonfood animals” was expressly identified as a “compounding situation [which] would not ordinarily be considered for regulatory action.” Id. at 34,852.

A FDAMA & Western States

In 1997, “in a move the Pharmacies call a reaction to the FDA’s 1992 [Guide] and the FDA characterizes as a confirmation of it, Congress amended the FDCA by enacting the Food And Drug Modernization Act of 1997 (“FDAMA”), Pub.L. No. 105-115, 111 Stat. 2296 (codified as amended at 21 U.S.C. § 353a (2000)).” Med. Ctr., 536 F.3d at 391. Expressly addressing “pharmacy compounding,” FDAMA, which applies only to human drugs, provides that the FDCA’s new drug approval, adulteration, and misbranding provisions “shall not apply to a drug product if the drug product is compounded” pursuant to certain guidelines. 21 U.S.C. § 353a(a) (emphasis added). As summarized by the Supreme Court in Western States, those guidelines are as follows:

First, [compounded drugs] must be compounded by a licensed pharmacist or physician in response to a valid prescription for an identified individual patient, or, if prepared before the receipt of such a prescription, they must be made only in “limited quantities” and in response to a history of the licensed pharmacist’s or physician’s receipt of valid prescription orders for that drug product within an established relationship between the pharmacist, the patient, and the prescriber. 21 U.S.C. § 353a(a). Second, the compounded drug must be made from approved ingredients that meet certain manufacturing and safety standards, §§ 353a(b)(l)(A)-(B), and the compounded drug may not appear on an FDA list of drug products that have been withdrawn or removed from the market because they were found to be unsafe or ineffective, § 353a(b)(l)(C). Third, the pharmacist or physician compounding the drug may not “compound regularly or in inordinate amounts (as defined by the Secretary) any drug products that are essentially copies of a commercially available drug product.” § 353a(b)(l)(D). Fourth, the drug product must not be identified by the FDA as a drug product that presents demonstrable difficulties for compounding in terms of safety or effectiveness. § 353a(b)(3)(A). Fifth, in States that have not entered into a “memorandum of understanding” with the FDA addressing the distribution of “inordinate amounts” of compounded drugs in interstate commerce, the pharmacy, pharmacist, or physician compounding the drug may not distribute compounded drugs out of state in quantities exceeding five percent of that entity’s total prescription orders. § 353a(b)(3)(B). Finally ... the prescription must be “unsolicited,” § 353a(a), and the pharmacy, licensed pharmacist, or licensed physician compounding the drug may “not advertise or promote the compounding of any particular drug, class of drug, or type of drug,” § 353a(c).

Western States, 535 U.S. at 364-65, 122 S.Ct. 1497 (emphasis and footnote added).

“Shortly after passage of FDAMA, however, trouble arose. In 2002, in Western States, 535 U.S. at 368-77, 122 S.Ct. 1497, the Court invalidated the advertising-related provisions of FDAMA, affirming the Ninth Circuit’s holding that those portions were unconstitutional restrictions on commercial speech.” Med. Ctr., 536 F.3d at 391 Interestingly, in arguing (unsuccessfully) that FDAMA’s advertising provisions advanced a substantial government interest, the Secretary of the U.S. Department of Health and Human Services asserted the importance of

“preserv[ing] the availability of compounded drugs for those individual patients who, for particularized medical reasons, cannot use commercially available products that have been approved by the FDA---- [BJecause obtaining FDA approval for a new drug is a costly process, requiring FDA approval of all drug products compounded by pharmacies for the particular needs of an individual patient would, as a practical matter, eliminate the practice of compounding, and thereby eliminate availability of compounded drugs for those patients who have no alternative treatment.” The Government argues that eliminating the practice of compounding drugs for individual patients would be undesirable because compounding is sometimes critical to the care of patients with drug allergies, patients who cannot tolerate particular drug delivery systems, and patients requiring special drug dosages.

