Synthesis and characterization of chlorhexidine acetate drug-montmorillonite intercalates for antibacterial applications

In this study, a drug intercalated montmorillonite (Mt) has been prepared which can be useful in designing novel topical drug delivery system. The drug-Mt intercalates were synthesized by ion exchange route where interlayer cations i.e., K+, Na+ etc. of Na+-Mt exchange with the cation of the drug, chlorhexidine acetate (Ca++). The characterization of drug-Mt intercalates has been done using X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric technique and energy dispersive X-ray analysis; all of which indicate successful intercalation of drug into the interlayer space. These drug-Mt intercalates strongly inhibited the growth of a wide range of microorganisms including both Staphylococcus aureus and Escherichia coli. In vitro release study of the antibacterial drug-Mt intercalates in phosphate buffer saline (pH 7.4) media at 37 °C was investigated. The pattern was found to be initially burst release followed by sustained release. The Ca++-Mt intercalates with a wide range of bioactivity against microbes and controlled release characteristics have the potential for application in the area of topical drug delivery.