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1 Prednisolone binding in human serum and to recrystallized human serum albumin was measured by continuous ultrafiltration. 2 At serum concentrations of prednisolone up to 0.6 micron, 95.0% was bound but at higher concentrations the binding became non‐linear falling to 80.5% at 1.8 microns. At even higher concentrations binding in serum became linear again and paralleled the binding to albumin which was linear throughout the entire range of prednisolone concentrations. 3 A binding model was proposed which included a saturable component attributable to binding to transcortin and a non‐saturable binding to albumin. 4 Computer simulations using the experimentally determined binding parameters of the model indicated that binding in serum was critically dependent on transcortin concentration and almost independent of albumin concentration.

1 Gentamicin alone (dose 1 mg/kg) or in combination with frusemide (dose 0.25 mg/kg) or piretanide (dose 0.1 mg/kg) was administered intravenously to six healthy male volunteers. 2 Blood samples were collected at various times for 24 h and urine for up to 48 h. 3 Both diuretics increased the renal clearance of gentamicin during the period of the diuresis, without influencing either the glomerular filtration rate or the distribution of the antibiotic. 4 The results are discussed in relation to gentamicin-induced nephrotoxicity.

1 The concentration of oxytetracycline in plasma was studied by microbiological assay after oral administration of five different preparations of the antibiotic. None of these preparations had been studied previously. 2 There was a statistically significant correlation between the time required for 50% dissolution at pH 2 and biological availability, as assessed by the peak plasma level or the area under the plasma concentration‐time curve. 3 The mean bioavailability of oxytetracycline was greatest with preparations of the hydrochloride, and with film‐coated tablets of the dihydrate. In contrast, sugar‐ coated tablets of oxytetracycline dihydrate were associated with poorer dissolution characteristics and reduced biological availability.