W. States, 535 U.S. at 368-69, 122 S.Ct. 1497 (emphasis added). The Supreme Court recognized the importance of these competing concerns; i.e., protecting the new drug approval process while simultaneously permitting traditional compounding’s continued existence:

Preserving the effectiveness and integrity of the FDCA’s new drug approval process is clearly an important governmental interest, and the Government has every reason to want as many drugs as possible to be subject to that approval process. The Government also has an important interest, however, in permitting the continuation of the practice of compounding so that patients with particular needs may obtain medications suited to those needs. And it would not make sense to require compounded drugs created to meet the unique needs of individual patients to undergo the testing required for the new drug approval process. Pharmacists do not make enough money from small-scale compounding to make safety and efficacy testing of their compounded drugs economically feasible, so requiring such testing would force pharmacists to stop providing compounded drugs. Given this, the Government needs to be able to draw a line between small-scale compounding and large-scale drug manufacturing. That line must distinguish compounded drugs produced on such a small scale that they could not undergo safety and efficacy testing from drugs produced and sold on a large enough scale that they could undergo such testing and therefore must do so.

Id. at 369-70, 122 S.Ct. 1497 (emphasis added). The Court ultimately found that conditioning an exemption from the FDA approval process on refraining from advertising was an inappropriate way to draw the “small-scale” versus “large-scale” distinction. Id. at 370-71, 122 S.Ct. 1497. In so holding, however, the Court noted that “[s]everal non-speech-related means of drawing a line between compounding and large-scale manufacturing might be possible here. First, it seems that the Government could use the very factors the FDA relied on to distinguish compounding from manufacturing in its 1992 Guide.” Id. at 372, 122 S.Ct. 1497. The Court further noted that it had been provided no reason why these factors, “alone or in combination, would be insufficient to prevent compounding from occurring on such a scale as to undermine the new drug approval process.” Id. at 373, 122 S.Ct. 1497 (emphasis added).

5. The 2002 and 2003 Guides and Beyond

In the wake of Western States, the FDA issued revised Compliance Policy Guides addressing compounding of human and animal drugs. See Med. Ctr., 536 F.3d at 391. Like the 1992 and 1996 Guides before them, the 2002 and 2003 Guides assert that compounded human and animal drugs are not exempt from the FDCA’s new drug approval, adulteration, or misbranding provisions. Id. And the updated Guides continue to assure pharmacists that the FDA will use its enforcement discretion against a compounding pharmacy only where the pharmacy’s activities raise the kinds of concerns normally associated with manufacturing. Id. Despite these overarching parallels, however, the new Guides make a number of policy departures from their predecessors.

In the 2002 Guide, which addresses human drugs, the FDA asserts that “all of [FDAMA] is now invalid” in light of the Ninth Circuit’s severability holding in Western States. 2002 Guide at 2. Despite this, the 2002 Guide appears to embrace FDAMA’s effusive attitude towards traditional pharmacy compounding. The focus of the guidance is the FDA’s desire to eradicate improper manufacturing, which, with regard to bulk drugs, is framed as an issue of scale:

FDA believes that an increasing number of establishments with retail pharmacy licenses are engaged in manufacturing and distributing unapproved new drugs for human use in a manner that is clearly outside the bounds of traditional pharmacy practice and that violates the Act. Such establishments and their activities are the focus of this guidance. Some “pharmacies” that have sought to find shelter under and expand the scope of the exemptions applicable to traditional retail pharmacies have claimed that their manufacturing and distribution practices are only the regular course of the practice of pharmacy. Yet, the practices of many of these entities seem far more consistent with those of drug manufacturers and wholesalers than with those of retail pharmacies. For example, some firms receive and use large quantities of bulk drag substances to manufacture large quantities of unapproved drug products in advance of receiving a valid prescription for them. Moreover, some firms sell to physicians and patients with whom they have only a remote professional relationship. Pharmacies engaged in activities analogous to manufacturing and distributing drugs for human use may be held to the same provisions of the Act as manufacturers.

2002 Guide at 3 (emphasis added). Apart from its use in the sentence “some firms receive and use large quantities of bulk drugs,” the word “bulk” appears only one other time in the 2002 Guide. A compounder’s use of bulk ingredients that are not “components of FDA approved drugs” is listed as a factor FDA will consider in bringing an enforcement action. Id. at 4.

The 2003 Guide, which addresses animal drug compounding, was, according to the FDA, issued “to ensure the consistency of its policies with regard to compounding of drugs intended for use in humans and in animals.” 2003 Guide at 2-3. From the outset, however, the 2003 Guide strikes a decidedly more hostile tone toward compounding than its human drug counterpart (as well as its 1996 predecessor):

There is a potential for causing harm to public health and to animals when drug products are compounded, distributed, and used in the absence of adequate and well-controlled safety and effectiveness data or adherence to the principles of contemporary pharmaceutical chemistry and current good manufacturing practices. Use of compounded drugs in animals can result in adverse reactions and animal deaths.

