Pharmaceutica Analytica Acta

Abstract

Spectroscopic Studies and Applications of the Reactions of Some Anti-Diabetic and Anti- Hypertensive Drugs with Rose Bengal

Zayed MA and Farrag YS

Simple, rapid and sensitive spectrophotometric methods were developed and validated for the microdetermination of terazosin HCl, doxazosin mesylate and pioglitazone HCl drugs in pure and pharmaceutical dosage forms. These methods are based on ion-pair formation reaction between these drugs and a chromogenic reagent Rose Bengal (RBeng). These reactions were studied under various conditions and the optimum parameters were selected. The spectrophotometric microdeterminations have been done at λmax=570 nm for terazosin HCl and pioglitazone HCl and at λmax=575 nm for doxazosin mesylate. Under proper conditions the suggested procedures were successfully applied for microdetermination of these drugs in pure and in pharmaceutical dosage forms. The values of SD, RSD, recovery %, LOD, LOQ and Sandell sensitivity refer to the high accuracy and precession of the applied procedures. The results obtained were compared with the data obtained by the official methods, referring to confidence and agreement with rose bengal procedure results. The solid drugs-reagent ion-pairs were prepared, separated and their structures were investigated using elemental analysis, FT-IR, 1H-NMR and thermal analyses and the results confirm the structures proposed by the stoichoimetric ratio in the solution work. The biological activities of the drugs and their solid ion-pairs against some types of (G-) and (G+) bacteria and fungai were studied and compared with each other. It is found that terazosin-RBeng and pioglitazone-RBeng reaction products have antibacterial effect higher than the parent drugs, but doxazosin-RBeng reaction product has almost the same antibacterial effect of the parent drug.