Purposes: Aims of this study are dissolution enhancement of a poorly water-soluble drug by nano-sized solid dispersion and investigation of machenism of drug release from the solid dispersion. A drug for osteoporosis treatment was used as the model drug in the study. Methods: melting method was used to prepare the solid dispersion. Drug dissolution rate was investigated at pH 1.2 and pH 6.8. Drug crystallinity was studied using differential scanning calorimetric and powder X-ray diffraction. In addition, droplet size and contact angle of drug were determined to elucidate mechanism of drug release. Results: Drug dissolution from the solid dispersion was significantly increased at pH 1.2 and pH 6.8 as compared to pure drug. Drug crystallinity was changed to partially amorphous. Also dissolution enhancement of drug was due to the improved wettability. The droplet size of drug was in the scale of nano-size when solid dispersion was dispersed in dissolution media. Conclusions: nano-sized solid dispersion in this research was a successful preparation to enhance bioavailability of a poorly water-soluble drug by mechanisms of crystal changes, particle size reduction and increase of wet property.
DISSOLUTION OF A POORLY WATER SOLUBLE DRUG, INDOMETHACIN, FROM HYDROXYPROPYLMETHYLCELLULOSE CONTROLLED RELEASE TABLETS
