Optimization of pearl millet-derived bioactive peptide microspheres with double emulsion solvent evaporation technique and its release characterization

Abstract Past decade has noticed significant scientific progress in the area of food-derived bioactive peptides. However, selection of optimum carrier system, to improve release, absorption efficiency and bioavailability of these peptides is essential. Thus, aim of the current study was to develop bioactive peptide-loaded-eudragit S100 microspheres using double emulsion solvent evaporation technique. A central composite experimental design, with two independent variables (peptide and polymer), was used to study the dependent variables (yield, particle size, and entrapment efficiency). Based on response surface methodology, thirteen formulations were developed. Regression model interpretation revealed the significant relationship between considered dependent and independent variables. Optimum formulation with peptide and polymer concentration of 9.00 mg and 58.58 mg, respectively, showed good yield (88.07 %) with particle size (150.21 μm) and promising entrapment efficiency (88.22 %). In vitro release profile of optimized formulation showed maximum peptide release (89 %) during intestinal phase at pH > 6, and followed Zero order and Hixson crowel models of release due to higher regression coefficient (R2) value which indicate the occurrence of diffusion controlled release of peptide. FT-IR study confirmed the presence of peptide in polymer without any interaction. Thus, eudragit S100 microspheres containing bioactive peptide may be an efficient way to protect peptide degradation and control release during GI environment.