Extractive Spectro Estimation of Clarithromycin and Clindamycin in Bulk and Dosage Forms

Two spectrophotometric methods are described for determination of Clarithromycin and Clindamycin in bulk and pharmaceutical dosage forms using two acidic dyes, bromocresol purple and Bromocresol green to form ion pair extractable complexes with clarithromycin and clindamycin HCl then measuring absorbances at (390nm for clarithromycin or 397 nm for clindamycin) and 413 nm respectively. The effect,s of acidity, buffer volume and dye concentration, on the absorption were studied. Calibration curves were linear over ranges of 12-28 μg.ml-1 for Clarithromycin and 8- 40 μg.ml-1 for Clindamycin in case of bromocresol purple and of 4-20 μg.ml-1 for Clarithromycin and 16-32μg.ml-1 for Clindamycin in case of Bromocresol green. The methods were satisfactory applied for the determination of drugs in both bulk and pharmaceutical dosage forms and results were compared statistically with reference methods.