Document Abstract
A simple and sensitive solid phase extractive spectrophotometric method for the determination of three sulfa drugs in bulk, in pharmaceutical dosage forms and in biological fluids was developed. The method is based upon coupling of diazotized sulfa drug with phloroglucinol in an acidic medium. The resulting yellow dye has absorption maximum at 420nm and the resulting dye is stable for several days. The Beer’s law range for sulfamethoxazole, sulfacetamide and sulfadiazine in aqueous medium are 0.2-2.0, 0.2-2.0 and 0.1-1.0 μg mL-1 respectively and in extractive medium range for above drugs are 0.02-0.2, 0.02-0.2, and 0.01-0.1 μg mL-1. The molar absorptivity for the sulfa drugs is 9.21x 105, 7.79 x 105 and 1.820 x106 L mol-1 cm-1 respectively. The developed method is free from the interference of common excipients used in pharmaceutical dosage. The method was also used for the determination of sulfa drugs in pharmaceutical dosage as well as in human serum and urine samples.
Keywords: Sulfamethoxazole, sulfacetamide, sulfadiazine, phloroglucinol, spectrophotometry. Solid phase extraction