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Acute endophthalmitis was unilaterally induced in 8 rabbits by intravitreal injection of 5 micrograms Escherichia coli endotoxin. A reproducible increase in aqueous humour polymorphonuclear neutrophils and total protein content was observed after 24 h (mean +/- SD: 2400 +/- 274 X 10(6)/l and 3.7 +/- 0.4 g/l, respectively). In the opposite eye only minor changes occurred, making it suitable as a paired control. The intraocular penetration of ceftazidime was then studied in 30 rabbits after i.v. injection of 50 mg/kg body weight. The mean penetration into aqueous humour of the eyes with and without endophthalmitis was 64 and 10%, respectively. In the vitreous body the corresponding penetration was 5 and 1%. The concentration of ceftazidime achieved in the intraocular structures was sufficient to inhibit the growth of pathogens, i.e. Enterobacteriaceae, commonly responsible for intraocular infections.

The elimination kinetics and penetration of ceftazidime into skin blister and lymphatic fluid were studied in nine healthy volunteers following a 1 g iv bolus injection. From the concentration time curve in plasma the following pharmacokinetic parameters (mean +/- S.D.) were calculated: elimination half-life 1.85 +/- 0.33 h; area under the curves 127 +/- 12 mg . h/l; apparent volume of distribution: 21.1 +/- 2.61; total plasma clearance: 133 +/- 13 ml/min and renal clearance: 109 +/- 7 ml/min. Urine recovery after 8 h was 82% of the administered dose. Nearly the same elimination rate constant, half-life and area under the curve were demonstrated for blister fluid and lymph. The penetration of ceftazidime into cerebrospinal fluid (n = 19), aqueous humour (n = 21) and pleural effusions (n = 5) were studied in patients after a 2 g iv bolus injection. In patients with normal meninges (n = 14) the penetration was poor: the concentrations were less than 1 mg/l. In patients with meningitis (n = 5) levels of 18, 17, 16, 1 and 0.8 mg/l were found. Aqueous humour penetration was satisfactory, and a mean concentration of 11 +/- 4 mg/l corresponding to a penetration ratio of 19% was found. The penetration of ceftazidime into large pleural effusions was also good with concentrations from 17 +/- 3 to 28 +/- 2 mg/l, corresponding to a mean penetration ratio of 38%.

High-performance liquid chromatography on a Supelcosil LC-HN2 analytical column in weak anion exchange mode has allowed separation of ascorbic acid, in less than 5 min, from other interfering substances in serum and aqueous humour. UV monitoring at 254 nm enables ascorbic acid to be detected at 20 pmol level. A method for determination of ascorbic acid concentration in serum and aqueous humour is described, and values from 10 cataract patients are reported.