Formulation and Evaluation of a Transdermal Patch of Diclofenac Sodium for Sustained Pain Relief

Transdermal delivery represents an attractive alternative to oral drug delivery. So the present research work was aimed to develop matrix type transdermal patches of Diclofenac sodium using polymers HPMC K 15M, ERS 100 and EC and plasticizers DBP & PEG 400 via solvent casting method for low dose (6.25 mg) & high dose (12.5 mg) of drug. This formulation would help to avoid non-compliance of the tablet dosage form. The spectra of drug and physical mixtures of drug-polymers were taken by using FTIR spectrophotometer and confirmed the absence of incompatibility between drug (Diclofenac sodium) and the physical mixture of polymers (HPMC K15M, ERS 100 and EC). Thus, concluded that Diclofenac sodium can be formulated in to a transdermal patch with the above mentioned polymers. Based on in-vitro drug studies, Diclofenac sodium loaded with polymers HPMC K 15M-ERS 100 with DBP as plasticizer was considered as the best formulation, in both high and low doses of drug, (6.25 mg & 12.5 mg) which exhibited the drug release of 3.39 mg/cm2 /12 hrs and 6.08 mg/cm2 /12 hrs respectively. The patches were found to be stable for 2 months with respect to Diclofenac sodium content and there was no significant change in physico- chemical and drug release characteristics of the films. From the present investigation, it may be concluded that such matrix type transdermal patches of Diclofenac sodium may provide sustained transdermal delivery for prolonged periods in the management of migraine, which can be a good way to bypass the extensive hepatic first pass metabolism. The result of the study showed the feasibility of formulating rate-controlled transdermal films of Diclofenac sodium for effective control and prophylaxis of migraine. Further in- vivo investigations are required to correlate in-vitro permeation studies for the development of suitable transdermal system of Diclofenac sodium.