Effect of Trimethoprim Inclusion Complexation with Cyclodextrins on its Antimicrobial Activity

The aim of present study is to highlight the effects of β-cyclodextrin (BCD) and hydroxypropyl-β-cyclodextrin (HBCD) and also the effect of their concentrations and methods of inclusion complexation on solubility and antibacterial activity of trimethoprim [TMP] by inclusion complex formation. The inclusion complexes of TMP were prepared by solvent evaporation, spray drying, kneading and physical mixture methods in 1:1 and 1:2 ratios. The inclusion complexes were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), dissolution study and antimicrobial activity by disk diffusion method. Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) results proved formation of inclusion complex of TEM with cyclodextrins. XRD showed decrease in crystanality of TEM after complexation with CDs. The results of saturation solubility study and release study prevailed the more increase in solubility of TMP by HPCD than BCD. The antibacterial activity of TMP was found to be increased with the complexation process. An increase in concentration of CD increased the dissolution and the antibacterial activity.