FDA有关仿制药和抗肿瘤药说明书的2个指导原则介绍

美国食品药品管理局（FDA）于2022年1月发布了“参比制剂（RLD）说明书修订后简化新药申请（ANDA）说明书的修订”供企业用的指导原则草案。该指导原则提供了多种获取RLD说明书变更信息的方法，还告知提交修改后的仿制药说明书的具体资料。2020年11月FDA发布了“联合方案中的抗肿瘤药物的交叉说明书”供企业用的指导原则草案。所谓“交叉说明书”是指被批准用于联合方案的抗肿瘤药物的说明书纳入的相关信息。该指导原则指出，其中新药的交叉说明书“应包括有关联合用药安全有效的信息以及仅限于各自药物的信息”；而其中已批准的药物的交叉说明书，“应包括在联合方案中该药物与其他药物合用的安全有效性信息”。该指导原则还对交叉说明书一些具体项目的内容提出了建议。而我国目前尚没有类似的指导原则。详细介绍FDA这2个指导原则，期望对中国RLD说明书修订后的仿制药说明书的修订以及联合用药方案中的抗肿瘤药的“交叉说明”的实施有帮助；对这两种情况的说明书的监管也有所启迪。     

Bioequivalence of a generic metformin tablet preparation.

OBJECTIVE: The bioavailability of a generic preparation of metformin (Diabetmin from Hovid Sdn Bhd) was evaluated in comparison with a proprietary product (Glucophage from Lipha Pharma Ltd., UK). PATIENTS AND METHODS: Twenty-four healthy male volunteers participated in the study conducted according to a two-way crossover design. The bioavailability was compared using the parameters total area under the plasma concentration-time curve (AUC0-infinity), peak plasma concentration (Cmax and time to reach peak plasma concentration (Tmax). RESULTS: No statistically significant difference was observed between the values of the two products in all three parameters. Moreover, the 90% confidence interval for the ratio of the logarithmic-transformed AUC0-infinity and Cmax values of Diabetmin over those of Glucophage was found to lie between 0.94-1.03 and 0.94-1.06, respectively, being within the acceptable bioequivalence limit of 0.80-1.25. CONCLUSION: These findings indicate that the two preparations are comparable in the extent and rate of absorption. In addition, elimination rate constant (k(e)) and apparent volume of distribution (Vd) were calculated. There was no statistically significant difference between the values of the two preparations in the k(e) and Vd. Moreover, the values are comparable to those reported in the literature.     

Bioavailability and Bioequivalence: An FDA Regulatory Overview

Pharmaceutical Research - Bioavailability and/or bioequivalence studies play a key role in the drug development period for both new drug products and their generic equivalents. For both, these...     

Bioequivalence study of generic amlodipine in healthy Thai male volunteers

SUBJECTS, MATERIAL AND METHODS: To determine the bioequivalence of 10 mg generic amlodipine in healthy male volunteers, the reference and the test formulations were administered as a single oral dose after overnight fasting in a crossover study separated by 2-week washout interval. After dosing, serial blood samples were collected for a period of 144 h. Plasma amlodipine concentrations were determined by LC-MS/MS and the pharmacokinetic parameters were analyzed by non-compartmental analysis. RESULTS: The mean elimination half-life (t1/2) for the test (40 h) and the reference (44 h) were within the values previously reported. The rate of absorption reflected by tmax had a difference of -0.33 h, with a 90% CI of (-1.52)-0.85 (acceptable range +/- 1.3). Although the tmax of the test (5 h) was faster than the reference (6 h), the mean (90% CI) of the AUC(0-infinity) and Cmax ratios Test/Reference were 0.91 (0.87-0.97) and 1.01 (0.93-1.09), respectively. These values were within the range of 0.80-1.25, thus, the study demonstrated the bioequivalence of the 2 formulations.     

Bioequivalence in vitro evaluation of some antibacterial generic dosage forms

In this work, bioequivalence between generic and corresponding original brand-name dosage forms of some antibacterial drugs, frequently prescribed in developing countries, have been examined using in vitro dissolution testing. For this purpose, tablet or hard capsule formulations of five active substances (amoxycillin, ampicillin, co-trimoxazole (sulphamethoxazole/trimethoprim), metronidazole and penicillin V) have been retained. For each active substance, batch samples of three generic and one test formulations have been submitted to the pharmaceutical quality control and dissolution testing. Results obtained have shown that all samples examined met the specifications of quality edited by the pharmacopeias. On the other hand, interchangeability between generic and corresponding test formulations should be possible since their dissolution profiles are superposables enough.     

