ABSTRACT
Objective To establish the HPLC method of assay for diphenhydramine hydrochloride in compound diphenhydramine cream. Method HPLC analysis was carried on ACE5C18S/N-A66766 column (150 mm×4.6 mm, 5 µm) with the mobile phase of methanol-water-triethylamine (70:30:0.67, adjusting pH to 6.50 with phosphoric acid) at room temperature. The detection wavelength was set at 230 nm and the flow rate was 1.0 ml/min. The analyte was extracted from the cream and 20 μl of sample was injected. Results The calibration curve of diphenhydramine hydrochloride was linear in the range of 39.52-197.6 µg/ml (r=0.999 7). The average recovery of diphenhydramine hydrochloride was 100.5% (RSD=1.25%, n=9). The repeatability of the method was expressed using RSD with 0.78% (n=6). The results of assay were 101.3%, 99.83% and 99.62%. Conclusion The method is accurate, sensitive, selective and repeatable, which can be applied for improving the quality standard of compound diphenhydramine cream.
ABSTRACT
Objective To optimize the manufacture process for Zhibai Anshen oral liquid. Methods The orthogonal designed experiments were conducted to monitor the effects of three factors on the content of mangiferin. The three factors included the amount of water, extraction time and alcohol precipitation concentration. Six month accelerated stability study and twelve month long term stability study were performed. Results Optimum percolation process was boiling the mixture with 10 times of water for 1 hour, followed by deposition with 60% alcohol. Conclusion This optimized process can be used for mass production.