盐酸维拉帕米缓释微球含量的测定及体外释放行为研究

Determination and in vitro release behaviors of verapamil hydrochloride surstained-release microspheres

目的建立UV法测定盐酸维拉帕米缓释微球含量的方法,考察环境pH对微球释药行为的影响。方法采用UV法测定缓释微球中盐酸维拉帕米,对该方法的专属性、精密度、回收率、稳定性等进行考察;并测定维拉帕米微球在蒸馏水、0.1 mol L-1盐酸、pH=6.8磷酸盐缓冲液3种不同的释放介质中的累积释放度,采用f2相似因子法对不同释放介质药物释放曲线的相似性进行评价。结果不同介质中的盐酸维拉帕米在229 nm处,吸光度A值和浓度C间线性关系均良好,线性范围为7.5～22.5μg mL-1,r值为0.999 9,平均回收率的RSD值均<2%。结论该方法操作简便快捷,结果准确可靠,可用于盐酸维拉帕米缓释微球的含量测定,缓释微球在蒸馏水、pH=6.8磷酸盐缓冲液中的累积释放度基本一致,在0.1 mol L-1盐酸中释放较快。

Abstract： Objective To determine the content of surstained-release of verapamil hydroch-loride microspheres by the UV method and to investigate the influence of release behaviors of drug microspheres under pH condition. Methods We used UV method to determine the surstained-release microspheres of verapamil hydrochloride, and to investigate the specificity, precision, recovery and stability of the method. The accumulation release of verapamil microspheres was measured by 3 dissolution media, namely distilled water, 0.1 mol·L^-1 hydrochlorie acid, and pH = 6.8 phosphate buffer. With the method of similar factor f2, the similarity of the curve of different dissolution drugs was evaluated. Results At 229 nm, the linear relationship of absorbance A and concentration C of the verapamil hydrochloride in different media were fine. The linear range was 7.5 - 22.5 μg· mL ^-1, r 0.999 9 and average recovery RSD value was less than 2%. Conclusion This method is fast, simple, accurate and reliable, which can be used to determine the content of controlled release microspheres in verapamil hydrochloride. The accumulation of surstained-release microspheres in distilled water and pH = 6.8 phosphate buffer is consistent while it goes a little faster in 0.1 mol·L^-1 hydrochloric acid.