Encapsulation and Controlled Release of Benzalkonium Chloride - Production of Antimicrobial Cellulose Nonwoven Fabrics for Wound Treatment

Abstract

Encapsulation and controlled release of an active substance is sought-after due to its many applications, were one of them is chronic wound treatment. By having a continuous release of the antimicrobial agent the risk of infection is reduced and the lifetime of the wound dressing will be increased. The aim of this project is to encapsulate Benzyldimethylhexadecylammonium chloride (BAC) into polymeric microspheres to obtain a controlled release rate and then incorporate the microspheres into cellulose nonwoven fabrics. The microspheres are formulated using the internal phase separation via solvent evaporation methodology. Microscopic techniques are used to evaluate size and morphology of the microspheres. The encapsulation efficiency and release rate from the microspheres are evaluated both from microspheres suspensions and microspheres incorporated into fibres using UV-Vis spectroscopy and LC-MS. Based on microscopic imagery does poly(D,L-lactic-co-glycolic acid) (PLGA) formulate microspheres of desired size, morphology and encapsulation efficiency. By adding NaCl to the continuous phase, encapsulation efficiency of BAC was increased along with an increased microsphere size, however long term stability of the microspheres was reduced. Due to BAC’s poor solubility in water containing NaCl, does crystallisation of BAC occur in the continuous phase. Other factors effecting the encapsulation efficiency of BAC was type of solvent used, evaporation method and the amount of BAC added during formulation. Furthermore, incorporation of microspheres into cellulose nonwoven fabrics were successful, and the particles was well dispersed in the fibre. The release of BAC from polymeric microspheres was slow, and it takes approximately 100 hours until a significant release can be seen. This was observed for release studies from both microsphere suspensions and microspheres incorporated into cellulose fabrics. The conclusion is then that a controlled and reduced release of BAC via microencapsulation can be obtained due to the polymeric material acting as a diffusion barrier.