Id. at 2. Unlike the 1996 Guide and the AMDUCA regulations, the 2003 Guide makes no distinction between food and non food-producing animals. Further, the 2003 Guide contains no discussion about permitted compounding practices (apart from the use of extra-label drugs under AMDUCA), and instead announces that the FDA intends to target the compounding of animal drugs conducted “in a manner that is clearly outside the bounds of traditional pharmacy practice ... (e.g., compounding that is intended to circumvent the drug approval process and provide for the mass marketing of products that have been produced with little or no quality control or manufacturing standards to ensure the purity, potency, and stability of the product).” 2003 Guide at 3 (emphasis added).

However, the most noticeable departure in the 2003 Guide is the FDA’s policy regarding the use of bulk drug substances in compounded animal medications. While the 1996 Guide acknowledged the occasional utility of compounding from bulk, the circumstances under which doing so would not subject a pharmacist to potential regulatory action, and the permissibility of the practice for non food-producing animals, such statements are absent — without explanation — from the 2003 Guide. And despite the 2002 Guide’s allowance of compounding from bulk for human drugs so long as the bulk ingredients are FDA-approved, the 2003 Guide lists “[c]om-pounding finished drugs [for animals] ... from bulk substances” among the factors which “raise[] the kind[] of concern normally associated with a manufacturer.” Id. at 5.

Attached to the 2003 Guide is an appendix entitled “Appendix A: List of Bulk Drug Substances for Compounding and Subsequent Use in Animals to Which the CVM Would Not Ordinarily Object.” Id. at 7. The appendix lists nine such substances, but provides no explication or rationale of the FDA’s methodology for the approval of the listed substances to the exclusion of others. Nor does the 2003 Guide draw any distinctions based upon the scale of bulk compounding activity, implying that a pharmacist who compounds one animal medication from bulk for a non food-producing animal has committed a per se violation of the FDCA. Thus, under the 2002 and 2003 Guides, a pharmacist who compounds medication from bulk for ingestion by a horse is akin to a manufacturer and subject to an FDA enforcement action, while the same pharmacist compounding medication from bulk for ingestion by the human rider of that horse is not. This is so despite the 2002 Guide’s assertion that “all of [FDA-MA] is invalid” and the 2003 Guide’s stated intent to maintain consistency in the FDA’s policies regarding regulation of human and animal drugs.

Because the FDA considered the 2003 Guide’s policy changes to be “minor,” the agency did not publish a notice in the Federal Register or invite public comment prior to issuing it. 21 C.F.R. § 10.115 (setting forth “good guidance practices” for FDA to follow in developing, issuing and using guidance documents, which include notice-and-comment procedures for guidance documents which “[s]et forth changes in interpretation or policy that are of more than a minor nature”). Having been deprived the opportunity for public comment, Franck’s and a number of other compounding pharmacists, veterinarians, and related associations (including the Small Business Association’s Office of Advocacy), wrote letters to Congress and to the FDA’s CVM, expressing concern that the policies outlined in the 2003 Guide “would cause many animal patients to suffer needlessly.” (Davidson Dec. ¶ 48.) In turn, more than seventy members of Congress wrote separately to the FDA, reiterating the policy concerns of the veterinarians and pharmacists. (Id. at Ex. 6.) The Congressmen called it “disconcerting” that the Guide was “put into effect without the opportunity for public review and comment by stakeholders” and therefore asked “[FDA] to withdraw it and issue a revised [Guide] for public comment.” (Id.)

In September 2004, the FDA responded to the various complaints by issuing the following notice:

FDA is announcing its intention to draft and publish for public comment a revised Compliance Policy Guide (CPG) on veterinary pharmaceutical compounding. FDA anticipates that the draft CPG will be available for comment in the Fall of 2004.

