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

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.

The present patent investigation aimed to prepare, optimize, and characterize the urealoaded microsponges for efficient topical delivery in vitro.

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.

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.

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.