Effect of β-cyclodextrin and hydroxypropyl β-cyclodextrin complexation on physicochemical properties and antimicrobial activity of cefdinir

The solid-state properties, dissolution profile and antimicrobial activity of inclusion complexes of cefdinir (CEF) with β-cyclodextrin (βCD) and hydroxypropyl β-cyclodextrin (HPβCD) were investigated. The phase solubility profiles of cefdinir with βCD and HPβCD were classified as AL-type, which indicates the formation of 1:1 stoichiometry inclusion complexes. Stability constants with 1:1 molar ratio obtained from the phase solubility diagrams were 120.38 ± 1.07 and 58.60 ± 1.20 M−1 for βCD and HPβCD, respectively. Binary systems of CEF with βCD and HPβCD prepared by kneading method were characterized by Fourier transformation-infrared spectroscopy (FTIR) and X-ray powder diffractometry (XRD). The aqueous solubility of CEF was enhanced by 101% for βCD and 23.4% for HPβCD, respectively. The dissolution profiles of inclusion complexes were determined and compared with those of CEF alone and their physical mixtures. The dissolution rate of CEF was increased by βCD and HPβCD inclusion complexation moderately. However, the antimicrobial activity of CEF was increased significantly (p < 0.001) by βCD and HPβCD inclusion complexation against S. aureus and E. coli. In all these studies, HPβCD had superior antimicrobial activity than that of βCD while βCD had greater effect on solubility enhancement of CEF.