THE EFFECT OF PILOCARPINE ON OCULAR LEVOBUNOLOL ABSORPTION FROM OPHTHALMIC SOLUTIONS

Studies in vitro and in vivo were conducted to investigate the effect of pilocarpine on ocular absorption of levobunolol when both drugs wer e formulated in one solution dosage. The ocular absorption of levobuno lol is pH-dependent. Due to the large buffering capacity of pilocarpin e at PH 5.5, the ocular absorption of levobunolol from pilocarpine-con taining solutions was reduced by approximately four-fold as compared t o a non-pilocarpine-containing formulation at pH 7.2. The ocular absor ption of levobunolol in the presence of pilocarpine at acidic pH was e nhanced by the use of sulfosuccinates, specifically Schercopol CMS.