Effect of copolymers in improving the properties of cefpodoxime proxetil using solid dispersion

Abstract

The aim of this research is to study the effect of copolymers in increasing the solubility and dissolution rate of antibiotic cefpodoxime proxetil (poorly water-soluble drug) by formulating it with water-soluble polymer poloxamer 188 using solid dispersion (SDs) technique, kneading method (KM), and Physical mixture (PM) were employed to prepare the dispersion in three different ratios (drug (cefpodoximae proxetil): polymer (poloxamer 188) 1:1, 1:2 and 1:3). The physical mixture, and solid dispersion(s) were characterized by several methods such as: drug content, dissolution rate study, saturation solubility, differential scanning calorimetry (DSC), FT-IR spectroscopy and density test. The results showed that the solid dispersion was able to increase the rate of dissolution significantly, as the release rate reached 91% in the solid dispersion with a ratio of (1:3) after 60 minutes, while the release rate of the antibiotic alone was 27% after the same time period. The enhancement of dissolution rate may be caused by increase wettability, dispersibility or reduction in particle size of drug. The FT-IR study revealed that there was no chemical interaction between drug and polymer. The DSC study showed the disappearance of an endothermic peak in SDs which can be attributed to inclusion of drug in the polymer and formation of amorphous form.