Reduction in Intraocular Pressure by the Instillation of Eye Drops Containing Disulfiram Included with 2-Hydroxypropyl-.BETA.-cyclodextrin in Rabbit

Abstract

We have studied the effect of disulfiram (DSF) solution containing 2-hydroxypropyl-beta-cyclodextrin and hydroxypropylmethylcellulose (DSF eye drops) on intraocular pressure (IOP) in experimentally induced ocular hypertension in rabbits. In both in vitro and in vivo transcorneal penetration experiments using rabbit corneas, only diethyldithiocarbamate (DDC) was detected in the aqueous humor, while DSF was not detected. The amount of DDC penetration for 0.25% DSF eye drops was about 4-fold that for 0.1% DSF eye drops in in vivo transcorneal penetration experiments. The elevation in IOP was induced by the rapid infusion of 5% glucose solution (15 ml/kg of body weight) through the marginal ear vein, and IOP was measured with an electronic tonometer. The induced elevation in IOP was reduced by the instillation of 0.1-0.5% DSF eye drops, and the IOP-reducing effect increased with the increase in DSF concentration in the drops. Nitric oxide (NO) levels increased in the aqueous humor following the infusion of the 5% glucose solution, and this increase was also suppressed by the instillation of DSF eye drops. In conclusion, the present study demonstrates that the instillation of DSF eye drops has an IOP-reducing effect in rabbits with experimentally induced ocular hypertension, probably caused by the suppression of NO production.