Background and objective: Pharmaceutical formulations for relief of cold signs usually contain high concentration of acetaminophen and small concentration of phenylephrine hydrochloride and chlorpheniramine maleate. The combination makes a problem in simultaneous quantification of the chemicals. Mixture of paracetamol, phenylephrine hydrochloride, chlorpheniramine maleate, and caffeine is commonly used for its analgesic, antipyretic, antihistamine, and antitussive activity. At this study, a simple method based on reversed phase high-performance liquid chromatography was developed and validated for detection of chlorpheniramine maleate, phenylephrine hydrochloride, and paracetamol in pharmaceutical formulations at the same time.
Materials and methods: One ml of stock solutions was diluted with mobile phase to prepare final concentrations of the all three chemicals (20 mg/l of chlorpheniramine maleate, 325 mg/l of phenylephrine hydrochloride, and 50 mg/l of paracetamol). The formulations were prepared by addition of the chemicals to a volumetric flask. Then, they were made up to 100 ml with mobile phase of 0.05 M phosphate buffer:acetonitrile (95:5). pH of the mobile phase was adjusted to 2.5 with 50% orthophosphoric acid. The experiments were done in 250 mm ´ 4.6 mm ´ 5 µm C₁₈ column.
Results and conclusion: Based on the results, flow rate was 1.5 ml/minduring isocratic elution of the samples. The analytes were detected at 210 nm by UV detector. Retention time of the last eluted analyte was 8 min. The method was validated based on ICH guidelines. The results revealed that the proposed method is valid and accurate. Therefore, the validated method can be applied for routine examination of tablets in order to control their quality and stability.