簡易懸濁法を用いたモルヒネ塩酸塩錠投与法の検討

Abstract

Only two dosage forms, 5 and 10 mg/pack, are commercially available for immediate-release morphine solutions. For this reason, patients requiring high dose morphine use a pack quickly, while suffering from breakthrough pain. In Nagoya University Hospital, we prepared high-concentration morphine aqueous solution for these patients by dissolving morphine hydrochloride powder. However, the maximum prescription period of this solution is set to 14 days by the internal rules of the pharmacy because it contains no antiseptic. Therefore, the patients must visit the hospital every 14 days to obtain the prescription. Whereas the maximum prescription period of morphine hydrochloride tablets is 30 days. Thus, the frequency of patient visits can be reduced by half if the patients themselves can prepare morphine solution from morphine tablets by a simple suspension method. Therefore, we examined the disintegration of morphine tablets by a simple suspension method, and the stability of morphine in the suspension. Initially, 5 or 20 tablets of “10-mg morphine tablet” were added to 20 mL of tap water at 55 °C, and disintegration of the tablets was macroscopically checked. Tablets were completely disintegrated in 5 minutes and in 10 minutes, respectively. Next, to evaluate the stability of morphine in the suspension, morphine concentration was measured by high-performance liquid chromatography until 28 days after suspending the tablets. The residual rate of morphine in the suspension was between 96.7% and 104.8%. These results suggest that morphine solution can be prepared from the tablets using a simple suspension method.