eng Oriental Scientific Publishing Company Biomedical and Pharmacology Journal 0974-6242 2015-01-20 1 1 131 138 264 article Abhishek Bansal 1 Sanjay Singh 1 M. A. Saleem 2 Sarim Imam 3 Sidhartha institute of Pharmacy, Dehradun. Luqman College of Pharmacy, Gulbarga . Azad Institute of Pharmacy and Research, Lucknow. Microemulsion based emulgel formulations of valdecoxib was developed by using ethyl oleate (EO) as oil, tween-80 in different proportions with propylene glycol (PG) as surfactant/ co-surfactant along with water and incorporated into carbopol 940 as gellant.Microemulsions were characterized for optical birefringence, globule size, polydispersity andconductivity. All microemulsion were stable, transparent, oil in water type and in globulesize range of 12.4-15.3nm. The prepared emulgels were evaluated for pH, drug content,viscosity, in vitro drug release study using dialysis membrane, and skin irritationtest. The pH and drug content of emulgels was in acceptable range of topical application. The viscosity was increased as the proportion of tween-80 and ethyl oleate increased. The in vitro release of valdecoxib was also increased as the proportion of tween-80 increased. Therelease was in the order of 3:1>2:1>1:1 ratios of tween-80 to PG. The release obeys Higuchi’s diffusion equation and follows first order kinetics.All the emulgels were free from skin irritation and were stable at room temperature. From the study it can be concluded that microemulsion based emulgel formulation containing tween-80: PG in the proportion of 3:1 was the best formulation. https://biomedpharmajournal.org/vol1no1/preparation-and-evaluation-of-valdecoxib-emulgel-formulations/ valdecoxib microemulsion  emulgel in vitro release partition determination