Background: Microsponges is a class of polymeric microspheres that are porous and are
aimed to deliver a pharmaceutically active constituent competently at the smallest dose and also, to alter
release of the drug.
Objective: The aim of the present work was to formulate a topical gel based drug delivery system of
microsponges containing Celecoxib (CXB).
Method: Quasi emulsion solvent diffusion method was used to prepare microsponges. The inner phase
of formulation (drug dissolved in polymer solution) was added drop-wise into outer phase of Polyvinyl Alcohol (PVA) solution
at room temperature. Microsponges were obtained after stirring for 3 hours. Drug loaded microsponges, dispersed
in propylene glycol, were added to soaked carbopol and mixed thoroughly. Final pH was adjusted by triethanolamine. Final
formulation was evaluated for particle size, % entrapment efficiency, % production yield, surface morphology, % drug
release, drug content, rheological behaviour, in vitro skin permeation etc.
Results: Microsponges of optimized batch were spherical, fine and free flowing. The optimized formulation showed %
practical yield of 72.84 ± 1.34, % entrapment efficiency of 82.4 ± 1.48 and mean particle size of 26.4 m. The optimized
batch incorporated in gel showed pH of 6.1, 12.35 grams-cm/sec of spreadability, 99.06 % of drug content and 68.1 %
drug release. Skin permeation studies concluded that the drug was released in a controlled manner for a period of 12
hours. The optimized batch was found to be appropriately stable.
Conclusion: The CXB loaded in a microsponge based gel was found to have good appearance, other micromeritic properties
and entrapment efficiency along with controlled in vitro release profile of drug.