Development of chloramphenicol whey protein-based microparticles incorporated into thermoresponsive in situ hydrogels for improved wound healing treatment.

This study focused on the incorporation ofchloramphenicol (CAP)intowhey protein (WPI)(CAP-MPs) and was further formulated into a thermoresponsivein situgel for wound healing treatment.CAP microparticleswereproduced by two steps emulsification process.The modification ofthe mixing time and speed, as well as the variation of WPI and CAP concentration, resulted in various particle sizes(0.95 ± 0.07to 8.94 ± 0.32 μm). The optimum formulation was achieved using 15 % WPI in water, and 2 mL CAP in propylene glycol withatotal amount in the mixture was 100 mg, and 5 % oil phase, with homogenization time and speed at 15 min and 7500 rpm, respectively. The characterization of CAP-MP's showed PDI values at 0.110 ± 0.007, drug entrapment efficiency at70.64 ± 1.12 %,and drug loading at 8.80 ± 0.12 %.SEM analysis of CAP-MPs showedspherical, uniform particlesdispersed across the surface of the emulsion droplets.FTIR analysis showed strong development of hydrogen bonds proving the encapsulation was effective. Pluronic® F127, Pluronic® F68, and hydroxypropyl methylcellulose (HPMC)were used for the thermoresponsive hydrogel formulation with desired properties. The gel formulationcouldprovideliquid form at room temperature (25 °C) andformagel at 31 °C.This optimum formula was able to increase the bioadhesivity (28160.92 ± 3902.09 dyne/cm) as well as the percentage of gels skin occlusivity after 24 h (32.82 ± 0.004),and to be considered, it did not show hemolytic activities. In anex vivoantibacterial activity, this combination approach showed a 99.95 % reduction in theStaphylococcus aureus(SA) population.