Quality of albendazole tablets legally circulating in the pharmaceutical market of Addis Ababa, Ethiopia: physicochemical evaluation.

Background: Parasitic diseases are the main challenge of livestock production in the world. They are mainly controlled by the use of anthelmintic drugs. To be effective, the drugs should contain the appropriate amount of active pharmaceutical ingredient (API) and have the required physical characteristics. In this study, qualitative and quantitative assessments were performed to evaluate the quality of different brands of albendazole tablets legally circulating in pharmaceutical markets of Addis Ababa, Ethiopia.

Methods: Ultraviolet-Visible Spectroscopy (UVS), Fourier Transform Infrared Spectroscopy (FTIR) and High-Performance Liquid Chromatography (HPLC) were used for identification. Quantitative analysis was performed by HPLC. United States Pharmacopeia standard was used as a control to evaluate the identity and content of the API in the samples. A total of 10 batches of albendazole tablets from six different brands were collected and evaluated.

Results: All brands of albendazole tablets, except one, had acceptable physical characteristics. There was gross contamination in one batch, weight variation in 4 (40%) batches, and absence of package insert in 2 (20%) batches. All three methods of evaluation (UVS, FTIR and HPLC) confirmed that all batches passed the identity test. Quantitative analysis showed that no batch had API above the acceptable limit. However, 30% of batches from three different brands contained lower amount of API per tablet than the acceptable limit.

Conclusions: All batches of albendazole circulating in the market in Addis Ababa did not fulfil either physical or chemical quality standards. The most important finding of this research was the presence of drugs with lower level of API than the acceptable limit. This can lead to treatment failure and favour the emergence of parasites that are resistant to drugs. Therefore, there should be a thorough evaluation of drugs before approval. The study also revealed the importance of occasional assessment of drugs circulating even in the legal market.