长效硝酸异山梨醇酯片的体外释放和麻醉猫血压变化的关系

奚念朱等曾报道用海藻酸钙凝胶骨架为缓释材料制成硝酸异山梨醇酯(ISDN)的长效片剂。每片含ISDN 20mg,日服一片在治疗心绞痛方面疗效满意,确有缓释片剂的实用价值。本文就这种长效片的体外释药速度与体内的药理作用强度、持续时间的相关性进行了研究。我们参考Sachchidananda方法以麻醉猫的降压作用作为体内指标。

RELATION OF IN VITRO RELEASE OF THE ISOSORBIDE DINITRATE TO BLOOD PRESSURE CHANGES AFTER ADMINISTRATION TO ANEATHETIZED CATS

The in vitro release of isosorbide dinitrate from a sustained-release tablet was determined by using 0.1N HCl, a simulated gastric fluid for the first 3 hr and phosphate buffer solution pH 7.2～7.4, an simulated intestinal fluid for the subsequent 3 hr. The drug was gradually released and was completely dissolved at the end of 6 hr. When the tablet was introduced directly into the stomach of anesthetized cats, a 63% fall in arterial blood pressure was observed which persisted for more than 10 hr. A good correlation between the rate of the percentage release of the drug in vitro and the in vivo effect in sustained percentage lowering of the blood pressure was obtained. The in vitro method described is proposed for the quality and bioavailability control of isosorbide dinitrate sustained-release tablets.