Bioequivalence study of a generic quetiapine in healthy male volunteers

Aim: To study the bioequivalence of a generic quetiapine (Quantia 200(R), manufactured by the Unison Laboratories Co., Ltd., Bangkok, Thailand) and the innovator product (Seroquel(R), AstraZeneca, Macclesfield, UK). Volunteers and methods: The study was a randomized, 2-way crossover design with a 2-week washout period in 24 healthy Thai male volunteers. After a single 200 mg oral dosing, serial blood samples were collected at appropriate interval up to 48 h. Plasma quetiapine concentrations were determined by high-performance liquid chromatography (HPLC). Pharmacokinetic parameters were estimated using the WinNonlin(R) software with noncompartment model analysis. Comparative bioequivalence between the two formulations was determined by analysis of variance (ANOVA) for 2-way crossover design. Results: The mean +/- SD of maximum plasma concentration (Cmax), the area under the plasma concentration-time curve from 0 - 48 h (AUC0-48) and the area under the plasma concentration-time curve from 0 to infinity (AUC0-inf) of Quantia 200(R) vs. Seroquel(R) were 886.60 +/- 356.50 vs. 811.34 +/- 323.37 ng/ml; 3,754.41 +/- 1,453.00 vs. 3,420.00 +/- 1,229.6 ng x h/ml and 4,015.35 +/- 1,528.25 vs. 3,769.45 +/- 1,296.69 ng x h/ml, respectively. Time to reach Cmax (tmax) of Quantia 200(R) and Seroquel(R) were 1.08 +/- 0.778 and 1.10 +/- 0.79 h, respectively, and thus not significantly different. The 90% confidence interval of the ratios of the logarithmically transformed of Cmax, AUC0-48 and AUC0-inf were 98.21 - 124.37%, 94.43 - 117.03% and 94.77 - 116.61%, respectively, which were within the acceptable range of 80 - 125%. Power of the test for Cmax, AUC0-48 and AUC0-inf was 92.1%, 96.9% and 97.4%, respectively. Conclusion: Quantia 200(R), used in this study, was bioequivalent to Seroquel(R) in terms of both the rate and extent of absorption.     

Bioequivalence testing of a new tablet formulation of generic fluoxetine.

The pharmacokinetics and relative bioavailability of fluoxetine capsules (reference) and tablets (test) were compared in 24 healthy subjects of both sexes after a single 20 mg oral dose of fluoxetine (as a hydrochloride salt). A randomized, crossover design with a 2-week wash-out period between each dose was applied. Serum samples, obtained before dosing and at various appropriate time points up to 192 hours, were analyzed for fluoxetine and norfluoxetine content by a simple, accurate and precise HPLC method. ANOVA, power analysis, 90% confidence intervals (CI), and two one-sided tests were used for the statistical analysis of pharmacokinetic parameters. The tolerability of the preparations was good. The respective point estimates of the ratios of the geometric means of log-Cmax and log-AUC(0-infinity) of fluoxetine were 0.912 and 0.935 with 90% of 0.838-0.992 and 0.857-1.020. The corresponding point estimates of norfluoxetine were 0.952 (90% CI = 0.843-1.075) and 0.904 (90% CI = 0.807-1.013), respectively. Since both 90% CI for the AUC(0-infinity). and Cmax geometric mean ratios of fluoxetine and norfluoxetine were included in the 80% to 125% interval proposed by the FDA the test drug (fluoxetine tablets) was considered bioequivalent to the reference one (Prozac capsules) according both to the rate and extent of absorption.     

FDA drug classification system.

The purpose and use of the FDA's classification system for new drug products are described. Investigational new drug applications (INDs) and new drug applications (NDAs) are submitted to the FDA's Center for Drug Evaluation and Research. To establish the priority of the product in the review process, expert reviewers classify each product according to chemical type and therapeutic potential. Drug products that receive a high therapeutic rating (e.g., 1AA or 1A) are reviewed for approval more quickly than drugs that receive a lower therapeutic rating (e.g., 1B or 1C). Because this system is the only national therapeutic rating system for drug products, it has been used in legislation, in clinical evaluation of new drug products as they are approved, and in formulary decisions. However, caution is needed because the therapeutic rating assigned at the time of the product's approval may not reflect its importance relative to all agents available at a later date. The FDA classification system was designed to guide new drug products through the application process and should be used only with caution for other purposes.     

FDA approves weight-management drug Contrave

On Sep. 10, 2014, the U.S. Food and Drug Administration approved Contrave （naltrexone hydrochloride and bupropion hydrochloride extended-release tablets） as treatment option for chronic weight management in addition to a reduced-calorie diet and physical activity.     

美国仿制药生物等效性评价的意义及方法

在美国,任何仿制药品上市,都必须经由美国食品药品监督管理局(FDA)批准.仿制药生产厂家须出示数据证明受试药品(仿制药品)与参比药品(原研药品)具有药学和生物等效性.生物等效性是指在相同的试验条件下,给予相同剂量的两种药学等效制剂,其活性成分吸收程度和速度无显著差异.     

Bioequivalence review for drug interchangeability.

To monitor the performance of the approved generic copies of a brand-name drug, we propose some methods in assessing bioequivalence among generic copies and the brand-name drug, and among generic copies themselves, using data from several bioequivalence studies adopting the standard 2 x 2 crossover design without carryover effects. We propose a meta-analysis method that increases statistical power when the between-subject variability is not large. A nonmeta-analysis is also considered. A numerical example of applying both methods is presented for illustration.     

