Comparative study of solubility enhancement of rifapentine by solid dispersion and inclusion complex

Abstract

Solubility enhancement of poorly aqueous soluble drugs is an important aspect of formulation development. The objective of the study was to compare the aqueous solubility and dissolution characteristics of rifapentine enhanced by solid dispersion and inclusion complex technique. The inclusion complex with Hydroxypropyl-ß-cyclodextrin (HPß-CD) and ß-cyclodextrin (ß-CD) have been prepared by different methods in different ratios and found that the kneading method (AK1) shows the better enhancement of solubility in comparison to the solvent evaporation and physical mixing method. The solid dispersion with polyethylene glycol (PEG) 4000 and Mannitol have been prepared by different methods in different ratios and found that solvent evaporation (CS₄) shows the better enhancement of solubility in comparison to the kneading and physical mixture method. As both methodologies are compared, it was observed that, inclusion complex method was found to be the best because it caused significant improvement in dissolution profile (99.23±0.25). The drug content (99.5±0.13) and % inclusion yield (99.6%) was also highest with the kneading method (AK₁ ). The characterization (FTIR and SEM) of the complexes shows that the drug shows amorphous form in the complexes. Amorphous form has higher dissolution efficiency than the crystalline drug. Infrared (IR) Spectroscopy and Scanning electron microscopy were performed to identify any physicochemical interaction between the drug and the carrier and its effect on dissolution behavior.