Comparative bioavailability study of two salbutamol tablets in healthy adult volunteers

This Study was carried out to compare the rate and extent of absorption of a generic salbutamol in oral dosage form (Brethmol, 4mg) with the proprietary equivalent product (Ventolin (R), 4mg), in healthy adult subjects, under fasting conditions. The study was a single dose, randomized, two way crossover study with a four-week washout period. It involved 22 healthy Volunteers who received a single dose (4mg) of the test and the reference products after an overnight fast of at least 10 hours. Blood samples were collected at pre-dose and a serial of 14 samples were collected from each of the subject from I h until 48 h post-dose. Plasma concentrations of salbutamol were analyzed using GCMS method. The mean AUC(0-infinity), values were 91.26 and 96.45 h.ng/ml for reference and test product, respectively. The mean C(max) values were 12.26 and 12.38 ng/ml and the mean values were 2.80 and 2.33 hours for reference and test product, respectively. Analysis of variance showed that the 90% confidence intervals on the relative difference of the ratio for the AUC(0-infinity) and tile C(max) for the test and reference products were contained within the bioequivalence limit (80 - 125%) (C(max): 89-8 - 110.5% and AUC(0-infinity): 91.6 - 121.5%). There was no statistically significant difference for the t(max) between the test and reference formulations (p = 0.30). The test formulation was found to be bioequivalent to the reference formulation with regard to AUC(0-infinity), and C(max). There was no statistically significant difference in Brethmol and Ventolin (R) t(max). In Conclusion, Brethmol and Ventolin (R) are bioequivalent in healthy subjects.