Over-the-Counter Drug ProductsOver-the-Counter (OTC) drug products are those drugs that are available to consumers without a prescription. There are more than 80 classes (therapeutic categories) of OTC drugs, ranging from acne drug products to weight control drug products. As with prescription drugs, CDER oversees OTC drugs to ensure that t
hey are properly labeled and that their benefits outweigh their risks.OTC drugs play an increasingly vital role in America's health care system by providing easy access to certain drugs that can be used safely without the help of a health care practitioner. This enables consumers to take control of their own health care in many situations. There are more than 100,000 OTC drug products
marketed, encompassing about 800 significant active ingredients. Most OTC drug products have been marketed for many years, prior to the laws that require proof of safety and effectiveness before marketing. For this reason, FDA has been evaluating the ingredients and labeling of these products as part of "The OTC
Drug Review Program." The goal of this program is to establish OTC drug monographs for each class of products. OTC drug monographs are a kind of "recipe book" covering acceptable ingredients, doses, formulations, and labeling. Monographs will continually be updated adding additional ingredients and labeling as needed. Products conforming to a monograph may be marketed without further FDA clearance, while those that do not, must undergo separate review and approval through the "New Drug Approval System." The NDA system--and not the monograph system--is also used for new ingredients entering the OTC marketplace for the first time. For example, the newer OTC products [previously available only by prescription] are first approved through the NDA system and their "switch" to OTC status is approved via the NDA syst
em.FDA's review of OTC drugs is primarily handled by CDER's Division of Over-the-Counter Drug Products in the Office of Drug Evaluation V. However, scientists and regulators throughout CDER, the Office of General Counsel, and other Centers within FDA are routinely asked to assist in this massive effort. There is also an advisory committee, "The Nonprescription Drug Advisory Committee," which meets regularly to a
ssist the agency in evaluating issues surrounding these products.
The FDA Process for The FDA Process for Approving Generic DrugsApproving Generic Drugs
Gary J . Buehler, R.Ph.Gary J . Buehler, R.Ph. Dale Conner, Pharm. D.Dale Conner, Pharm. D.
DirectorDirector DirectorDirector, Division of , Division of
BioequivalenceBioequivalence
Office of Generic DrugsOffice of Generic Drugs
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Did you know that generic drugs...Did you know that generic drugs...
•• Are safe and effective alternatives to brand Are safe and effective alternatives to brand name prescriptionsname prescriptions
•• Can help both consumers and the Can help both consumers and the government reduce the cost of prescription government reduce the cost of prescription drugsdrugs
•• Are currently used in 50% of all Are currently used in 50% of all prescriptions dispensedprescriptions dispensed
•• Save an average of $50 for every Save an average of $50 for every prescription soldprescription sold
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HatchHatch--Waxman Amendments Waxman Amendments to FFD&C Act to FFD&C Act -- 19841984
•• Considered one of the most successful Considered one of the most successful pieces of legislation ever passedpieces of legislation ever passed
•• Created the generic drug industryCreated the generic drug industry
•• Increased availability of genericsIncreased availability of generics•• 1984 12% prescriptions were generic1984 12% prescriptions were generic
•• 2000 44% prescriptions were generic 2000 44% prescriptions were generic -- yet only yet only 8% of revenue for prescription drugs8% of revenue for prescription drugs
•• Compromise legislation to benefit both Compromise legislation to benefit both brand and generic firmsbrand and generic firms
Continued
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HatchHatch--Waxman Amendments Waxman Amendments to FFD&C Act to FFD&C Act -- 19841984
•• Allowed generic firms to rely on findings Allowed generic firms to rely on findings of safety and efficacy of innovator drug of safety and efficacy of innovator drug after expiration of patents and after expiration of patents and exclusivities (do not have to repeat exclusivities (do not have to repeat expensive clinical and preexpensive clinical and pre--clinical trials)clinical trials)
•• Allowed patent extensions and Allowed patent extensions and exclusivities to innovator firmsexclusivities to innovator firms
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Brand Name Drug Generic DrugNDA Requirements ANDA Requirements
1. Chemistry 1. Chemistry2. Manufacturing 2. Manufacturing3. Controls 3. Controls4. Labeling 4. Labeling5. Testing 5. Testing6. Animal Studies7. Clinical Studies 6. Bioequivalence8. Bioavailability
NDA vs. ANDA Review ProcessNDA vs. ANDA Review Process
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What are the requirements for What are the requirements for a generic drug?a generic drug?
•• LabelingLabeling
•• Chemistry/MicrobiologyChemistry/Microbiology
•• BioequivalenceBioequivalence
•• LegalLegal
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How do we assure the quality How do we assure the quality of generic drugs?of generic drugs?
