Comparative Antiseizure Activities of Some Branded and Generic Antiepileptic Drugs in a Nigerian City

Abstract

Branded antiepileptic drugs (AEDs) are expensive, and in developing countries, cheaper generic equivalents may be used interchangeably. Therefore, this study aimed to compare the antiseizure activities of some available branded and generic AEDs in mice. The physicochemical properties of four generic and branded AEDs (carbamazepine, CAB; sodium valproate, SVP; phenytoin, PHY, and phenobarbitone, PHB) were determined according to pharmacopoeial methods. The organoleptic proper-ties, tablet hardness and thickness of the samples were also assessed. The anticonvulsant effect of AEDs was determined using maximal electroshock (MES) and pentylenetetrazole (PTZ) induced seizure. The samples of AEDs showed uniformly comparable organoleptic properties. The active moiety content for all the samples fell within the acceptable ranges stipulated in the official compendia. A significant statistical difference (p≤0.05) in disintegration time existed between two generic formulations of PHB, PHB01 (4.62±1.17 min), and PHB02 (1.40±0.26 min). Similarly, a significant statistical difference (p≤0.05) in hardness (10.40±0.15 kgF vs 5.61±0.03 kgF) and disintegration time (4.65±0.49 min vs 0.64±0.30 min) was observed between the two brands of CAB (CAB02 and CAB03 respectively). No significant statistical difference exists in mean recovery time between control (5.70±0.72 min) and treatment groups (CAB01, 6.50±0.65 min) in the MEST. In the PTZ test, there was a significant (p≤0.001) difference in the mean onset of clonic spasm between control (10.03±0.75 min) and PHB, PHB01 (17.50±0.99 min) 30 min post-treatment. In conclusion, no significant variation in the physicochemical and antiseizure activity of branded and generic formulations of AEDs was observed