Development and Validation of Spectrophotometric Methods for the estimation of Gemcitabine in Bulk Drug and its Pharmaceutical Formulations.

Three simple, precise and sensitive visible spectrophotometric methods (A, B and C) have been developed and validated for the quantitative estimation of Gemcitabine in bulk drug and its pharmaceutical formulations. Method A is based on Diazotization followed by coupling of Bratton Marshall Reagent (BMR) with Gemcitabine to form red colored chromogen, which exhibits absorption maxima at 554nm and obeys Beer's law in the concentration range of 50–250μg/ml. Method B and C is based on ion pair formation between the drug and two acidic dyes, namely Bromocresol green(BCG) and Bromocresol purple (BCP), which were measured at 418 and 413nm respectively and Beer's law obey's in the concentration range of 20–100μg/ml and 50–250μg/ml respectively. The results of the proposed methods were validated statistically, recovery studies and are compared with those obtained by the UV method. The proposed methods were applied successfully to the determination of gemcitabine in commercial dosage forms.