Transdermal Delivery of Ketorolac

A reservoir type transdermal patch for delivery of ketorolac, a potent analgesic agent was studied. The low permeability of skin is the rate-limiting step for delivery of most of the drugs. Studies were carried out to investigate the effect of permeation enhancers on the in vitro permeation of ketorolac across rat skin. The reservoir type transdermal patch was fabricated and the core was filled with gel system of a non ionic polymer HPMC (hydroxypropyl methyl cellulose) formulated in PBS (phosphate buffer saline) solution of pH of 5.4 along with isopropyl alcohol at 25% w/w concentration. Various permeation enhancers' viz. dimethyl sulphoxide, d-limonene, eucalyptus oil and transcutol (diethylene glycol monoethyl ether) were incorporated into the gel system. Permeation enhancement of ketorolac with different enhancers followed the order eucalyptus oil> transcutol> DMSO> d-limonene. Cyclic terpene containing eucalyptus oil was found to be the most promising chemical permeation enhancer for transdermal delivery of ketorolac. The increase in concentration of eucalyptus oil further enhanced drug permeation with maximum flux being achieved at 10% w/w of 66.38 microg/cm(2)/h. Further enhancement of permeation rate of ketorolac across skin was attained by application of abrading gel containing crushed apricot seed onto the skin. There was 5.16 times enhancement and flux of 93.10 microg/cm(2)/h was attained. A reservoir type transdermal patch for delivery of ketorolac thus appears to be feasible of delivering ketorolac across skin.