Neonatal neutropenia in low birthweight premature infants.

Neutropenia, as defined by common reference values, occurs often in neonates. Its incidence, causes, and clinical consequences have not been studied extensively in premature neonates. Of 208 consecutive infants with birthweight up to 2000 g, 121 (58%) had neutropenia.

Determination of a potential anxiolytic drug (CGS 20625) in human plasma by high-performance liquid chromatography.

An analytical method employing reversed-phase high-performance liquid chromatography is described for the determination of a potential anxiolytic agent in human plasma. This experimental drug candidate has potent and selective affinity for the central benzodiazepine receptor complex. The compound and internal standard are extracted from buffered plasma (pH 9.

An automated method for the determination of diclofenac sodium in human plasma.

An automated method utilizing laboratory robotics has been developed for quantifying diclofenac sodium concentrations in human plasma. The robotic system aliquots the biological sample, adds the internal standard (CGP 4287), extracts the compounds from the acidified biological matrix (pH less than 2) into an organic phase (hexane-isopropyl alcohol), and concentrates the extracts for reversed-phase, high-performance liquid chromatographic (HPLC) analysis. The laboratory robot is directly interfaced to the HPLC system, and the data are automatically collected and results calculated.

Pharmacokinetic and pharmacodynamic comparison of an osmotic release oral metoprolol tablet and the metoprolol conventional tablet.

Four double-blind, Latin-square studies were conducted to compare the pharmacokinetics and pharmacodynamic bioavailability of metoprolol OROS (oral osmotic) and the conventional tablet (CT) of metoprolol. Metoprolol OROS (7/95 mg or 14/190 mg) was administered once daily in doses equivalent to 100 mg of metoprolol CT given once, twice, thrice, and four times a day. In all four studies, lower peak plasma concentrations and longer times to peak were observed after metoprolol OROS than after metoprolol CT, indicating a controlled-release profile for metoprolol OROS.

Automated sample preparation and chromatographic analysis: determination of CGS 10787B and related compounds.

An automated method is described for analyzing biological samples originating from CGS 10787B drug disposition studies. The method incorporates a laboratory robot to prepare plasma and urine samples and a high performance liquid chromatographic system to simultaneously analyze for CGS 10787B, as well as metabolites and drug-related compounds (CGS 12094, CGS 17000, and CGS 17001). The robot allquots the biological sample, adds an internal standard, and performs all the steps necessary for the liquid-liquid extraction and concentration of the drug and related components, while operating unattended around the clock.

Absorption kinetics and model characteristics of orally administered pirprofen.

Pirprofen kinetics can be described by a linear two-compartment model. Absorption kinetics and model parameters were determined by the incremental method from 48 pirprofen plasma concentration-time profiles obtained after administration of single oral pirprofen doses. Statistical comparison of the results gave information on the influence of formulation, dose, and food on pirprofen absorption.

Effect of pirprofen on protein binding of warfarin and tolbutamide in human plasma.

The extent of warfarin and tolbutamide binding to plasma proteins was determined with and without pirprofen by an ultrafiltration procedure employing 14C-labeled drugs. Results from in vitro studies at 37 degrees showed that the degree of binding amounted to 97.8% for warfarin and 95.

Disposition of pirprofen, a new anti-inflammatory drug.

Plasma and urine concentrations of 2-(3-chloro-4[3-pyrrolinyl]phenyl) propionic acid, pirprofen, a new nonsteroidal anti-inflammatory compound, are described for normal male volunteers receiving one or more doses of the drug. Orally administered pirprofen is rapidly and almost completely absorbed from the gastrointestinal tract, resulting in maximum plasma levels in 1 to 2 hr. Mean peak levels are 23 microng/ml after an oral pirprofen dose of 200 mg; lower doses given proportionally lower levels.

Metabolism of tripelennamine in man.

Four polar metabolites were isolated from the urine of human subjects orally treated with tripelennamine, and their structures elucidated by various chemical and physical methods. One of the metabolites, which is a minor one, was identified as an N-oxide of tripelennamine, and the other three as glucuronide conjugates. One of the conjugates, which is a major metabolite, has been assigned a unique quaternary ammonium N-glucuronide structure, since it gave tripelennamine and D-glucuronic acid on incubation with beta-glucuronidase.