Inclusion complex of prednisolone with skimmed milk. Part I: Physicochemical characterization.

Prednisolone is a safe antiinflammatory agent for the treatment of inflammatory diseases. To improve the aqueous solubility of the drug and dissolution rate, the complexation of prednisolone with skimmed milk was studied. A physical mixture and solid dispersion of prednisolone with skimmed milk were prepared. The lyophilization method was used to prepare the solid dispersion. Detection of inclusion complexes was performed in the solid state using differential scanning calorimetry (DSC), powder X-ray diffractometry, and scanning electron microscopy. The diffractogram of the complex differed from that of the physical mixture, where the characteristic peaks of prednisolone, particularly at 23.9 degrees, 44.6 degrees, and 72.2 degrees (2 theta), nearly disappeared, indicating the formation of a true inclusion complex. These observations were in accordance with the results of the DSC analysis. Disappearance of the specific DSC peaks of the drug in the DSC curve of the solid dispersion showed that the drug interacts with the carrier.