[The effect of propyl gallate on the activity of various antifungal drugs against filamentous fungi in vitro].

OBJECTIVE: The influence of an antioxidant, propyl gallate (PG), on the activity of amphotericin B (AMB), terbinafine (TBF), butenafine (BTF) and ketoconazole (KCZ) against ocular pathogenic filamentous fungi in vitro was investigated to determine whether PG could increase the antifungal activity. METHODS: Susceptibility tests were performed against 6 isolates of ocular pathogenic filamentous fungi (Fusarium solanae, Fusarium moniliforme, Fusarium poae, Fusarium oxysporum, Aspergillus fumigatus and Aspergillus flavus) and 2 quality control strains (Candida krusei ATCC 6258 and Cadida parapsilosis ATCC 22019) by the NCCLS M38-P broth microdilution method (MIC). PG was added to the incubation media at a final concentration of 400 microg/ml. Antifungal agents were serially two-fold diluted and final dilutions were made in 1640 and PG-1640 culture media to a concentration ranging from 0.0313 to 16 microg/ml for AMB, TBF, BTF and KCZ. One hundred microl of the corresponding diluted inoculum suspension was added to each well of the microdilution tray. The MIC end-point of AMB was determined as 100% growth reduction and the MIC end-point of TBF, BTF, KCZ and PG was determined as 75% growth reduction as compared with the turbidity produced by the control well. RESULTS: At a concentration of 400 microg/ml, PG did not show any antifungal activity under these experimental conditions. The combination of PG (400 microg/ml) with amphotericin B revealed a remarkably increased activity against all of the isolates of ocular pathogenic filamentous fungi and quality control strains. In the combination of PG with terbinafine, a remarkably increased activity was observed against Fusarium solanae, Fusarium poae, Fusarium oxysporum, Aspergillus fumigatu and Aspergillus flavus. The combination of PG with butenafine had remarkably synergistic effect against Fusarium solanae, but did not synergistic or even showed antagonistic effect for other isolates. The combination of PG with ketaconazole was synergistic against Fusarium solanae, but was antagonistic against all other isolates. CONCLUSIONS: Combination of PG and amphotericin has remarkably synergistic effect against all tested ocular pathogenic filamentous fungi isolates. Combination of PG and terbinafine has remarkably synergistic effect against some isolates. The PG-amphotericin combination and the PG-terbinafine combination may have a role in future studies of antifungal eye drops.

[Ocular pharmacokinetics of 0.5% pilocarpine with sodium hyaluronate in rabbits].

OBJECTIVE: To compare the pharmacokinetics of 0.5% pilocarpine containing sodium hyaluronate with 1% generic pilocarpine solution. METHODS: One hundred albino rabbits were divided into 20 groups, each consisting of 5 animals. Ten groups received 0.5% pilocarpine containing sodium hyaluronate and 10 groups received 1% generic pilocarpine solution as control. The aqueous humor was withdrawn at 5, 10, 20, 30, 40, 60, 90, 120, 150, and 180 min after instillation. The drug was extracted from aqueous humor with dichloromethane and was detected by reversed phase high performance liquid chromatography (HPLC). RESULTS: The average recovery rate of pilocarpine from aqueous humor was 98.2%. The minimum detectable concentration was 0.025 micro g/ml. The peak concentration and half-life of pilocarpine in aqueous humor were 4.46 micro g/ml at 10 min and 31.83 min, respectively, in the experimental group. Whereas, the peak concentration and half-life of pilocarpine in aqueous humor were 2.25 micro g/ml at 20 min and 22.98 min, respectively, in the control group. The peak concentration of pilocarpine in aqueous humor in the experimental group was 1.98 (P < 0.05) times higher than the control group. The area under curve of the drug concentration-time (AUC(0 - 180)) in the experimental group was 1.75 times higher than the control group. CONCLUSION: Pilocarpine (0.5%) containing sodium hyaluronate significantly increased the peak concentration of pilocarpine, shortened the time of reaching peak concentration and prolonged the half-life in aqueous humor. These results indicate that 0.5% pilocarpine with sodium hyaluronate significantly increases ocular bioavailability of pilocarpine.