Development and validation of a sensitive and specific radioimmunoassay for the determination of cicaprost in biological samples.

Cicaprost is a potent, chemically and metabolically stable PGI2-mimetic. Pharmacodynamic effects were observed after oral administration of approximately 10 micrograms in man when plasma levels were in the low pg-range. The present report describes the development of a selective antiserum and a tracer with high specific activity and their use for the RIA determination of Cicaprost in biological samples.

Pharmacokinetics and pharmacodynamics of cicaprost in healthy volunteers after oral administration of 5 to 20 micrograms.

In a Phase I study, the tolerability, pharmacodynamics and pharmacokinetics of cicaprost have been investigated in 6 male volunteers given 5, 10, 15 and 20 micrograms as tablets of the beta-cyclodextrin clathrate. Individual inhibition of platelet aggregation and changes in facial colour (measured by chromametry) were dose-dependent and reached a maximum 30 to 60 min post-dose. The maximum inhibition of platelet aggregation was about 40%.

Development, validation and practical use of a sensitive and specific radioimmunoassay for the determination of iloprost.

Iloprost is a potent, clinically effective PGI2-mimetic. Therapeutic plasma levels are in the low pg-range and currently analyses of biological samples are performed by GC/MS after antiserum-column extraction. Although this method exhibits high sensitivity and specificity it permits only limited numbers of samples to be analyzed owing to time-consuming work-up.

Development and application of a radioimmunoassay of the new progestagen gestodene.

A radioimmunoassay for the determination of gestodene (17-ethinyl-13-ethyl-17 beta-hydroxy-4,15-gonadien-3-one) in human plasma is described with regard to procedure, specificity, accuracy and reproducibility. Antiserum was raised against gestodene-3-O-(carboxymethyl)oxime-BSA in rabbits and [9,11-3H]-gestodene tracer was used with a specific radioactivity of 2.16 TBq/mmol.

Radioimmunological determination of levonorgestrel and ethinylestradiol.

A sensitive and specific radioimmunoassay for ethinylestradiol (EE2) and levonorgestrel (LN) has been developed. Antisera were raised in rabbits after injection of EE2-6-carboxymethyloxime-aminocaproic acid and LN-3-carboxy-methyloxime linked to bovine serum albumin. The sensitivity of immunoassay was 15 pg/ml for EE2 and 10 pg/ml for LN.