Bioavailability of dextromethorphan (as dextrorphan) from sustained release formulations in the presence of guaifenesin in human volunteers
✍ Scribed by S. Demirbas; L. Reyderman; S. Stavchansky
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 144 KB
- Volume
- 19
- Category
- Article
- ISSN
- 0142-2782
No coin nor oath required. For personal study only.
✦ Synopsis
A multiple dose bioavailability study with six healthy male human volunteers was conducted. The bioavailability of an experimental sustained release tablet containing dextromethorphan hydrobromide (DXP-HBr), was compared with a marketed sustained release DXP-HBr suspension in a three-way crossover study. Plasma samples, collected serially after oral drug administration, were analysed for the major metabolite of dextromethorphan (DXP), dextrorphan (DX), using a specific HPLC method with fluorescence detection. The bioavailability parameters; area under the concentration-time curve (AUC), maximum plasma concentration (C max ), and time to peak (T max ), were obtained from the plasma concentration-time data. Additionally, pharmacokinetic parameters such as mean residence time (MRT), accumulation factor (R), fluctuation index (F i ), total body clearance (Cl), and the average concentration (C ( ) were estimated by using model independent kinetics approach. Analysis of variance of the data revealed that the presence of guaifenesin in the test formulation does not appear to have a statistically significant (p\ 0.05) effect on the bioavailability of dextromethorphan as dextrorphan. The relative bioavailability of the tablet dosage form with respect to the suspension was found to be 113% on Day 1 and 110% on Day 6.