| Summary: | 碩士 === 國立臺灣大學 === 藥學研究所 === 96 === Lansoprazole is a proton pump inhibitor which selectively inhibits H+/K+-ATPase. It is usually used for gastric ulcer diseases. However, due to its short half life in plasma, lansoprazole cannot control nocturnal acid breakthrough. This study was aimed to improve this situation by preparing sustained-release lansoprazole microparticles.
In this study, the RS-100 sustained release microparticles were made by the oil/water solvent evaporation method. Three responses (homogenization rate, concentration of Eudragit®® RS-100 and Eudragit®® RS-100/lansoprazole ratio) that would affect the sustained release microparticles were further evaluated. By using the oil/water solvent method, the RS-100 sustained release micorparticles were covered with the second layer enteric coating. The content of the Mg stearate and the ratio of the Eudragit®® L100-55/RS-100 microparticles were also discussed.
The result showed that increasing homogenization rate would decrease particle size, encapsulation efficiency and yield of RS-100 sustained release microparticles. Increasing concentration of Eudragit®® RS-100 would increase particle size, encapsulation efficiency, drug loading and yield. Increasing Eudragit®® RS-100/lansoprazole ratio would increase encapsulation efficiency and yield; for drug loading, the ratio 10/10 was equal to 10/5 and both larger than 10/1. The SEM micrographs showed the sustained release microparticles with good spherical shape. Based on FT-IR and DSC data, lansoprazole was physically wrapped by Eudragit®® RS-100 as non-crystal form. In vitro release showed that reduction of homogenization rate or increased in concentration of Eudragit®® RS-100, decreased release rate of lansoprazole. Increasing Eudragit®® RS-100/lansoprazole ratio would increase release rate, but R2000-1010 was faster than R2000-1005.
In the study of enteric coated microparticles, adding Mg stearate would increase particle size and yield, but did not affect the encapsulation efficiency and drug loading; however, the surface of double coated microparticles became rough based on SEM micrographs. While increasing the ratio of Eudragit® L100-55/RS-100 microparticles, increased particle size and decreased drug loading, but did not affect the yield and encapsulation efficiency. According to in vitro release study, some lansoprazole was released from sustained release microparticles during the process of double coating, causing increase of release rate and cumulative release amount of drug from enteric coated microparticles.
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