Stability‐indicating methods for the determination of a mixture of almitrine and raubasine by derivative spectrophotometry |
| |
Authors: | Mohammad A El‐Sayed |
| |
Institution: | Cairo University, Faculty of Pharmacy, Department of Analytical Chemistry, Kaser El‐Aini Street, ET 11562, Cairo, Egypt |
| |
Abstract: | A second‐derivative spectrophotometric method (2D) and a derivative ratio spectrum zero crossing (1DD) method were used to determine raubasine and almitrine dismesylate in the presence of raubasine degradation product, using methanol as a solvent. Linear relationships were obtained in the range from 6–20 µg ml?1 raubasine for the (2D) method and 12–24 µg ml?1 almitrine dismesylate for the (1DD) method. By applying these methods it was possible to determine raubasine in its pure powdered form with an accuracy of 99.93 ± 1.116 (n = 8) for the (2D) method and almitrine dismesylate with an accuracy of 99.98 ± 0.602 (n = 7) for the (1DD) method. Laboratory‐prepared mixtures containing different ratios of raubasine, almitrine dismesylate and raubasine degradation product were analysed and the proposed methods were valid up to 50% of raubasine degradation product. They were found to be suitable stability‐indicating assay methods for raubasine and almitrine dismesylate in pharmaceutical formulations. Copyright © 2009 John Wiley & Sons, Ltd. |
| |
Keywords: | almitrine dismesylate derivative ratio raubasine zero crossing |
|
|