The current CPG, published in July 2003, describes FDA’s present thinking on what types of veterinary compounding might be subject to enforcement action. FDA has received numerous letters from veterinarians, pet owners, compounding pharmacists, and associations expressing concern that the CPG lacks sufficient clarity on the circumstances in which veterinary compounding, particularly from bulk drugs, would be permitted. Many of the letters also disagreed with the current policy, stating that it was not within FDA’s legal authority, and complained about the lack of prior public comment. After meeting with several groups and considering the comments in the letters it has received FDA concluded that issuing a revised CPG is appropriate.

When it is available, the draft CPG will be posted on FDA’s Center for Veterinary Medicine (CVM) Website and a notice of availability will be published in the Federal Register.

CVM Updates: FDA to Revise Its Compliance Policy Guide on Veterinary Compounding, September 1, 2004, available at http://www.fda.gov/AnimalVeterinary/ NewsEvents/CVMUpdates/ucm048425.htm (last visited September 12, 2011) (emphasis added).

Despite its promise to do so, the FDA did not propose or issue any form of revised guidance in the fall of 2004.

In two separate letters to the FDA in June 2005, twenty-six Senators and seventy-two Congressmen voiced their continued displeasure over the agency’s failure to revise the 2003 Guide and subject it to notice and comment procedures. (Davidson Dec. Ex. 6.) The Congressmen noted that

The Agency’s failure to follow through on these commitments has serious consequences. While FDA has had more than ample time to act on its assurances to revise the CPGs, their failed promises to reissue these documents represents a significant threat to vulnerable patient populations, both humans and animals, served by compounding pharmacies. Patients are continually threatened with not being able to receive crucial, life-giving medications only available from compounding pharmacies. In addition, pharmacists are being forced to operate under flawed policy, potentially jeopardizing their livelihood and reputation in order to meet patients’ essential medication needs. Further, the FDA has substantially increased inspection and enforcement activities against compounding pharmacies in the last year, premised on the very documents that the agency acknowledges as flawed.

(Id.) (Letter from Congressmen Charles Bass and Mike Ross to Dr. Lester M. Crawford, Acting Commissioner, U.S. Food and Drug Administration (June 29, 2005) (emphasis added)).

The lawmakers requested that the FDA “undertake an immediate review of the reasons behind these delays and take the steps necessary to issue proposed CPGs for public review and comment.” (Id.) However, almost five years later, when FDA filed this enforcement action, and even to date, FDA has not issued the revised guidance it promised in 2004.

6. Medical Center

In 2006, a group of state-licensed compounding pharmacies that specialized in compounding prescription drugs for humans and non-food animals grew weary of waiting for the FDA’s promised revisions and brought suit challenging the agency’s new assertions of authority as memorialized in the 2002 and 2003 Guides. Med. Ctr. Pharm. v. Gonzales, 451 F.Supp.2d 854 (W.D.Tex.2006). The pharmacies sought broad-based injunctive relief, including: (i) a declaration that drugs compounded by licensed pharmacists were not “new drugs” or “new animal drugs” per se under the FDCA; (ii) a declaration that the FDA did not have the authority to declare compounding from bulk ingredients for non-food animals illegal; and (iii) an injunction to prevent the FDA from enforcing the 2003 Guide “which unilaterally declares that compounding from bulk ingredients for non-food animals is illegal.” Id. at 856-57. After reviewing § 321(p)(l) and § 321(v)(l), the district court noted “the new drug definitions might seem to indicate that compound drugs fall within their provisions.” Id. at 859. However, the court ultimately found that Western States, FDAMA, and the legislative history of the FDCA compelled the conclusion that “compound drugs are implicitly exempt from the [FDCA’s] new drug definitions.” Id. The court then used this implied exemption to conclude, inter alia, that: (i) compounding medications for non food-producing animals from bulk drugs was permissible because the resulting medications were not “new drugs,” rendering inapplicable the FDCA’s unsafe, misbranding and adulteration provisions; and (ii) the FDA could no longer enforce the 2003 Guide to the extent that it conflicted with the court’s analysis of the FDCA. Id. at 867-69.

