Formulation and optimization of budesonide-loaded dry emulsion for colon targeted drug delivery

Abstract

Budesonide is an effective glucocorticoid used in the management of inflammatory bowel disease;
however, its clinical performance is restricted by extensive first-pass metabolism and low systemic
bioavailability. To address these challenges, a colon-targeted dry emulsion system was successfully
developed using a lipid-based oil-in-water emulsion that was converted into a free-flowing dry powder
with suitable carriers. This formulation approach improved stability, ease of handling, storage, and
reconstitution characteristics.
Pre-formulation investigations, including solubility and drug- excipient compatibility studies,
confirmed the compatibility of the selected ingredients. Formulations F1- F10 showed progressive
enhancement in physicochemical properties with increasing concentrations of oil, surfactant, and
polymer. Particle size was reduced from 320 nm to 195 nm, while PDI values decreased from 0.45 to
0.20 and zeta potential increased from −18 mV to −40 mV, indicating improved stability and particle
uniformity.
Drug content ranged between 92% and 99%, whereas entrapment efficiency increased from 70% to
93%. Drug release improved from 65% to 90%, demonstrating efficient colon-targeted release. Flow
properties were also enhanced, as indicated by the reduction in angle of repose from 34.5° to 24.5°.
SEM analysis revealed smooth, spherical, and uniformly distributed particles in optimized formulations.
Stability studies demonstrated only minor changes after storage, with optimized batch F10 maintaining
excellent stability. These findings suggest that the developed dry emulsion system is a promising
strategy for effective colon-targeted delivery of Budesonide.