Mesoporous silica pellets – A promising oral drug delivery system?

Abstract

In this study we investigated the application potential of ordered mesoporous silica SBA-15 powders as an excipient in development of prolonged release pellets for doxycycline.The doxycycline adsorption onto the SBA-15 powders was performed using adsorption from a concentrated solution. The pellets were obtained via wet granulation, extrusion and spheronization method. The pellets were composed of drug-loaded SBA-15, microcrystalline cellulose (Avicel PH 101), ethylcellulose (22 cP) and magnesium stearate. The 5 wt% polyvinylpyrrolidone (PVP K30) ethanolic solution (96% v/v) was used as a binder. The yield, drug content, size analysis, hardness, friability, disintegration time and pharmaceutical availability tests were carried out. The classic doxycycline pellets based on microcrystalline cellulose were prepared and investigated in the same manner for comparative purposes.The SBA-15 powders were characterized by efficient adsorption of doxycycline (103.5 ± 3.1 mg/g equal to 9.4% drug loading). The SBA-15 pellets were successfully obtained in laboratory scale. The prolonged 12 h drug release in phosphate buffer solution (pH = 6.8) was observed for SBA-15 pellets which was 2 times longer compared to drug release profile of microcrystalline cellulose-based pellets. The obtained mesoporous silica pellets may represent a novel solution in the development of prolonged release formulations for water soluble drugs.