On appeal, the FDA challenged the district court’s holdings that compounded drugs were- “uniformly exempt” from the FDCA’s “new drug” definitions, and that “drugs compounded from bulk ingredients for non-food animals do not violate the FDCA’s unsafe, adulteration, or misbranding requirements.” Med. Ctr., 536 F.3d at 393. The Fifth Circuit, after reviewing the FDCA in light of its legislative history, initially expressed sympathy for the pharmacies’ plight:

Given the apparent ubiquity of pharmacy compounding at the time Congress passed the FDCA [in 1938], it would have been unprecedented for the FDCA to regulate compounded drugs ... [I]t seems unlikely that Congress intended to force compounded drugs to undergo the new drug approval process, a requirement that would have made compounding nearly impossible and thus nonexistent. Construing the “new drug” definition in a way that makes compounding effectively unlawful appears inconsistent with the likely expectation that compounding would and should persist and with other provisions of the FDCA that expressly acknowledge the existence of compounding.

Id. at 398 (other footnotes omitted).

Ultimately, however, the Fifth Circuit agreed with the FDA that compounded drugs are “new drugs” and consequently must satisfy the FDCA’s new drug approval requirements. Id. at 394. The Court deflected the argument that this construction would eradicate “the universally-appreciated practice of compounding” because it refused to “infer an absurd result from a maximalist interpretation of the FDA’s authority where such authority is tempered by enforcement discretion.” Id. at 398-99. However, the Court conceded that such discretion would provide little reassurance to the pharmacies:

The Pharmacies may quite understandably find cold comfort in the FDA’s promised self-restraint. In light, however, of the agency’s statutorily-authorized enforcement discretion and demon strated willingness to accommodate traditional compounding’s continued existence, there is reason to think pharmacies would continue to compound even if compounded drugs were deemed “new drugs.” Construing the FDCA to give the FDA authority over compounding would thus not necessarily “lead to a result so bizarre that Congress could not have intended it.”

Nonetheless, it remains at least questionable that Congress would have intended such a large expansion of the FDA’s regulatory authority. And it remains no small burden for compounding pharmacists, as they put it, to “live in sin” — their livelihood having no greater assurance than the FDA’s good graces.

Id. at 399-400 (emphasis added and citation omitted).

Despite these misgivings, the Fifth Circuit found that Congress’ enactment of FDAMA made a “difficult case ... easy” because the amendment provided a “safe harbor” for compounding under certain conditions. Id. at 400, 405. When construing the statute in light of its amendment, the Court concluded that compounded drugs could not be “implicitly exempted” from the FDCA, as the district court had concluded, because “reading the ‘new drug’ definition implicitly to exclude compounded drugs would make [FDAMAJ’s explicit, conditional exceptions superfluous.” Id. at 405-06.

At the end of its lengthy opinion, the Court very briefly considered the district court’s conclusion that “drug products compounded in bulk by pharmacists and veterinarians are not ‘new animal drugs’ and therefore are not ‘adulterated,’ ‘unsafe,’ or ‘misbranded.’ ” Id. at 406-08. The Fifth Circuit declared AMDUCA a “similar amendment” to FDAMA, and thus concluded that although the amendments contain different provisions, “AMDUCA’s effect on construction of the ‘new animal drug’ definition is much the same as FDA-MA’s effect on construction of the ‘new [human] drug’ definition. AMDUCA suggests that the FDCA’s use of the term ‘new animal drug’ includes compounded drugs.” Id. at 407-08 (alteration in original). The Court explained this conclusion by finding that:

paragraph (4) [of AMDUCA] establishes that if a new animal drug is approved for one animal use, it can be used for a different unapproved use (i.e., compounded), and paragraph (5) provides that if a new drug is approved for human use, it can be used for a different unapproved animal use (i.e., compounded). In both cases, the drug must be used pursuant to the order of a licensed veterinarian and is subject to the FDA’s discretionary finding that it poses a risk to public health.

Id. at 408. As a result, the Court held— citing Algon and 9/1 Kg. Containers as additional support — “that compounded drugs are ‘new animal drugs’ ” under the FDCA, “[a]nd unless the compounded drugs are exempt under the FDCA’s AMDUCA provisions, § 360b(a)(4) and (5), compounded animal drugs are subject to FDCA’s unsafe, adulteration, and misbranding requirements. As with human drugs, the FDCA contains no blanket ‘implicit exemption’ for animal drugs produced by compounding.” Id. at 408 (emphasis added).

Now, for the first time, the FDA has brought an enforcement action under the FDCA seeking to enjoin a pharmacist from compounding veterinarian-prescribed medications from bulk.

