Lipid Complex Based Gel of Diclofenac for Effective Management of Pain in Bone Fracture

Diclofenac is a selective COX-2 inhibitor and widely used for management of wide variety pain inclusive of postoperative and post bone fracture pain and inflammation. To overcome the limitation of poor solubility, poor permeation, high dosage frequency and gastric side effects its topical dosage forms with better permeation were developed and evaluated. Therefore, the topical polymeric diclofenac gel of its lipid complex was prepared and evaluated for drug content, ex vivo permeation study, in vivo analgesic and in vivo anti-inflammatory activity. The polymeric lipid based gel showed translucent, colorless and clear physical properties with pH 6.24 and viscosity 12.2 cps (before application) and 18.92 cps (after application). The prepared polymeric lipid based diclofenac gel showed high drug content (97.25 +/- 1.39%). Diclofenac gel (plain; F1) showed only 48.24 +/- 2.17% drug release while the gel prepared from the lipid complexes (F2) showed 79.90 +/- 2.49% drug release at the end of 12 h in ex vivo permeation study across the rat abdominal skin. The lipid complex based gel (F2) showed greater analgesia (62.5 %) as compared to that of Standard/ plain gel Fl (57.5 %) in the fractured tibia- induced pain model in rats. In anti-inflammatory activity also, it was evident that lipid complex based gel (F2) showed 81.02 +/- 1.29 as compared to that of Fl which showed 68.05 +/- 2.48% inhibition of carrageenan induced rat paw edema at the end of 24 h. It can be concluded that the polymeric topical gel prepared from the lipid complex of diclofenac may play a vital role in improving the drug flux across the skin and hence can act as the promising topical dosage form for relieving the pain and inflammation post bone fractures in orthopedics.