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

Quality Assessment of Selected Essential Antimicrobial Drugs from Drug Retail Outlets of Selected Cities in Eastern Ethiopia

The prevalence of substandard and falsified (SF) antimicrobial drugs is increasing around the globe. This poses a great concern for the healthcare system. The consumption of SF antimicrobial drugs has the potential to result in treatment failure, emergence and development of antimicrobial resistance, and ultimately a rise in mortality rate. The objective of this study was to assess the quality of four commonly used antimicrobials marketed in the cities of Dire Dawa and Jijiga and the town of Togo-Wuchale, which have high potential for illegal drug trade activities in Ethiopia because they are located near the border with Somalia. A total of 54 brands/samples of amoxicillin, amoxicillin/clavulanic acid, ciprofloxacin, and norfloxacin formulations were collected covertly from 43 facilities using a convenience sampling strategy from March 16 to March 29, 2022. The samples were first screened using Global Pharma Health Fund (GPHF)-Minilab protocols and then analyzed using U.S. Pharmacopoeial and British Pharmacopoeia official methods. The quality evaluation detected no falsified product; however, it showed that 14.3% of the samples failed the GPHF-Minilab screening test semiquantitatively. Overall, 22.2% of the products analyzed did not meet any of pharmacopoeial specifications assessed: 13%, 12.2%, and 11.1% of the products failed in assay, dissolution, and weight variation, respectively. Additionally, 56.3% of amoxicillin samples, 60% of amoxicillin/clavulanate, 20% of ciprofloxacin, and 54.5% of norfloxacin samples were found to be pharmaceutically nonequivalent with their respective comparator products regarding dissolution profiles. The study showed the presence of substandard antimicrobial medicines in the eastern Ethiopian market.

In vitro comparative quality evaluation of different brands of carbamazepine tablets commercially available in Dessie town, Northeast Ethiopia

BACKGROUND

Good-quality drugs that fulfill the regulatory parameters and are produced per the current good manufacturing practice (cGMP) standards are very critical for the best therapeutic outcomes. However, the variety of branded drugs circulation in the market often put clinicians and pharmacists in a difficult situation of choice due to the possibility of interchangeability among brands, so we should ascertain the quality of the various brands of drugs, available in the drug market. The purpose of the study was to evaluate the quality and physicochemical equivalence of six brands of carbamazepine tablets that are commercially available in Dessie town, Northeast Ethiopia.

METHODS

An experimental study design was used. Six different brands of carbamazepine tablets were purchased from community pharmacies in Dessie town, Northeast Ethiopia, which were selected using simple random sampling methods. Identification, weight variation, friability, hardness, disintegration, dissolution test, and assay for the content of active ingredients were evaluated according to the procedures described in the United States Pharmacopeia (USP) and British Pharmacopeia (BP), and the results were compared with USP and BP standards. The difference (f1) and similarity (f2) factors were calculated to assess in vitro bioequivalence requirements.

RESULTS

The identification test results revealed that all samples contained the stated active pharmaceutical ingredients and all brands of carbamazepine tablets complied with the official specification for weight variation, friability, and hardness tests. The percentage concentration of carbamazepine was found in the range of 97.85 to 102.09, which met the USP specification of 92% to 108% of the stated amount. Similarly, all samples fulfilled disintegration time (i.e., ≤ 30 min) except brand CA1 (34.183 min) and dissolution tolerance limits (i.e., Q ≥ 75% at 60 min), which was found in the range of 91.673% -97.124%. The difference factor (f1) values were < 15 and the similarity factor (f2) values were > 50 for all the tested brands of carbamazepine tablets.

CONCLUSION

The present study revealed that all brands of carbamazepine 200 mg tablets met the quality control parameters as per pharmacopoeial specifications except the disintegration test of brand CA1, and could be used each brand interchangeably to achieve the desired therapeutic effect.

Manufacturing and Assessing the New Orally Disintegrating Tablets, Containing Nimodipine-hydroxypropyl-β-cyclodextrin and Nimodipine-methyl-β-cyclodextrin Inclusion Complexes

The aim of the present study was to manufacture new orally disintegrating tablets containing nimodipine-hydroxypropyl-β-cyclodextrin and nimodipine-methyl-β-cyclodextrin inclusion complexes. For obtaining a better quality of the manufactured tablets, three methods of the preparation of inclusion complexes, in a 1:1 molar ratio, were used comparatively; namely, a solid-state kneading method and two liquid state coprecipitation and lyophilization techniques. The physical and chemical properties of the obtained inclusion complexes, as well as their physical mixtures, were investigated using Fourier transformed infrared spectroscopy, scanning electron microscopy, X-ray diffraction analyses, and differential scanning calorimetry. The results showed that the lyophilization method can be successfully used for a better complexation. Finally, the formulation and precompression studies for tablets for oral dispersion, containing Nim-HP-β-CD and Nim-Me-β-CD inclusion complexes, were successfully assessed.

In vitro Comparative Quality Assessment of Different Brands of Furosemide Tablets Marketed in Northwest Ethiopia

Background

The use of ineffective and poor quality drugs endangers therapeutic treatment and may lead to treatment failure. For desired therapeutic effect, drugs should contain the appropriate amount of active pharmaceutical ingredient and the required physical characteristics.

