Bioequivalence study of montelukast tablets in healthy Pakistani volunteers

ABSTRACT

Montelukast is a leukotrien receptor antagonist used for asthma treatment. Objective of this study was to evaluate the bioequivalence of two montelukast 10mg tablets, Innovator drug [Singulair] as reference and other locally manufactured drug [Montiget] in 12 healthy volunteers. It was randomized, single dose, two-period crossover study with 1 week washout period. Blood samples [4-5 ml] were collected before and after drug administration and plasma was separated for analysis. Concentrations of montelukast at different time intervals were determined by validated UV-HPLC method at 345nm wavelength. Bioequivalence was assessed by using non compartmental approach and also calculated the 90% confidence interval of the least-squared pharmacokinetic parameters [C[max], AUC[0-t] and AUC[0-infinity]]. On average, C[max], AUC[0-t], AUC[0-inf], was 2.35 micro g/ml, 1.28 micro g.h./ml, 1.67 micro g.h./ml, for innovator drug and 2.53 micro g/ml, 1.53 micro g.h./ml, 1.96 micro g.h./ml, for test drug, respectively. Confidence interval [90%] for C[max], AUC[0-t] and AUC[0-inf] was 89-97%, 85-91% and 81-98% respectively. No statistical difference was found between the C[max] and AUC values of test and reference drugs. The confidence intervals for C[max], AUC[0-t] and AUC[0-infinity] are fully laid within the acceptable range of FDA [80-125%], thus two formulations are considered to be bioequivalent