[Antibiotic ophthalmic solutions evaluated by pharmacokinetic parameters of maximum concentration in the aqueous].

PURPOSE: In order to determine whether the one-component method for calculating drug concentration in the aqueous(AQCmax) is useful for selecting an appropriate ophthalmic solution, 6 general purpose antimicrobial ophthalmic solutions already on the market were investigated. METHODS: The drugs examined were levofloxacin (LVFX), chloramphenicol(CP), erythromycin lactobionate(EM), micronomicin sulfate(MCR), cefmenoxime hydrochloride(CMX) and disodium sufobenzyl penicillin(SBPC). Fifty microliters of each solutions was instilled into the cul-de-sac of New Zealand White rabbit eyes 3 times at 15-minute intervals. The drug concentrations in(the anterior sac aqueous,: this is wrong) the aqueous humor 10, 30, 60, 120 and 240 minutes after the final instillation were examined by high performance liquid chromatography(HPLC) and/or bioassay. The AQCmax was calculated using the one-compartment method. RESULTS: The calculated AQCmax was 2.5 micrograms/ml (HPLC method) and 2.28 micrograms/ml (Bioassay Method) for LVFX, 2.17 micrograms/ml for CP, and 0.45 microgram/ml for EM. The AQCmax for CMX, MCR and SBPC could not be calculated by the one-compartment method. CONCLUSION: The AQCmax of LVFX was higher than that of the 2 other general purpose antimicrobial ophthalmic solutions. The AQCmax of these drugs might be a useful parameter for selecting an appropriate ophthalmic solution for the treatment of infected eyes.

[Penetration of antibiotics into second degree burned skin in rabbits].

This study was designed to determine the concentration of antibiotics administered systemically in second degree burned skin in rabbits. I: Penetration of Sulfobenzyl-penicillin (SBPC) into Deep Dermal Burn (DDB). The concentration of SBPC was determined in the skin and serum of four groups. One group acted as control and the other three had DDB. The rabbits in each were administered 100 mg/kg of SBPC by 2 hour drip infusion. In burn groups SBPC was given on the 1st, 4th and 7th post burn day, respectively. In the control group, peak concentration in the serum and skin was obtained at the end of the drip administration decreasing quickly thereafter. In every burn group, SBPC was detected in the skin and peak concentration was obtained at the end of the drip administration. After drip infusion, the SBPC level in the skin remained longer in the burn groups than in the control group. In the first day burn group, SBPC could not be detected until 1 hour after the initiation of the drip, while in the other two burn groups, SBPC could be detected a little at 30 minutes. The SBPC skin to serum ratio at the end of the drip administration in each burn group was half the value of that in the control group. II: Penetration of Cefpiramide (CPM) into Superficial Dermal Burn (SDB). The concentration of CPM was determined in the skin and serum of five groups. One group acted as control and the other four had SDB. The rabbits in each group were administered 20 mg/kg of CPM intravenously by bolus injection. In burn groups CPM was given at 8, 16, 24 and 48 hours, respectively, after burn inducement. As in the control group, CPM was detected in the SDB at every stage after burn inducement. However, CPM remained in the burned skin longer than in the non-burned skin. In the 16-hour-after-burn-group the CPM level reached its peak at 30 minutes after injection, while in the other three burn groups, the maximum level was achieved at 15 minutes. The CPM concentration in the skin of each burn group was the same or higher than that of the control group. III: Antibiotics systemically administered were determined in second degree burned skin. However, the degree of penetration was different according to the degree of burn.(ABSTRACT TRUNCATED AT 400 WORDS)

Effect of ursodeoxycholate on the biliary excretion of cefotiam and sulbenicillin in patients with percutaneous transhepatic biliary drainage.

The effects of ursodeoxycholate administration on the biliary excretion of the antibiotics cefotiam and sulbenicillin were studied in five patients with stable hepatic function receiving percutaneous transhepatic biliary drainage for obstructive jaundice. Cefotiam (I g) and sulbenicillin (2 g) were administered intravenously before and after ursodeoxycholate administration, and the maximum concentrations of the antibiotics in the bile and total amounts excreted in the bile during the 4 h after administration were determined. After ursodeoxycholate administration, both the maximum concentration of cefotiam in the bile and the amount excreted increased significantly. Ursodeoxycholate also increased the peak concentration and total excretion of sulbenicillin. For both cefotiam and sulbenicillin, the amount of antibiotic excreted in the bile during the 4 h after administration showed a significant correlation with the amount of bile acids excreted in the bile. This strongly suggests a common mechanism for the biliary excretion of these antibiotics and bile acids. Ursodeoxycholate administration is a benign way to increase both the concentration and the total amount of antibiotic excreted in the bile. Therefore, it may be useful in the treatment of serious biliary tract infections, especially in patients receiving biliary drainage.

Comparison between sulbenicillin and piperacillin levels in serum and in bronchial secretions--a pharmacokinetic study.

In order to assess pharmacokinetic differences between sulbenicillin (S) and piperacillin (P), two penicillin derivatives, 24 in-patients, 12 males and 12 females mean age 59.4 years, suffering from recurrent bronchial infections were enrolled. Patients were randomly allocated to S (12 patients) and to P (12 patients) and were given 2 g i.m. every 12 h of the awarded antibiotic, for a 7-day period. At the first and 7th day blood samples (0.25, 0.5, 1, 2, 4, 6, 8 and 12 h after dosing) as well as sputum samples (1, 2, 4, 8, 12 h after dosing) and urine samples (3, 6, 9 and 12 h after dosing) were collected, and the levels of S or P were determined by bacillus subtilis test. The pharmacokinetic analysis was performed by a standard program. On day 1 and 7 the mean peak serum concentration occurred at the first hour for S (39.9 +/- 5.2; 40.9 +/- 5.1 mcg/ml, respectively) and for P (32.2 +/- 5.4; 33.1 +/- 5.4 mcg/ml, respectively). Serum AUC0-12 and AUC0-00 (mg/l.h) levels of S were significantly higher (p less than 0.01 or less) than those of P on day 1 and 7. Similarly MRT (8 h) and Cmax (mg/l) where higher but only on day 7. Sputum AUC0-12 (mg/l.h) level of S was significantly higher (p less than 0.05) than that of P on day 1 and 7. In conclusion serum and sputum S appear to have a different pharmacokinetic profile in respect to P. However, when compared to the AUC, both drugs reach antibacterial levels.