Pharmaceutical Equivalence of Clarithromycin Oral Dosage Forms Marketed in Nairobi County, Kenya

Clarithromycin is a broad-spectrum semi-synthetic macrolide indicated for treatment of pneumonias, Helicobacter pylori, and chlamydial and skin infections. The object of this study was to evaluate the pharmaceutical equivalence of 14 generic clarithromycin products marketed in Nairobi County, Kenya, to the innovator products, using in vitro dissolution profiles and similarity factors (f₂). Further, dissolution profiles of four innovator formulations manufactured in different sites were compared. Fourteen clarithromycin tablets/capsules and four suspensions were subjected to assay and comparative dissolution runs at pH 1.2, 4.5 and 6.8, for 60 and 90 min, respectively. All products complied with pharmacopoeial assay specifications. However, significant differences were observed in their dissolution profiles. The non-compliance rates for tablets/capsules were 50% at pH 1.2, 33% at pH 4.5 and 50% at pH 6.8, while none of the four suspensions were compliant. Overall, only four (25%) products complied with the specifications for similarity factor. The results obtained indicate that a significant percentage of generic clarithromycin products are pharmaceutically non-equivalent to the innovator products, and that assay and single-point dissolution tests are insufficient demonstration of equivalence between the generic and innovator products.

Pharmaceutical quality of docetaxel generics versus originator drug product: a comparative analysis

INTRODUCTION

The aim of this study was to evaluate the quality of 31 commercially available generic formulations of docetaxel purchased in 14 countries by comparing their docetaxel content, impurity levels and pH versus those of the proprietary product Taxotere (Tx).

RESEARCH DESIGN AND METHODS

Generic formulations were purchased in 14 countries in Asia, Africa, the Middle East and Latin America. Levels of docetaxel and impurities (chromatographic peaks above 0.05%) were obtained for each sample using reverse-phase liquid chromatography with ultraviolet detection. The pH of aqueous solutions of generic docetaxel formulations and Tx was also measured. A global evaluation of quality was conducted on each product using a multicriteria desirability analysis based on standards defined by the International Conference on Harmonisation guidelines and the US Pharmacopeia paclitaxel injection monograph.

RESULTS

Most generic formulations contained a lower than expected amount of docetaxel and/or a high level of impurities: 21 generic docetaxel formulations had an average mass of docetaxel that was <90% of the expected mass and 23 generic docetaxel formulations had a total impurity content of >3.0%, almost twice the level of impurities in Tx 20 mg. In total, 33 impurities not present in Tx were detected in the generic samples. Desirability analysis demonstrated that none of the generic docetaxel formulations had composition characteristics similar to those of Tx.

CONCLUSIONS

This study demonstrated that from an analytical point of view, 90% of the generic docetaxel formulations evaluated contained insufficient active drug, high levels of impurities or both. This has the potential to affect both efficacy and safety of the drug.

Pharmaceutical quality of generic isotretinoin products, compared with Roaccutane

BACKGROUND

Isotretinoin is the drug of choice for the management of severe recalcitrant nodular acne. Several generic products are available. However, their pharmaceutical quality, in particular particle size distribution, which may affect safety and efficacy is unknown. Hence, prescribing of some generic products may be problematic.

OBJECTIVES

To assess the pharmaceutical quality of 14 generic isotretinoin products compared with Roaccutane (F. Hoffmann-La Roche Ltd).

RESEARCH DESIGN AND METHODS

Tests were performed according to Roche standard procedures, European and US pharmacopoeia specifications. Tests included isotretinoin content, identity and amount of impurities and degradation products, effect of accelerated shelf-life studies on stability, particle size distribution and composition of non-active ingredients.

RESULTS

The 14 isotretinoin products differed by 30-fold in median particle size and showed variation in their non-active ingredients. The average isotretinoin content of Acnotin and Acne-Tretin fell outside the 95-105% Roche specifications. Following accelerated shelf-life tests, only four products retained isotretinoin content within Roche specifications, whilst Acne-Tretin (the only powder formulation) lost 72.5% isotretinoin content. Two generic products exceeded the +/- 2% specification (Ph. Eur.) and a further three exceeded the +/- 1% (USP) for tretinoin content, eight exceeded the 2.54% specification for total impurities and six contained >or= 5 unknown impurities. Isotretinoin-5.6-epoxide content exceeded the 1.04% specification in five generic products.

CONCLUSIONS

Thirteen generic products failed to match Roaccutane in one or more tests and 11 failed in three or more tests. It cannot be assumed that all generic isotretinoin products are as therapeutically effective or safe as Roaccutane.

A Survey of the Quality of Generic???Clarithromycin Products from???18 Countries

OBJECTIVE

This study compared the quality of 65 generic clarithromycin products manufactured in 18 countries with that of the innovator product.

DESIGN

To assess quality, the generic products were examined visually, assayed by high-pressure liquid chromatography for clarithromycin content and impurities, tested for dissolution properties, and compared with the innovator product manufactured by Abbott Laboratories.

RESULTS

This survey found that many generic clarithromycin products were not equivalent to the innovator product and many of these generic products fell short of the approved specifications developed for the innovator product. Overall, 9% (6 of 65) of all generic tablets tested failed to contain between 95% and 105% of the clarithromycin claimed in the label, thus falling short of the approved registered specification for the innovator product. Seventeen percent (1 of 6) of tablets from Latin America (LA), 8% (3 of 38) of tablets from the Asia, Africa, Pacific (AAP) region, and 10% (2 of 21) of tablets from Europe did not contain the amount of clarithromycin drug content claimed in the label. A total of 34% (17 of 50) of the generic products tested released less drug in 30 minutes than did the innovator tablets. Although the majority of these generic products met the dissolution specification requiring that 80% of the drug must dissolve in 30 minutes, one generic product failed to meet this specification with 68% of drug dissolving in 30 minutes. Moreover, 19% (12 of 65) of all the generic products tested exceeded the Abbott Laboratories' 3% limit for total impurities in bulk drug, and 30% (20 of 65) exceeded the Abbott Laboratories' 0.8% limit for the known impurity 6,11 di-O-methyl erythromycin A.

CONCLUSIONS

These results demonstrated that generic tablets are often not comparable in vitro to the innovator product. These findings suggest that results achieved with branded clarithromycin (Abbott Laboratories) should not be extrapolated to generic products. In vivo studies would be needed to determine the clinical relevance of these findings.

A survey of the quality of generic clarithromycin products manufactured in Slovenia and Israel

This study evaluated the quality of 11 generic clarithromycin products obtained in Poland, Slovakia, Slovenia, or Israel and manufactured in Slovenia or Israel. The generic products were examined visually, assayed by high-pressure liquid chromatography for clarithromycin content and impurities, tested for dissolution properties, and compared with the innovator product manufactured by Abbott Laboratories. Fifty-five percent of generic products fell short of the specifications for the innovator product. Ten percent of the generic products did not contain the amount of clarithromycin claimed in the label; 18% released less drug than did the branded tablets in the standard dissolution assay. In light of these results, it is not possible to conclude that all generic tablets are of the same quality as the innovator product; clinical trial results achieved with branded clarithromycin should not be extrapolated to generic products.