Physical and Chemical Stability Study of Morphine Sulfate Syrup

Abstract

The purpose of this study was to evaluate the physical and chemical stability of morphine sulfate syrup in a concentration of 2 mg/ml, that was prepared by the division of pharmacy, Sappasithiprasong Hospital, Ubon Ratchathani Province. The 2 batches of morphine syrup preparations were kept at 4±1°C, 28±1°C, 37±1°C and 45±1°C, and then the physical and chemical stability were tested initially and periodically for 10 months. The changes in physical characters such as color, odor and particle precipitation were assessed by observation. The pH of the samples was measured by pH meter. The chemical stability of the preparation was evaluated by using HPLC analytical technique. It was found that morphine sulfate syrup stored at 4±1°C, 28±1°C, 37±1°C and 45±1°C were physically and chemically stable regarding color and odor. The pH of the samples were unchanged compared with those of the initial. In addition, all test samples remained free of visible particles throughout the study. The remained drug amounts of samples at 4 storage temperatures were more than 90%. However, the microbiological stability and preservative effectiveness tests should have been included in this study in order to ensure the efficacy and safety of drug use.