Loading and Controlled Release of Poorly Water-Soluble Drug Telmisartan from Porous Silicon Microparticles

Objective To prepare porous silicon microparticles by electrochemical etching process and study telmisartan loading and release kinetics to develop controlled drug delivery system. Method A 50 mA/cm 2 of current density was applied for 180 s in HF:ethanol (2:4) solution for the etching of silicon wafer. The silicon film was fractured by probe sonication at 20 kHz of frequency and 750 W powers for 120 s to make the micro-sized particles. Drug-loading was carried out by taking 1 M sodium hydroxides solution and in vitro release of telmisartan was investigated using various models, such as zero order, first order, Hixson Crowell, Korsmeyer-Peppas, and Higuchi diffusion model. Results A telmisartan loaded native porous silicon microparticles (TEL-PSi) allowed a very high drug loading up to 58.39 micrograms as compared to telmisartan loaded thermally oxidized porous silicon (TEL-TOPSi) (28.14 micrograms). TEL-TOPSi showed controlled release as compare to TEL-PSi. The release rate of TEL-TOPSi and TEL-PSi was 47% and 77% after 5 h respectively. The Korsmeyer-Peppas model was selected based on its excellent fitting to the release data among all models and indicates diffusion-based release. Conclusion Telmisartan loading and its release kinetics was studied successfully on porous silicon micro particles. TEL-TOPSi micro particles can be used for controlled drug delivery system for poorly water-soluble active pharmaceutical ingredients.