CONTROLLED RELEASE PROFILES OF CEFEPIME FROM MCM-41-NH2 MATERIALS

The aim of the present study is to evaluate the release profiles of Cefepime,(1) a fourth generation beta-lactamic antibiotic, from MCM-41-NH2 materials. In order to achieve this goal, we synthesized the MCM-41 material for comparison, and we chose a completely new method for its functionalisation using p-aminobenzoic acid. There are many ways(2-4) to anchor amino groups onto the MCM-41 surface, but amongst these, aminopropylsilanes seem to be the method of choice in all scientific articles. However, for oral intake, aminopropylsilanes pose a serious threat due to their toxic nature and higher reactivity. We considered replacing those materials with a less toxic functionalization reagent, the p-aminobenzoic acid (vitamin Bx). This approach is both unique and innovative and can be a direction to follow in the functionalization of silica surfaces, mainly due to the toxicity of the amino-silane reagents and the availability of the p-aminobenzoic acid. The Cefepime loading was done from ethanol solution, ensuring thus the procedure's lack of toxicity. This technique has the advantage of a good antibiotic's diffusion in the porous system of the MCM material, and that all the quantity of the antibiotic is delivered to the system with no losses. For the release profiles we used a modified HPLC system, the UV detector of this system providing more accurate readings and a continuous monitoring of the release profile. The functionalization of the active surface with -NH2 groups proinotes a slower and more stable release, which can be associated with the stronger binding between those groups and the beta-lactamic antibiotic than in the case of unmodified MCM-41. We achieved this goal in a less toxic approach, by an original method, and with very satisfactory results. This effect can be variously exploited, either in oral intake drug delivery systems, or in other forms of drug delivery systems, like wound dressing materials.