A COMPARATIVE STUDY OF THE QUALITY OF DIFFERENT BRANDS OF AMITRIPTYLINE TABLETS AVAILABLE IN SOME NIGERIAN MARKETS
Ukwueze S.E.*, Andrew-Kekii L.P., Nwoke E.A. and Odigie J.
ABSTRACT
In recent times, generic brands of psychotropic medications have flooded the Nigerian market, thus, decreasing the cost of managing mental health disorders. However, the World Health Organization (WHO) had estimated that 30 % of the medicines in circulation in low- and middle-income countries, like Nigeria, are substandard and counterfeit. Poor quality medicine poses serious public challenge to end-users globally. The objective of this study was to evaluate the degree of compliance of different brands of amitriptyline, an antidepressant commonly used in Nigeria, with quality and safety standards. Generic brands of amitriptyline were sourced from pharmacies in south-south states of Nigeria and analyzed for uniformity of weight, hardness, friability, disintegration, and dissolution profiles. The content of active ingredients and similarity factor (F) of the dissolution profiles for the tablets were also determined. All the tests were done according to USP (2009) and BP (2016) specifications. Amitriptyline content was determined at a wavelength of 245 nm using UV-spectrophotometer. The innovator brand (R1) was applied as the primary standard. All the brands, except R1, failed the hardness test (< 4 kg/f) and the content of active ingredients assessment (< 90%). However, they all passed the friability test (< 1.0%), disintegration test (< 10 min) and dissolution test (> 80% at 30 min). Only one brand failed the similarity factor test (< 50). This study suggests that not all brands of amitriptyline available in Nigerian market meet the stringent quality and safety standards necessary to ensure efficacy and safety of the patient. This also makes outcome unpredictable when brands are switched.
Keywords: Amitriptyline, Substandard, Counterfeit, Pharmacopoeia, Medicines, Similarity factor.
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