DEVELOPMENT OF BIOPLASTIC IN-SITU IMPLANT FOR ANTIBIOTIC DRUG LOADING

Typically, solvent removal-induced in-situ implants start in a solution state and undergo phase inversion to form depot formulations. In this research, the development and evaluation of a bioplastic in-situ implant for antibiotic drug loading were conducted. Two types of cellulose acetate butyrate (CAB) and cellulose acetate propionate (CAP) were used as bioplastic polymers for the in-situ implant. These polymers, at a concentration of 15% w/w, were dissolved in various solvents, including dimethyl sulfoxide (DMSO), glycerol formal (GF), N-methyl pyrrolidone (NMP), 2-pyrrolidone (PYR), and tetraglycol (TG). The polymers did not completely dissolve in TG, whereas all the other solvents were able to dissolve the polymers fully. Notably, the lowest apparent viscosity of these polymeric solutions was achieved when NMP was used as the solvent. The in-situ implants loaded with 1% w/w levofloxacin hemihydrate (Lv) were prepared using these polymers dissolved in NMP. The low viscosity of these solutions, combined with their rapid transformation into a depot matrix, facilitates administration via injection. The use of CAP as a polymer in this drug delivery system enabled self-transformation into a matrix in an aqueous medium due to solvent removal. Nonetheless, its depot hardness and adhesion were slightly lower than some in-situ implant prepared from CAB. Microscopic observations under both stereoscope and microscope confirmed swift phase inversion into a matrix implant of the Lv-loaded CAP-based in-situ implant after exposure to aqueous phase of agarose gel. This implant prolonged the release of the antibiotic drug for five days. Additionally, the developed in-situ implant demonstrated effective antimicrobial activity against Phophyromonas gingivalis, Staphylococcus aureus and Candida albicans. These findings highlight the potential of Lv-loaded CAP-based in-situ implant systems as promising candidates for localized depot delivery systems, particularly after exposure to physiological fluids such as crevicular fluid for the treatment of periodontitis.