Design and evaluation of thermoreversible in situ gelling system of forskolin for the treatment of glaucoma.
The contact time of a vehicle on the cornea is of utmost importance for ophthalmic drug delivery. The poor bioavailability and therefore poor therapeutic response exhibited by the conventional ophthalmic solutions due to pre-corneal elimination of a drug may be overcome by the use of the in situ gel forming systems, which upon instillation as drops into the eye, undergo a sol-gel transition in the cul-de-sac. The purpose of this work was to develop an ophthalmic delivery system of the forskolin, based on the concept of temperature activated in situ gelation. Poloxamer 407 (Pluronic F-127) is a block copolymer made of poly (oxy ethylene) and poly (oxy propylene). The sol-gel transition is induced by an increase in temperature; however, it depends on the concentration of the polymer and presence of other additives. The developed formulations were therapeutically efficacious (on albino New Zealand rabbit model); reducing intra ocular pressure (IOP) for 12 hours and showed sol-gel phase transition (gelling) temperature of 22 degrees C and sustained drug release 72% +/- 0.056% in vitro behavior over a period of 4 h.
Gupta
Saurabh
S
Department of Pharmaceutics, J.S.S. College of Pharmacy, Ooty, India. saurabh109@yahoo.com
Samanta
Malay K
MK
D000287:Administration, Topical; D000818:Animals; D001682:Biological Availability; D005576:Colforsin / Q000008:administration & dosage* / Q000493:pharmacokinetics / Q000494:pharmacology; D003315:Cornea / Q000378:metabolism; D003692:Delayed-Action Preparations; D004195:Disease Models, Animal; D004337:Drug Carriers / Q000737:chemistry; D016503:Drug Delivery Systems; D005079:Excipients / Q000737:chemistry; D005782:Gels; D005901:Glaucoma / Q000188:drug therapy*; D007429:Intraocular Pressure / Q000187:drug effects*; D008297:Male; D020442:Poloxamer / Q000737:chemistry; D011817:Rabbits; D013696:Temperature; D013997:Time Factors
D003692:Delayed-Action Preparations; D004337:Drug Carriers; D005079:Excipients; D005782:Gels; D020442:Poloxamer; D005576:Colforsin