ABSTRACT:
Naproxen is a nonsteroidal anti-inflammatory drug (NSAID) used for treatment of fever and inflammation. It is mostly available as tablet dosage form. Hospital pharmacists always prepare the drug in an orally liquid preparation such as suspension for pediatric use. To determine the amount of naproxen in an extemporaneous preparation and during stability studies, a HPLC method was developed and validated by following the Asean guideline for validation of the analytical procedure. The method used a C18 column as the stationary phase whereas the mobile phase was a mixture of 50 mM sodium phosphate buffer pH 7.8 and acetronitrile (70:30). The flow rate was 0.7 ml/min and injection volume was 20 µl. The drug was measured at 230 nm. The result showed that the retention time of naproxen was about 8.18 min, and the method was specific to the drug in the presence of other common excipients in the preparation. It was accurate (97.45 ± 0.63%) and precise (1.33-2.33% RSD). It was linear in the concentration range of 2.56 ng/ml- 50 µg/ml (R2= 0.9999). The limit of detection (LOD) and limit of quantification (LOQ) were 0.19 and 0.59 µg/ml, respectively. Minor changes of flow rate, mobile phase composition, wavelength and injection volume slightly affected the drug analysis. Forced degradation studies (hydrolysis, oxidation and temperature) showed that the method was served as a stability-indicating procedure. It demonstrated that the validated method was simple, reliable, accurate and robust to determine naproxen in the extemporaneous suspension. In addition, it could use for analysis of the drug in the stability studies.