Biphasic floating minitablets of cefuroxime axetil were prepared by melt granulation technique using two different grades of gelucire namely 50/13 and 43/01 to maintain constant plasma drug concentration. Loading dose of cefuroxime axetil was formulated as immediate release (IR) minitablets by using hydrophilic grade of gelucire 50/13. Maintenance dose was formulated as floating sustained release (SR) minitablets by using hydrophobic grade of gelucire 43/01. The prepared IR and SR granules were subjected to micromeritic studies and scanning electron microscopy. Fourier transform infrared spectroscopy (FT-IR) study revealed that drug and selected carriers were compatible. In vitro dissolution study of optimized IR minitablets showed more than 85% of loading dose dissolved within 30 min. Optimized SR minitablets showed zero lag time with floating duration more than 12 h. The drug release from SR minitablets was linear with square root of time with non-Fickian diffusion-controlled release. The optimized batch of minitablets was filled into 0 size hard gelatin capsule. In vitro dissolution study for capsule showed an immediate burst release followed by SR up to 12 h. There is no significant change in dissolution data after storage at 40 °C and 75% RH for three months. Microbiological assay of dissolution samples of optimized minitablets filled in capsules showed proportionate increase in inhibition of growth against Escherichia coli up to 12 h samples. In vivo bioavailability study in albino rabbits showed three times improvement in oral bioavailability.
Keywords: Bioavailability; cefuroxime axetil; floating minitablets; microbiological assay; pharmacokinetics.