Quality control of some antiepileptic drugs in the Iranian pharmaceutical market

摘要

Pharmaceutical products are regularly tested in terms of their quality specifications prior to their approval for market authorization. Assay and content uniformity tests are two main aspects of drug quality assessments. The assay value reflects the mean active content in a production batch. The content uniformity test shows the distribution of the active ingredient within the production batch. Assessment of the amount of active ingredient and confirmation of the claim on the label increase confidence in both the prescription and consumption of the dosage forms. The aims of this study were to evaluate the physicochemical properties (assay, content uniformity, release rate, friability, hardness and weight variation) of the most commonly used antiepileptic drugs on the Iranian pharmacy market (carbamazepine, phenobarbital and phenytoin). For this evaluation, several available commercial products of the above drugs including 11 produced by 7 manufacturers were collected and the above-mentioned tests were carried out. High-performance liquid chromatography (HPLC) was used to assay the active ingredients. The results indicated that all formulations except one of phenobarbital products (B7) passed the pharmacopoeial criteria for assay and content uniformity. All formulations demonstrated acceptable release rates and there was no significant difference among the dissolution profiles of similar products. All the formulations had appropriate hardness and their disintegration and dissolution were not affected by the hardness. Only one of carbamazepine products (A1) was found to have higher friability and others were in acceptable ranges. In conclusion, it seems that reformulation of few products is necessary.