Niosomes as transdermal drug delivery system for celecoxib: in vitro and in vivo studies

Nonionic surfactant vesicles containing celecoxib (CXB) as an anti-inflammatory drug were prepared using, Span 60 or Span 40 and cholesterol in the ratios of 1:0, 1:1 and 1:2. Prepared vesicles were characterized for encapsulation efficiency, particle size and drug release. The drug encapsulation efficiencies varied from 60.55 to 80.35 %. The vesicle size ranged from 170 to 235 nm. The high encapsulation was achieved by the ratio 1:1 of span 60:cholesterol and this formula showed significant in vitro release of the drug (80 %) as compared to other forms (P < 0.05). Among niosomal gels investigated, poloxamer 407 niosomal gel showed significant drug release (72 % after 12 h) over the other forms (P < 0.05). The results also showed that the release of CXB from the niosomes and niosomal gels obeyed the Higuchi's diffusion model. The anti-inflammatory activity of the drug from different niosomal gel formulations was also studied using Carrageenan-induced rat paw edema method. The results showed that there is significant anti-inflammatory activity (75.45 %) of the poloxamer niosomal gel on rat paw edema (P < 0.05).