•• First 5 steps of review process are identical First 5 steps of review process are identical to NDA processto NDA process
•• Bioequivalence for complicated products is Bioequivalence for complicated products is discussed with the same staff that reviewed discussed with the same staff that reviewed the brand productthe brand product
•• FDA has experience with the productFDA has experience with the product
•• Scientific literature publishedScientific literature published
•• Product is known to be safeProduct is known to be safe
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Generic Generic Drug Drug Review Review ProcessProcess
Bioequivalence Review
Labeling Review
Chemistry & Micro Review
Request for Plant Inspection
APPLICANT
ANDA
Acceptable &
Complete
Application Review
N Chem/ Micro
OK?
Labeling
OK?Bioequivalence
OK?
PreApprovalI nspection Results
OK?
Not Approvable
Letter
Approval Withheld
until Results Satisfactory
Bio Deficiency
LetterAPPROVED ANDA
NN N
N
Y Y Y
Y
Y
Refuse to Receive Letter
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What are the requirements for What are the requirements for a generic drug?a generic drug?
•• Same active ingredient(s)Same active ingredient(s)
•• Same route of administrationSame route of administration
•• Same dosage formSame dosage form
•• Same strengthSame strength
•• Same conditions of useSame conditions of use
Compared to reference listed drug (RLD) Compared to reference listed drug (RLD) -- (brand name product)(brand name product)
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LabelingLabeling
•• ““SameSame”” as brand name labelingas brand name labeling
•• May delete portions of labeling May delete portions of labeling protected by patent or exclusivityprotected by patent or exclusivity
•• May differ in excipients, PK data and May differ in excipients, PK data and how suppliedhow supplied
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ChemistryChemistry
•• Components and compositionComponents and composition
•• Manufacturing and controlsManufacturing and controls
•• Batch formulation and recordsBatch formulation and records
•• Description of facilitiesDescription of facilities
•• Specs and testsSpecs and tests
•• PackagingPackaging
•• StabilityStability
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Manufacturing Compliance Manufacturing Compliance ProgramsPrograms
•• Purpose Purpose -- To assure quality of To assure quality of marketed drug productsmarketed drug products
•• Mechanisms Mechanisms -- Product TestingProduct Testing
–– SurveillanceSurveillance
–– Manufacturing/Testing plant inspectionsManufacturing/Testing plant inspections
–– Assess firmAssess firm’’s compliance with good s compliance with good manufacturing processesmanufacturing processes
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U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICESPUBLIC HEALTH SERVICE
FOOD AND DRUG ADMINISTRATIONCENTER FOR DRUG EVALUATION AND RESEARCH
OFFICE OF GENERIC DRUGS
APPROVEDDRUG PRODUCTS
WITHTHERAPEUTIC EQUIVALENCE EVALUATIONS
23rdEDITIONTHE PRODUCTS IN THIS LIST HAVE BEEN APPROVED UNDER
SECTION 505 OF THE FEDERAL FOOD, DRUG, ANDCOSMETIC ACT.
2003
Electronic Orange Book -
http://www.fda.gov/cder/ob/
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•• All FDA approved drug products listed All FDA approved drug products listed (NDA(NDA’’s, OTCs, OTC’’s & ANDAs & ANDA’’s)s)
–– Therapeutic equivalence codesTherapeutic equivalence codes
““AA”” = Substitutable= Substitutable
““BB”” = Inequivalent, NOT Substitutable= Inequivalent, NOT Substitutable
–– Expiration dates: patent and exclusivityExpiration dates: patent and exclusivity
–– Reference Listed Drugs/brand drugs Reference Listed Drugs/brand drugs identified by FDA for generic companies identified by FDA for generic companies to compare with their proposed productsto compare with their proposed products
“Orange BookOrange Book”
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Definition of BioequivalenceDefinition of Bioequivalence
Pharmaceutical equivalents whose rate Pharmaceutical equivalents whose rate
and extent of absorption are not and extent of absorption are not
statistically different when statistically different when
administered to patients or subjects administered to patients or subjects
at the same molar dose under similar at the same molar dose under similar
experimental conditionsexperimental conditions
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Purpose of BEPurpose of BE
•• Therapeutic equivalence (TE)Therapeutic equivalence (TE)
•• Bioequivalent products can be Bioequivalent products can be substituted for each other without any substituted for each other without any adjustment in dose or other additional adjustment in dose or other additional therapeutic monitoringtherapeutic monitoring
•• The most efficient method of assuring The most efficient method of assuring TE is to assure that the formulations TE is to assure that the formulations perform in an equivalent mannerperform in an equivalent manner
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Model of Oral Dosage Form Model of Oral Dosage Form PerformancePerformance
TherapeuticEffect
Dosage Form
Gut WallDrug in Solution
BloodSite of Activity
Pharmacokinetic MeasurementDosage Form
Performance
Clinical/ PD Measurement
ln DoseDose
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Clinical/ PD DoseClinical/ PD Dose--ResponseResponse
Clin
ical
/PD
Res
pon
se
Log Dose
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Plasma ConcentrationPlasma Concentration--DoseDose
Dose
Pla
sma
Con
c.
