Spectrophotometric Determination of Acyclovir and Ribavirin in Their Dosage Forms

Abstract

Abstract Two simple, accurate, and reliable spectrophotometric methods have been developed for the determination of 2 antiviral drugs, acyclovir (ACV) and ribavirin (RBV), in their pharmaceutical formulations. These methods are based on oxidation of the 2 drugs with either cerium (IV) ammonium sulfate (Method A) or potassium persulfate (Method B). The products of oxidation in both methods are coupled with 3-methylbenzothiazolin 2-one hydrazone, producing a deep blue color with a maximum absorption wavelength at 630 nm. In Method A, the absorbanceconcentration plots were linear over the ranges of 550 and 1060 μg/mL with detection limits of 0.18 μg/mL (8 × 107 M) and 0.63 μg/mL (2.58 × 106 M) for ACV and RBV, respectively. In Method B, the ranges were 545 and 2050 μg/mL with detection limits of 0.11 μg/mL (4.88 × 107 M) and 1.40 μg/mL (5.73 × 106 M) for the 2 drugs, respectively. The molar absorptivities were 4.1 × 103 and 3.65 × 103 L/mol/cm in Method A and 5.03 × 103 and 3.97 × 103 L/mol/cm in Method B for the 2 drugs, respectively. The proposed methods were applied successfully for the determination of the 2 drugs in their pharmaceutical formulations. The percentage recoveries standard deviation were 99.57 ± 0.86 and 100.82 ± 0.46 for ACV; 99.41 ± 1.08 and 100.35 ± 1.03 for RBV. The results obtained were compared statistically with those given by official methods and showed no significant differences regarding accuracy and precision.