Bioavailability of bromhexine tablets and preliminary pharmacokinetics in humans

The absorption of bromhexine from Bromhexin tablets 8 mg, DAK has been compared with that from Bisolvon® tablets 8 mg, Boehringer Ingelheim, in a two-way complete crossover study. Four tablets of each of the two bromhexine products, corresponding to a single dose of 32 mg of bromhexine hydrochloride (77.6 μmol), was administered to each of the 10 volunteers. The plasma concentration was followed over the 4-hour period following each administration. By means of Pratt's test for paired data no statistically significant difference (p > 0.10) between the two products was found with respect to maximum plasma concentration (89 and 84nmol.l−1, respectively), the times for their occurrence (1.3 and 1.0h, respectively), and the area under the plasma concentration-time curves (140 and 132 nmol.l−1.h, respectively). It is concluded that Bromhexin, DAK and Bisolvon® are bioequivalent. Provisional pharmacokinetic data for bromhexine, after oral administration, in man were obtained. The first-pass effect and the biological half-life were estimated by combining plasma and 30 h urine data from four of the volunteers. The first-pass effect was estimated to be c. 75 per cent, the biological half-life to be c. 6 h, and c. 0.1 per cent of the dose was found as unmetabolized bromhexine in the urine. The data indicate that the pharmacokinetics of bromhexine may be described as a two-compartment open model.