Inclusion of cefalexin in SBA-15 mesoporus material and release property

Abstract

SBA-15 (Santa Barbara Amorphous-15) is a high ordered mesoporous material. It has the advantages of a non-toxic property, good hydrothermal stability and thermal stability, etc. Inside inner surface a lot of silanols exist. Pore diameter size is uniform and pore size distribution is narrow. This structural feature makes SBA-15 have a higher loading drug amount and be able to effectively extend the drug release cycle. In this paper, polyethylene glycol-block-polypropylene glycol-block-polyethylene glycol was used as template and tetraethyl orthosilicate was used as silica source to prepare SBA-15 by hydrothermal synthesis method. Cefalexin was included in SBA-15 and the included cefalexin drug content was 158.72mg/g. The composite materials were characterized by using chemical analysis, powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), infrared (IR) spectroscopy, and low temperature nitrogen adsorption–desorption. The results showed that cefalexin had been successfully included in host SBA-15 pore channels. Rational analyses of the release processes of cefalexin drug from the pores of SBA-15 to the simulated body fluid, simulated gastric juice and simulated intestinal fluid were made and sustained-release effects of the drug in complex system were studied. The results showed that in simulated body fluid within 1–5h cefalexin was fast released and the cumulative release reached 50.00% at 5h. In 15–20h, the sustained release speed of cefalexin drug in the composite material decreased and the sustained-release cumulative amount reached 99.87% at 20h. The release of cefalexin was basically complete. In simulated gastric fluid, composite material sustained-release ended at 4h, the cumulative sustained release ratio reaching 26.10%. In simulated gastric fluid, the sustained-release was complete at 7h, the cumulative sustained release ratio reaching 32.46%. The composite material of SBA-15 and cefalexin could improve efficiency of the sustained-release of drug and has a very great potential applicable value.