determination of aciclovir and its related substance guanine in bulk drug and tablet preparation by capillary electrophoresis

two capillary zone electrophoresis (cze) methods were developed in this study, one using an acidic buffer (sodium citrate ph = 2.5) and the other using a basic buffer (sodium tetraborate ph = 9.8). the two methods were compared on the basis of repeatability and reproducibility of results and the cze method developed with the basic buffer was then selected for further studies. the method was fully validated in terms of repeatability [rsd for migration time and peak area of aciclovir at 0.05 mg (nominal concentration) were 0.3-1.0% (x=10), and 1.5-2.6% (n=3), respectively], reproducibility (rsd of peak area = 2.54%, n = 6), linearity over two ranges of aciclovir concentration (0.01-0.07 and 0.05-0.3 mg/ml which resulted in y=2.007x +1.300 and y=0.234x + 0.82, respectively) , limits of detection and quantitation (1´ 10-4 mg/ml and 3´ 10-4 mg/ml, respectively), ruggedness and robustness. the method was applied for the determination of the drug in a commercial tablet preparation (mean recovery value 100.2% w/w) and a commercial injection solution. the method proved to be fast and reliable for quantitative analysis of aciclovir and its related substance in bulk and pharmaceutical dosage forms.