Abstract

QUALITY ASSURANCE AND COMPARATIVE STUDIES OF CARBAMAZEPINE TABLET GENERICS DISPENSED IN NIGERIAN PHARMACIES

Ukwueze S. E.*, Gbimadee B. K., Odigie J. and Ajibo D. N.

ABSTRACT

Carbamazepine is a drug of choice for the treatment of partial and tonic-clonic seizures. Its innovator brand, and other generic products are utilized interchangeably in many countries as an anticonvulsant, and for the treatment of peripheral neuralgia. These products are expected to be chemically and bio-pharmaceutically identical in order to achieve comparable therapeutic outcomes. The aim of this study was to carry out comparative quality assurance studies of different brands of carbamazepine tablets in some Nigerian pharmacies to predict their bioequivalence using various quality control tests. The study was done by carrying out tests such as weight uniformity, friability, disintegration and dissolution, amongst other tests, using standard procedures. The carbamazepine content was determined at a wavelength of 343 nm using UV-spectrophotometer, while the innovator brand (C1) was applied as the reference standard. The results showed that all the brands (C1, C2, C3, C4, and C5) complied with the weight uniformity (≤ 5-7.5 mg variation), friability (< 1.0%), and disintegration (< 15 min) tests, except crushing strength test which C4 failed (< 4 Kg/f). Only C2 failed the content uniformity test (87.73%). The dissolution profiles of the brands showed drug release of more than 80% within 30 min indicating high similarity and possibility of substitution of generic brands with the innovator product. In conclusion, the results of the study showed that though the drug brands could be prescribed interchangeably with the innovator brand, adequate care must be taken to monitor therapeutic outcomes while using various generic products of carbamazepine. This is to minimize variable patient response as a result of the slight deviations in quality parameters among the brands evaluated.

Keywords: Quality control, Carbamazepine, Disintegration, interchangeability, quality assurance.