IV. The Court’s Decision

A. Introduction

The FDA says this is a simple case: the literal, plain language of the original FDCA, enacted in 1938, gives it the enforcement authority to prevent pharmacists from bulk compounding medications for non food-producing animals. Thus, the FDA asserts that it is authorized to enjoin a licensed pharmacist’s state-authorized practice of compounding animal drugs from bulk substances, even where a single medication is compounded for an individual non food-producing animal pursuant to a valid veterinary prescription. Essentially, the FDA contends that this traditional compounding practice implicates the same concerns under the FDCA as the mass-production, mass-marketing, and mass-distribution of unapproved animal drugs by an unlicensed manufacturer.

Although the FDA’s complaint and declarations contain allegations that Franck’s has engaged in conduct indicative of a “manufacturer” of drugs, such as compounding commercially available drugs or compounding drugs in advance of a valid prescription, it has provided no factual support for such claims and ultimately does not rely on them to maintain this action. Further, despite the FDA’s allusions to Franck’s “large” and “interstate” operation, it has not sought to prove a statutory violation based on the size or breadth of Franck’s operation. Nor does the FDA contend that Franck’s has compounded from bulk substances so as to produce animal drugs which are actually unsafe for animal consumption or are not efficacious. See Doc. 47 at 37-38. Finally, though the FDA references the deaths of the Venezuelan polo horses, that tragic event was unrelated to the bulk compounding that the FDA targets in this suit. Thus, each of these matters proved to be irrelevant. Given the undisputed record in this case and the FDA’s broad view of its authority under the FDCA, this enforcement action could just as easily have been brought against a state-licensed “Mom- and-Pop” pharmacy for filling, through bulk compounding, one veterinary prescription for one horse.

Narrowing the inquiry even further, the FDA contends that it needs no more than the plain language of the 1938 FDCA to enjoin Franck’s bulk compounding, a position it asserts has been confirmed by three courts of appeal (the Seventh, Third, and Fifth Circuits in 9/1 Kg. Containers, Al gon, and Medical Center, respectively). The FDA expressly disclaims reliance upon any other legal source, including AMDUCA, (see Doc. 54 at 7 (“AMDUCA does not encompass compounding from bulk drugs”)); (Doc. 47 at 20 (“AMDUCA doesn’t touch what we have here in this case”)); FDAMA, (id. at 42 (“neither [FDAMA nor AMDUCA] are the subject of this suit”)); any FDA regulation; or the 2003 Guide, which it concedes does not have the force of law, (Doc. 54 at 30 (the 2003 Guide “is nothing more than an expression of a non-binding policy on enforcement discretion”)). Thus, reduced to its essence, the parties and the Court are joined on the central issue: whether the FDCA, as originally enacted in 1938, provides the FDA with statutory authority to enjoin Franck’s from engaging in traditional compounding of animal drugs from bulk.

Franck’s says that Congress, in passing the FDCA, never intended to allow the FDA to prohibit the long-standing and widespread practice of bulk compounding when done by a state-licensed, state-regulated pharmacist, acting on an individual prescription written by a veterinarian for a non food-producing animal. In the alternative, Franck’s contends that the FDA has failed to properly exercise this authority by failing to promulgate regulations through notice and comment rule-making before commencing this enforcement action.

The FDA acknowledges that, for over a half-century after enactment of the FDCA, it did not assert authority to regulate traditional pharmacy compounding. Despite this, the agency’s position is that the FDCA has always provided the FDA with authority to bring enforcement actions against pharmacists who compound animal drugs, and that its failure to do so in the past was merely the exercise of prosecutorial discretion. The FDA further asserts that it need not undertake rule-making before seeking to regulate in this area because its authority is supported by the plain language of the FDCA. The FDA thus concludes that, once it has shown a violation of the statute (i.e., that a “new animal drug” has been distributed without an approval or exemption in place), it enjoys unfettered enforcement discretion.

