Novel modified release tableted microspheres of ibuprofen and misoprostol in a combined formulation: Use of software DDSolver

The current study was aimed to develop a stable sustained release drug delivery system for ibuprofen and a cytoprotective agent misoprostol in a combined dosage form. Non-aqueous emulsion solvent evaporation method was used to prepare ibuprofen microspheres. Ethylcellulose (EC) and Hydroxypropyl methylcellulose (HPMC) were used as the release retarding polymers in combination. Ibuprofen microspheres were prepared separately and then compressed into tablet dosage forms with misoprostol dispersions in HPMC. For surface topography of microspheres, Scanning Electron Microscope (SEM) was used. Fourier transformed infrared (FTIR) spectroscopy and X-ray diffractometry (XRD) were employed to evaluate pharmaceutical incompatibility and physical state of drug in formulation. The mechanism and pattern of drug release were determined by applying kinetic models. Tableted microspheres were also assessed for accelerated stability study for three months. SEM showed spherical shape microspheres. FTIR and XRD data for developed formulation indicated stability and compatibility of drugs with excipients. After 10 h, 86.97 and 89.33% of ibuprofen and misoprostol were released from micro particles while 75.43 and 77.65% from tableted microspheres, respectively. Non-aqueous emulsion solvent evaporation was found to be a suitable method to prepare stable sustained release tableted microspheres of ibuprofen and misoprostol in combination.   Key words: Ibuprofen, misoprostol, hydroxypropyl methylcellulose (HPMC), ethylcellulose (EC), tableted microspheres, DDSolver®.