Abstract

Objective: The aim of this study was to validate a high-performance liquid chromatographic (HPLC) method for analysis of sildenafil citrate in an extemporaneous preparation, according to ASEAN guideline for the validation of analytical procedure. Methods: The chromatographic condition used a C18 column with a mobile phase consisted of 50% 0.2 M ammonium acetate buffer pH 7.0 and 50% acetonitrile. The flow rate was performed at 1.0 mL/min, and UV detection was monitored at 245 nm. Results: It was shown that the retention time of sildenafil was about 8.80 min. The analytical method used was specific to sildenafil in the presence of other common excipients in the preparation. The method was accurate (100.18% recovery), precise (< 2% RSD), and robust. Linear correlation was obtained over a concentration range of 0.01 - 60.00 μg/mL (r²= 0.9999). Limit of detection (LOD) and limit of quantification (LOQ) were 3.82 and 11.57 ng/mL. respectively. Forced degradation showed that the method would serve as a stability-indicating procedure that applied for the analysis of the drug in the stability studies. Conclusion: The proposed method met the general requirements with an acceptable performance for validation. It was accurate and reliable, and served as a stability-indicating method. Therefore, it can be used to determine sildenafil citrate in the extemporaneous suspension preparation.