Investigating the dissolution profiles of amoxicillin, metronidazole, and zidovudine formulations used in Trinidad and Tobago, West Indies

BCS-based biowaivers: Extension to paediatrics

A BCS-based biowaiver allows extrapolation of drug product bioequivalence (when applicable) based on the BCS class of the drug and in vitro dissolution testing. Drug permeability and solubility considerations for adult BCS might not apply directly to paediatric subpopulations and bridging of adult and paediatric formulations should be undertaken with caution. The aims of this study were to: (i.) identify compounds which would change drug solubility classification in the paediatric population, and (ii.) to assess the risk of extending BCS-based biowaiver criteria into paediatric products of these compounds. Amoxicillin, prednisolone, and amlodipine were selected as the model compounds. Dissolution studies of IR formulations of these compounds were conducted with USP II (paddle) and mini-paddle apparatus, in media of three pHs (pH 1.2, 4.5 and 6.8). Three dissolution setups were tested: (1) 'typical' BCS-based biowaiver conditions, (2) "BE" setup derived from BE study protocols (volume: 250 mL), and (3) "paediatric" setup based on representative volume for the paediatric population (50 mL). Results revealed that extension of regulated BCS-based biowaiver criteria for paediatric application is not as simple as scaling down volumes. It was further shown that BCS-based biowaiver criteria should not be applied when there is the risk of change of the drug solubility class, from the adult to paediatric populations. A deeper knowledge of the paediatric gastrointestinal environment is still lacking and would assist in refining the biopharmaceutical tools needed to appropriately evaluate formulation performance across age groups. This would potentially reduce the number of clinical studies required and speed up formulation development.

A comparative in vitro dissolution study of generic moxifloxacin immediate-release film coated tablets and referent pharmaceutical product

Dissolution testing of generic immediate release solid dosage forms represents a valuable tool to obtain dissolution profiles and to establish the similarity/dissimilarity between tested dosage forms. In this study, the in vitro dissolution profiles of generic immediate-release moxifloxacin (MOX) film coated tablets and a referent pharmaceutical product were compared and evaluated. The dissolution behavior of the generic product was investigated in three different dissolution media (pH=1.2, 4.5 and 6.8). The amount of dissolved MOX was determined using validated UV spectrophotometric method. For comparison of the dissolution behavior, the similarity factor, f2, was used. The dissolution profile of the generic product showed a release of >85 % MOX in the time frame of 30 min, in all the tested dissolution media. The similarity factor, f2, calculated from the comparison of the dissolution profiles of the generic and the referent pharmaceutical product in pH=1.2 dissolution medium was 50, 58, thus the products were established as similar. Based on the results of our study, the dissolution similarity between the generic MOX immediate-release film coated tablet and the referent product could be successfully used as a part of the approach to ensure their in vivo bioequivalence. Keywords: moxifloxacin, immediate-release solid dosage forms, dissolution, in vitro similarity

Quality Attributes and In Vitro Bioequivalence of Different Brands of Amoxicillin Trihydrate Tablets

Bacterial resistance and antibiotic drug effectiveness can be related to administering generic products with a subtherapeutic dose or poor in vivo drug release. The aim of this study was to investigate whether locally marketed amoxicillin tablets have the required chemical and physical attributes, including in vitro bioequivalence performance. Five generic products (T1, T2, T3, T4, and T5) containing combination of amoxicillin trihydrate and potassium clavulanate as 1 g strength present in immediate release tablets were compared to the reference listed drug product Augmentin® (R) for weight variation, friability, resistance to crushing, and chemical content of amoxicillin. Difference (ƒ1) and similarity (ƒ2) factors were calculated to assess in vitro bioequivalence requirements. The tablets from different products have shown compliance with the pharmacopeial requirements of the performed tests. The measured resistance to crushing of tablets did not influence the dissolution time. Three generic products released more than 85% of amoxicillin by the first 15 min as did the reference product and were considered as bioequivalent products. T1 and T4 had ƒ1 values of 16.5% and 25.4% respectively and their ƒ2 values were 44.5 and 34.6 respectively, indicating failure to meet in vitro bioequivalence requirements. Tablet formulations can play an important role in achieving bioequivalence. Independent investigations such as this study serve as an important tool to reveal possible inferior or noncompliant products that may find their way to the market.

Biowaiver Monograph for Immediate-Release Solid Oral Dosage Forms: Amoxicillin Trihydrate

Literature and experimental data relevant to waiver of in vivo bioequivalence (BE) testing for the approval of immediate-release solid oral dosage forms containing amoxicillin trihydrate are reviewed. Solubility and permeability characteristics according to the Biopharmaceutics Classification System (BCS), therapeutic uses, therapeutic index, excipient interactions, as well as dissolution and BE and bioavailability studies were taken into consideration. Solubility and permeability studies indicate that amoxicillin doses up to 875 mg belong to BCS class I, whereas 1000 mg belongs to BCS class II and doses of more than 1000 mg belong to BCS class IV. Considering all aspects, the biowaiver procedure can be recommended for solid oral products of amoxicillin trihydrate immediate-release preparations containing amoxicillin as the single active pharmaceutical ingredient at dose strengths of 875 mg or less, provided (a) only the excipients listed in this monograph are used, and only in their usual amounts, (b) the biowaiver study is performed according to the World Health Organization-, U.S. Food and Drug Administration-, or European Medicines Agency-recommended method using the innovator as the comparator, and (c) results comply with criteria for "very rapidly dissolving" or "similarly rapidly dissolving." Products containing other excipients and those containing more than 875 mg amoxicillin per unit should be subjected to an in vivo BE study.