IN-VITRO EVALUATION OF PLURONIC F127-BASED CONTROLLED-RELEASE OCULAR DELIVERY SYSTEMS FOR PILOCARPINE

The overall objective of this study was to develop pluronic F127 (PF12 7)-containing formulations of pilocarpine hydrochloride (PHCL) suitabl e for controlled-release ocular delivery of PHCL. Various aqueous form ulations were evaluated containing 1% w/v PHCL and 25% w/v PF127 alone or with one of the following additives present. poly(ethylene glycol) 4600 (PEG), poly(vinylpyrrolidone) 10 000 (PVP), poly(vinyl alcohol) 10 000 (PVA), methylcellulose 15 cP (MC), and hydroxypropyl methylcell ulose 80-120 cP (HPMC). The in vitro dissolution of the PF127 formulat ions and the pilocarpine release profiles from them were obtained simu ltaneously at 34 degrees C and room temperature using a membraneless i n vitro model. It was observed that the PEG-and PVP-containing PF127 f ormulations of PHCL dissolved the quickest and released the drug at a significantly faster rate than the control PF127 formulation, which ha d no additive present. The PF127 formulations of PHCL containing MC or HPMC exhibited the slowest dissolution rates and released the drug th e slowest. The same rank order was observed at each temperature for th e dissolution and PHCL release profiles of each formulation. On the ba sis of the in vitro results, the PF127 formulations of PHCL containing MC or HPMC as an additive showed potential for use as controlled-rele ase ocular delivery systems for PHCL.