Bioequivalence of abacavir generic and innovator formulations under fasting and fed conditions

OBJECTIVE: Abacavir sulfate is a synthetic carbocyclic nucleoside analogue indicated for the treatment of HIV-1 infection in combination with other antiretroviral agents. The objective of the current study was to determine the bioequivalence between a generic formulation of abacavir and the innovator product. MATERIAL AND METHODS: A total of 80 subjects were randomly assigned to receive a single 300 mg oral dose of abacavir sulfate as the generic (Ranbaxy-Abacavir, Ranbaxy Laboratories Ltd., equivalent to 300 mg of abacavir) and innovator (Ziagen, GlaxoSmithKline) tablet formulations in 2-way crossover studies performed under fasting (n=40) and fed (n=40) conditions. Multiple blood samples were collected over 14 hours and plasma concentrations of abacavir were assayed using an LC/MS/MS method with a limit of quantitation of 25.0 ng/ml. Pharmacokinetic (PK) parameters were calculated using noncompartmental methods. RESULTS: Under fasting conditions, geometric mean area under the curve from time 0 to the last measurable concentration (AUC(0-t)), area under the curve extrapolated to infinity (AUC(0-infinity) and maximum plasma concentrations (Cmax) of abacavir for the generic (5565 ng x h/ml, 5668 ng x h/ml and 2526 ng/ml, respectively) and innovator (5675 ng x h/ml, 5770 ng x h/ml and 2528 ng/ml, respectively) products were very similar. Under fed conditions, mean values of AUC(0-t) AUC(0-infinity) and Cmax for the generic (4487 ng x h/ml, 4571 ng x h/ml and 1841 ng/ml, respectively) and innovator (4574 ng x h/ml, 4654 ng x h/ml and 1781 ng/ml, respectively) formulations were also very similar. Ratios of LSM and 90% confidence intervals of PK parameters between the 2 formulations were within 80.0 - 125.0% under fasting and fed conditions, suggesting that the 2 tablet formulations resulted in similar rate and extent of bioavailability. Adverse events for the generic and innovator products were similar in nature and frequency in the fasting and fed studies. CONCLUSIONS Based on the above results, the generic tablet formulation of abacavir developed by Ranbaxy should be equally effective as the innovator product.     

Objective evaluation of generic drug information

Pharmacists active in health care venues need to be able to evaluate generic drugs in terms of effectiveness, safety, and economy to ensure that they are used appropriately. As part of the ongoing study of these factors, we carried out an objective evaluation of information provided for generics. A minimum of 20 commercially available products was considered for each pharmaceutical ingredient. The information subjected to evaluation consisted of the text of drug package inserts and information noted on interview forms. Using our own criteria for evaluating drug information, we attempted to quantify the amounts of information provided. Then, based on the numerical values obtained, we calculated information quantities with reference to drug prices to study the relationship between prices and available information for original drugs and their later-developed, generic equivalents. A total of 14 different pharmaceutical ingredients (327 product items) were considered, with the information quantity for generics amounting to 27.9+/-17.8-46.3+/-21.4% (Mean+/-S.D.) that for the original drugs. Examined on the basis of individual pharmaceutical companies, the corresponding ratio came to 15.1+/-7.8-62.4+/-6.4% (Mean+/-S.D.). For generics, the relationship between drug price (expressed against a value of 1.0 for original drugs) and information quantity (Qua(i)) came to 0.79+/-0.46-1.90+/-0.79% (Mean+/-S.D.). These results clearly point to the importance of evaluating information quantity for generic drugs on a maker-by-maker basis.     

Evaluation of the Proposed FDA Pilot Dose-response Methodology for Topical Corticosteroid Bioequivalence Testing

Pharmaceutical Research -     

Evaluation of the Proposed FDA Pilot Dose-Response Methodology for Topical Corticosteroid Bioequivalence Testing

Purpose. The American FDA has recently released a Guidance document for topical corticosteroid bioequivalence testing. The purpose of this study was to evaluate the recommendations of this document for appropriateness. The new specifications require a dose-vasoconstriction response estimation by the use of a Minolta chromameter in a preliminary pilot study to determine the parameters for use in a pivotal bioequivalence study. Methods. The visually-assessed human skin blanching assay methodology routinely practiced in our laboratories was modified to comply with the requirements of the pilot study so that visual and chromameter data could be compared. Two different cream formulations, each containing 0.12% betamethasone 17-valerate, were used for this comparison. Results. Visual data showed the expected rank order of AUC values for most dose durations whereas the chromameter data did not show similar results. The expected rank order of AUC values for both chromameter and visual data was not observed at very short dose durations. In fitting the data to pharmacodynamic models, equivalent goodness of fit criteria were obtained when several different parameter estimates were used in the model definition, however the visual data were best described by the sigmoid E_max model while the chromameter data were best described by the simple E_max model. Conclusions. The E_max values predicted by the models were close to the observed values for both data sets and, in addition, excellent correlation between the AUC values and the maximum blanching response (R_max) (r > 0.95) was noted for both methods of assessment. The chromameter ED₅₀ values determined in this study were approximately 2 hours for both preparations. At this dose duration the instrument would not be sensitive enough to distinguish between weak blanching responses and normal skin for bioequivalence assessment purposes.