Aim

The aim of this study was to evaluate quality as well as physicochemical bioequivalence of different brands of furosemide tablets marketed in Bahir Dar, Northwest Ethiopia.

Methods

Five different brands of furosemide tablets were purchased from community pharmacies in Bahir Dar city, Northwest Ethiopia. The quality control parameters of furosemide tablets were determined by identification, weight variation, disintegration, assay and dissolution tests and the results were compared with USP and BP pharmacopoeial standards. Difference (f1) and similarity (f2) factors were calculated to assess in vitro bioequivalence requirements.

Results

Identification test results revealed that all samples contained the stated active pharmaceutical ingredients. The results of weight variation tests indicated that all samples complied with USP specification limits. The active pharmaceutical ingredients quantitative assay showed that all the brands of furosemide tablets were between the 90% and 105% limit of label claim. Similarly, all samples fulfilled disintegration time (i.e., ≤30 min) and dissolution tolerance limits (i.e., Q ≥80% at 60 min). Hence, none of the samples were found to be counterfeit and/or substandard. Difference factor (f1) values were <15 and similarity factor (f2) values were >50 for all the tested brands of furosemide tablets.

Conclusion

This study revealed that all the furosemide brands met the quality specification of weight variation, hardness, friability, dissolution, disintegration and assay. The study also indicated similarity in the dissolution profile of the brands of furosemide tablets with the innovator product. Hence, all of these generic brands could be substituted with the innovator product in clinical practice.

In Vitro Dissolution and in Silico Modeling Shortcuts in Bioequivalence Testing

Purpose: To review in vitro testing and simulation platforms that are in current use to predict in vivo performances of generic products as well as other situations to provide evidence for biowaiver and support drug formulations development. Methods: Pubmed and Google Scholar databases were used to review published literature over the past 10 years. The terms used were “simulation AND bioequivalence” and “modeling AND bioequivalence” in the title field of databases, followed by screening, and then reviewing. Results: A total of 22 research papers were reviewed. Computer simulation using software such as GastroPlus™, PK-Sim^® and SimCyp^® find applications in drug modeling. Considering the wide use of optimization for in silico predictions to fit observed data, a careful review of publications is required to validate the reliability of these platforms. For immediate release (IR) drug products belonging to the Biopharmaceutics Classification System (BCS) classes I and III, difference factor (ƒ₁) and similarity factor (ƒ₂) are calculated from the in vitro dissolution data of drug formulations to support biowaiver; however, this method can be more discriminatory and may not be useful for all dissolution profiles. Conclusions: Computer simulation platforms need to improve their mechanistic physiologically based pharmacokinetic (PBPK) modeling, and if prospectively validated within a small percentage of error from the observed clinical data, they can be valuable tools in bioequivalence (BE) testing and formulation development.

Investigation to Explain Bioequivalence Failure in Pravastatin Immediate-Release Products

The purpose of this work is to explore the predictive ability of the biopharmaceutics classification system (BCS) biowaiver based on the dissolution methods for two pravastatin test products, where one of them showed bioequivalence (BE) while the other test failed (non-bioequivalence, or NBE), and to explore the reasons for the BE failure. Experimental solubility and permeability data confirmed that pravastatin is a BCS class III compound. The permeability experiments confirmed that the NBE formulation significantly increased pravastatin permeability, and could explain its higher absorption rate and higher C_max. This finding highlights the relevance of requiring similar excipients for BCS class III drugs. The BCS-based biowaiver dissolution tests at pH 1.2, 4.5, and 6.8, with the paddle apparatus at 50 rpm in 900 mL media, were not able to detect differences in pravastatin products, although the NBE formulation exhibited a more rapid dissolution at earlier sampling times. Dissolution tests conducted in 500 mL did not achieve complete dissolution, and both formulations were dissimilar because the amount dissolved at 15 min was less than 85%. The difference was less than 10% at pH 1.2 and 4.5, while at pH 6.8 f₂, results reflected the C_max rank order.

In Silico Prediction of Plasma Concentrations of Fluconazole Capsules with Different Dissolution Profiles and Bioequivalence Study Using Population Simulation

A biowaiver is accepted by the Brazilian Health Surveillance Agency (ANVISA) for immediate-release solid oral products containing Biopharmaceutics Classification System (BCS) class I drugs showing rapid drug dissolution. This study aimed to simulate plasma concentrations of fluconazole capsules with different dissolution profiles and run population simulation to evaluate their bioequivalence. The dissolution profiles of two batches of the reference product Zoltec^® 150 mg capsules, A1 and A2, and two batches of other products (B1 and B2; C1 and C2), as well as plasma concentration–time data of the reference product from the literature, were used for the simulations. Although products C1 and C2 had drug dissolutions < 85% in 30 min at 0.1 M HCl, simulation results demonstrated that these products would show the same in vivo performance as products A1, A2, B1, and B2. Population simulation results of the ln-transformed 90% confidence interval for the ratio of C_max and AUC_0–t values for all products were within the 80–125% interval, showing to be bioequivalent. Thus, even though the in vitro dissolution behavior of products C1 and C2 was not equivalent to a rapid dissolution profile, the computer simulations proved to be an important tool to show the possibility of bioequivalence for these products.