Microencapsulation of a slightly soluble drug by surface neutralization method using an enteric polymer.

Succeeding our previous study on enteric microencapsulation by surface neutralization method for acidic drugs, a new means of application was developed for the encapsulation of non-acidic drugs. Indomethacin was chosen as a model drug in this study because of its low solubility in water and non-acidicity. Carboxylmethylethylcellulose was used as enteric polymer as previously. Indomethacin was not encapsulated as it was, but the encapsulation could be done using its core granules added with an organic acid. Thus, the influences of preparation temperature, species of organic acid and its concentration in the cores as well as the species of binder on the properties of resultant microcapsules were examined