Study on the properties of capsule shell prepared by multi-type HPMC mixed system

The objective of this study is to develop a viable formulation strategy aimed at minimizing the gel content in HPMC capsules and avoiding the issue of variable drug release rates in the different media environments attributed to the excessive gel content within the capsules. Through mixing various types of HPMC with different gel temperatures, the formulation facilitates reaching the staged gelation upon the mold as the temperature decreases, which effectively reduces the requisite amount of gelling agent. Consequently, the decrease in gel agent content ensures that the dissolution of the capsule shell is unaffected by the pH of the medium and the type of ions in the medium. This property allows for uniform drug release rates across diverse media, with complete drug release occurring within approximately 20 min. This improved formula not only reduces the gelling agent content in conventional HPMC formulations but also is characterized by the absence of any organic solvents and the simplicity of operation, thus providing a dependable and widely applicable method for the synthesis of HPMC capsules.