B. Discussion

“Because this case involves an administrative agency’s construction of a statute it administers, [this Court’s] analysis is governed by Chevron U.S.A. Inc. v. Natural Resources Defense Council, Inc., 467 U.S. 837, 104 S.Ct. 2778, 81 L.Ed.2d 694 (1984).” FDA v. Brown & Williamson Tobacco Corp., 529 U.S. 120, 132, 120 S.Ct. 1291, 146 L.Ed.2d 121 (2000). Under Chevron’s two-step approach, a reviewing court must first ask “whether Congress has directly spoken to the precise question at issue[, and i]f the intent of Congress is clear, that is the end of the matter; for the court, as well as the agency, must give effect to the unambiguously expressed intent of Congress.” Chevron, 467 U.S. at 842-43, 843 n. 9, 104 S.Ct. 2778 (“If a court, employing traditional tools of statutory construction, ascertains that Congress had an intention on the precise question at issue, that intention is the law .... ”). Second, if the Court finds that “the statute is silent or ambiguous with respect to the specific issue,” the Court will defer to the agency’s interpretation if it is “based on a permissible construction of the statute.” Chevron, 467 U.S. at 843, 104 S.Ct. 2778; see also Gonzales v. Oregon, 546 U.S. 243, 255, 126 S.Ct. 904, 163 L.Ed.2d 748 (2006) (“An [agency’s] interpretation of an ambiguous statute may ... receive substantial deference”) (citing Chevron, 467 U.S. at 842-45, 104 S.Ct. 2778).

In applying this two-step analysis, the Supreme Court found in Chevron that “ ‘[t]he power of an administrative agency to administer a congressionally created ... program necessarily requires the formulation of policy and the making of rules to fill any gap left, implicitly or explicitly, by Congress.’ ” Chevron, 467 U.S. at 843, 104 S.Ct. 2778 (quoting Morton v. Ruiz, 415 U.S. 199, 231, 94 S.Ct. 1055, 39 L.Ed.2d 270 (1974)). Thus, “a court may not substitute its own construction of a statutory provision for a reasonable interpretation made by the administrator of an agency.” Id. at 844, 104 S.Ct. 2778. However, the Court also recognized the judiciary’s role as “the final authority on issues of statutory construction.” Id. at 843 n. 9, 104 S.Ct. 2778. As a result, “a reviewing court ‘must reject administrative constructions ... that are inconsistent with the statutory mandate or that frustrate the policy that Congress sought to implement.’ ” Sierra Club v. Johnson, 541 F.3d 1257, 1265 (11th Cir.2008) (quoting Sec. Indus. Ass’n v. Bd. of Governors of Fed. Reserve Sys., 468 U.S. 137, 143, 104 S.Ct. 2979, 82 L.Ed.2d 107 (1984)). Further, “deference to the agency’s interpretation under Chevron is warranted only where ‘Congress has left a gap for the agency to fill pursuant to an express or implied delegation of authority to the agency.’ ” Am. Bar Ass’n v. F.T.C., 430 F.3d 457, 468 (D.C.Cir.2005) (“ABA I ”) (quoting Ry. Labor Exec. Ass’n v. Nat’l Mediation Bd., 29 F.3d 655, 671 (D.C.Cir.1994) (en banc)). Put differently, “the existence of [statutory] ambiguity is not enough per se to warrant deference to the agency’s interpretation. The ambiguity must be such as to make it appear that Congress either explicitly or implicitly delegated authority to cure that ambiguity.” Id. at 469.

1. The FDCA’s Language and the New Animal Drug Approval Process

“We begin, as courts always should in matters involving statutory interpretation, with the statutory language.” Durr v. Shinseki 638 F.3d 1342, 1344 (11th Cir.2011). The FDCA broadly defines “drug” to include “articles intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease in man or other animals.” 21 U.S.C. § 321(g)(1)(B). The term “new animal drug” is also broadly defined as

any drug intended for use for animals other than man ... the composition of which is such that such drug is not generally recognized, among experts qualified by scientific training and experience to evaluate the safety and effectiveness of animal drugs, as safe and effective for use under the conditions prescribed, recommended, or suggested in the labeling thereof.

Id. § 321(v)(l) (emphasis added). This definition provides no general exception for drugs created by compounding, nor a specific exemption for compounding by pharmacists. As the Fifth Circuit noted in Medical Center,

[T]he language of the FDCA’s “new drug” definition is both plain and expansive. A “new drug” is “any drug” the “composition of which” has not already been approved for use in accordance with its labeling. Compounded drugs are, after all, drugs. If a compounder changes the composition of an approved drug — by mixing or combining an approved drug with something else to create a different substance or by creating special dosage or delivery forms of an approved drug inconsistent with a drug’s labeling — t