Comparative Assessment of Amine-Functionalized KIT-5 and KIT-6 Mesoporous Silica as Carriers for Lornoxicam Adsorption and Release

Abstract

In this research, Mesoporous silica KIT-5 and KIT-6 were prepared using template sol–gel method. The synthesized particles were functionalized through post-grafting method with (3-Aminopropyl) trimethoxysilane (APTMS) to form (KIT5-NH₂) and (KIT6-NH₂) as carriers for lornoxicam (LOX) loading and release. The biocompatibility of synthesized materials was investigated by employing MTT assay with the use of normal rat embryo fibroblast cell line (REF). The results showed that, when unmodified KIT-5 and KIT-6 were used, the amount of LOX adsorbed was negligible, with no scientific value. In contrast, the loading efficiency of LOX increased to reach the maximum value of 59.8% and 72.5% in the case of using modified KIT5-NH₂ and KIT6-NH₂, respectively. The loading process was found to follow Langmuir and Temkin isotherms, with a maximum adsorption capacities of 25.87 and 43.23 mg/g for KIT5-NH₂ and KIT6-NH₂, respectively. In addition, the adsorption kinetics of LOX fit very well with a model of pseudo-second-order. The release profile revealed a combination of initial burst release and prolonged sustained release, with the maximum LOX release of 56.43% and 61.95% at pH 7.4 compared to only 39.15% and 46.97% at pH 1.2 for KIT5-NH₂ and KIT6-NH₂, respectively. In addition, The release process followed the Higuchi model with predominant Fickian diffusion. Cytotoxicity tests showed over 90% cell viability, confirming the carriers' biocompatibility and potential for drug delivery.