Development and Characterization of Polymeric Microsponge as a New Vehicle to Deliver Urea Topically

Background: Topical delivery of therapeutic agents is considered beneficial due to various advantages like ease of administration, avoidance of the first-pass effect, and improved patient compliance. Therefore, scientists around the globe are exploring this route for the delivery of drugs nowadays. Objective: The present patent investigation aimed to prepare, optimize, and characterize the urealoaded microsponges for efficient topical delivery in vitro. Methods: Urea-loaded ethylcellulose microsponges were prepared using quasi emulsion solvent diffusion technique and optimized using Box–Behnken design (BBD). Furthermore, they were characterized in-vitro using various techniques like scanning electron microscopy (SEM), differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FT-IR), and X-ray diffraction analysis (XRD). In-vitro drug release and release kinetics analysis was also performed. Results: Urea-loaded microsponges were spherical and porous. Optimized urea loaded microsponges showed a minimum size (39.78 ± 1.98 μm), high entrapment (74.56 ± 2.8%), acceptable polydispersity index (PDI) (0.224 ± 0.081) and zeta potential (-21.9 ± 2.9 mV). These microsponges were capable of sustaining the release of urea for 24 h (91.21 ± 5.20%), and the mechanism of release was the combination of diffusion and erosion. Conclusion: The developed microsponge system could be beneficial for topical delivery of urea as it could reduce the dosing frequency of urea and increase patient compliance through its sustained release.