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Approaches to Determining Approaches to Determining Bioequivalence (21 CFR 320.24)Bioequivalence (21 CFR 320.24)
•• In vivo measurement of active In vivo measurement of active moiety or moieties in biologic moiety or moieties in biologic fluidfluid
•• In vivo pharmacodynamic In vivo pharmacodynamic comparisoncomparison
•• In vivo limited clinical In vivo limited clinical comparisoncomparison
•• In vitro comparisonIn vitro comparison
•• Any other approach Any other approach deemed appropriate by FDAdeemed appropriate by FDA
FeV1 AlbuterolBlanching StudyTopical Corticosteroid
TopicalsNasal Suspensions
Questran - Binding StudiesNasal Solutions-Sprayer EvaluationPropofol - Droplet Size
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•• SingleSingle--dose, twodose, two--way crossover, fastedway crossover, fasted
•• SingleSingle--dose, twodose, two--way crossover, fedway crossover, fed
•• AlternativesAlternatives
–– SingleSingle--dose, parallel, fasteddose, parallel, fasted
–– SingleSingle--dose, replicate designdose, replicate design
–– MultipleMultiple--dose, twodose, two--way way crossover, fastedcrossover, fasted
–– Clinical endpoint studyClinical endpoint study
Study DesignsStudy Designs
Long Half-Life (wash-out)
Amiodarone, Etidronate
Highly Variable Drugs
Less Sensitive
Clozapine (Patient Trials)
Chemotherapy Trials
Topicals
Nasal Suspensions
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Waivers of I n Vivo Study Waivers of I n Vivo Study RequirementsRequirements
•• DefinitionDefinition
•• Criteria (21 CFR 320.22)Criteria (21 CFR 320.22)
–– In vivo bioequivalence is selfIn vivo bioequivalence is self--evidentevident
–– Parenteral solutionsParenteral solutions
–– Inhalational anestheticsInhalational anesthetics
–– Topical (skin) solutionTopical (skin) solution
–– Oral solutionOral solution
–– Different proportional strength of product Different proportional strength of product with demonstrated BEwith demonstrated BE
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Statistical Analysis Statistical Analysis (Two One(Two One--sided Tests Procedure)sided Tests Procedure)
•• AUC and CmaxAUC and Cmax
–– 90% Confidence Intervals (CI ) must fit 90% Confidence Intervals (CI ) must fit between 80%between 80% --125%125%
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Statistical Analysis Statistical Analysis 80 80 -- 125 %125 %
•• What does this mean?What does this mean?
•• Can there be a 46% difference?Can there be a 46% difference?
•• What is a point estimate?What is a point estimate?
•• What is a confidence interval?What is a confidence interval?
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Statistical AnalysisStatistical Analysis
•• Bioequivalence criteriaBioequivalence criteria
–– Two oneTwo one--sided tests proceduresided tests procedure
•• Test (T) is not significantly less than Test (T) is not significantly less than referencereference
•• Reference (R) is not significantly less than Reference (R) is not significantly less than testtest
•• Significant difference is 20% (Significant difference is 20% ( = 0.05 = 0.05 significance level)significance level)
–– T/R = 80/100 = 80%T/R = 80/100 = 80%
–– R/T = 80% (all data expressed as T/R so R/T = 80% (all data expressed as T/R so this becomes 100/80 = 125%)this becomes 100/80 = 125%)
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Possible BE Results (90% CI )Possible BE Results (90% CI )
T/R (%)80% 125%
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Narrow Therapeutic Range (NTI ) Narrow Therapeutic Range (NTI ) DrugsDrugs
•• Drug Products that are subject to Drug Products that are subject to therapeutic drug concentration or therapeutic drug concentration or pharmacodynamic monitoringpharmacodynamic monitoring
–– Examples are: Digoxin, Lithium, Examples are: Digoxin, Lithium, Phenytoin, WarfarinPhenytoin, Warfarin
•• Traditional bioequivalence limit of 80Traditional bioequivalence limit of 80--125% is unchanged for these 125% is unchanged for these productsproducts
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Contacting the OGDContacting the OGD
Contact: Contact: Office of Generic DrugsOffice of Generic Drugs
FDA/CDER (HFDFDA/CDER (HFD--600)600)
7500 Standish Place7500 Standish Place
Rockville, MD 20855Rockville, MD 20855
phone: 301phone: 301--827827--58455845
Web site: Web site:
www.fda.gov/cder/ogd/ index.htmwww.fda.gov/cder/ogd/ index.htm