Analytical Sciences


Abstract − Analytical Sciences, 21(12), 1515 (2005).

Development and Validation of a Flow-Injection Assay for Dissolution Studies of the Anti-depressant Drug Venlafaxine
Paraskevas D. TZANAVARAS,* Aspasia VERDOUKAS,** and Demetrius G. THEMELIS***
*Quality Control Department, Cosmopharm Ltd., P. O. Box 42, Korinthos 20100, Greece
**Production Department, Cosmopharm Ltd., P. O. Box 42, Korinthos 20100, Greece
***Laboratory of Analytical Chemistry, Department of Chemistry, Aristotelian University of Thessaloniki, 54124 Thessaloniki, Greece
The first flow-injection method has been developed, optimized and validated for the determination of venlafaxine, an antidepressant drug. The method is based on a direct measurement of the absorbance of the analyte in an acidic medium, at 274 nm. Flow-injection parameters, such as sample injection volume and flow rate, were studied and optimized. The proposed method was validated in terms of linearity, repeatability, detection limit, accuracy and selectivity. Linearity was obeyed in the range 30 - 150 mg L-1 of venlafaxine, while the detection limit (1.5 mg L-1) and repeatability (sr < 1.0%, n = 12) were satisfactory. The sampling rate was 30 h-1. The results of dissolution studies of venlafaxine tablets obtained by the proposed method were in good agreement with those by high-performance liquid chromatography.