Ketorolac trometamol topical formulations: release behaviour, physical characterization, skin permeation, efficacy and gastric safety.
OBJECTIVE
The objective of this study was to improve systemic delivery of the highly analgesic ketorolac trometamol (ketorolac tromethamine) via the transdermal route, through cost-effective topical formulations, to avoid most of the problems associated with ketorolac trometamol therapy.


METHODS
In-vitro release behaviour of the drug from different microemulsion and emulgel formulations was evaluated. E2 emulgel (based on isopropyl myristate as penetration enhancer) and E7 emulgel (based on Brij 92 as penetration enhancer) were evaluated for their physical properties, rat skin permeation, in-vivo analgesic effect (hot-plate test and the paw pressure test), acute and chronic anti-inflammatory activity and gastric safety.


RESULTS
Isopropyl myristate and the synergistic effect of the two known penetration enhancers (propylene glycol and Brij 92) significantly modulated drug permeation and may be a promising approach for the transdermal delivery of ketorolac trometamol and other drugs. Selected in-vivo tested formulae (E2 and E7) caused significantly less ulcer score and less gastric erosion compared with oral ketorolac trometamol. E7 showed significantly higher analgesic and anti-inflammatory activity compared with E2 with no significant difference compared with oral ketorolac trometamol.


CONCLUSIONS
The developed ketorolac trometamol E7 emulgel appeared promising for dermal and transdermal delivery of ketorolac trometamol, which would circumvent most of the problems associated with drug therapy.
El-Setouhy
Doaa Ahmed
DA
Department of Pharmaceutics, Faculty of Pharmacy, Cairo University, Cairo, Egypt. doaaahmed@hotmail.com
El-Ashmony
Sahar Mohy Ahmed
SM
D000279:Administration, Cutaneous; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage* / Q000493:pharmacokinetics / Q000633:toxicity; D004195:Disease Models, Animal; D004655:Emulsions; D005079:Excipients / Q000737:chemistry*; D005782:Gels; D007249:Inflammation / Q000188:drug therapy / Q000503:physiopathology; D020911:Ketorolac Tromethamine / Q000008:administration & dosage* / Q000493:pharmacokinetics / Q000633:toxicity; D008297:Male; D009226:Myristates / Q000737:chemistry; D010938:Plant Oils / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D019946:Propylene Glycol / Q000737:chemistry; D051381:Rats; D012869:Skin Absorption; D013276:Stomach Ulcer / Q000139:chemically induced
D000894:Anti-Inflammatory Agents, Non-Steroidal; D004655:Emulsions; D005079:Excipients; D005782:Gels; D009226:Myristates; D010938:Plant Oils; C008205:isopropyl myristate; D011092:Polyethylene Glycols; D020911:Ketorolac Tromethamine; D019946:Propylene Glycol; C033084:polyethylene glycol oleyl ether