Use of Differential Spectrophotometry for Determination of Cytarabine and Acyclovir in Their Dosage Forms

Abstract Differential (ΔA), first derivative- (ΔD1) and second derivative- (ΔD2) differential ultraviolet spectrophotometric methods have been presented for the quantitation of cytarabine and acyclovir in their pharmaceutical formulations such as injections and creams. The methods are based on measuring ΔA, ΔD1 and ΔD2 of the active ingredients in acidic solutions against their basic solutions as blanks. The proposed methods are sensitive, highly specific and advantageous over the conventional UV assays since all interferences of the excipients or irrelevant absorptions are nullified. Accuracy of the analysis with the proposed procedures is significantly greater than the classical spectrophotometry methods.