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Biomedical subjects

B Schnieders

Publications and source records attributed to B Schnieders.

31 records · Page 2Linked to original sources

[Bioavailability, proof of efficacy and their consequences for drug legislation (author's transl)].

Drugs should be effective for the indicatons stated, they should not involve risks which would not be justified in relation to their benefit and they should be of the necessary quality. It is the objective of drug legislation to warrant these requirements in its area of jurisdiction. It has become a necessity to revise current legislation; it is going to be replaced by a new law. A corresponding bill is being considered by Parliament at present. The present and the future legal situation with regards to proof and safeguarding of the bioavailability of pharmacologically active substances and the necessary prerequisites and rules for the procedure of clinical testing of drugs to prove their efficacy and safety is described.

Animals↗

Characterization of rapidly labelled rat liver ribonucleic acid showing high affinity for columns of methylated albumin on kieselguhr.

Most of the rapidly labelled RNA from rat liver submitted to column chromatography on methylated albumin on kieselguhr remains tightly bound to the column and can only be recovered by elution with m-ammonia. The tightly bound RNA is composed mainly of DNA-like RNA. The binding capacity is dependent not only on base composition but also on molecular size: the heavier RNA molecules show a greater affinity to the column than do the lower-molecular-weight components. Rapidly labelled mouse liver and Saccharomyces cerevisiae RNA show similar behaviour to rat liver RNA on columns of methylated albumin on kieselguhr.

Albumins↗

Tissue distribution and elimination of digoxin and methyldigoxin after single and multiple doses in dogs.

Glycoside concentrations in plasma and various tissues of dogs were determined after a single and repeated intravenous administration of tritium-labeled digoxin and beta-methyldigoxin. Twenty-four hours after single dosing, the highest concentrations were measured in the kidney. This was followed by the heart, adrenal gland, liver, pancreas, lung, spleen, diaphragm, and skeletal muscle. The glycoside concentration in the brain was low after a single administration of dogoxin. A higher concentration was found after a single dose of the more lipophilic methyldigoxin. After repeated daily administration, the glycoside concentration in plasma and tissues increased continuously and, except for the brain, reached a plateau level after 6 to 8 days. The accumulation factor for both digoxin and methyldigoxin was 2.6. During daily administration for 10 days, the glycoside cconcentration in the brain increased continuously. The mean accumulation factor in all brain areas amounted to 12.4 for methyldigoxin. The concentration of digoxin and methyldigoxin in the tissues decreased, with mean half-lives of 33 and 28 hr, respectively. Glycoside elimination from the brain was clearly slower. A mean half-life of 73 hr was measured for digoxin and of 154 hr for methyldigoxin. The elimination of digoxin was largely renal, while that of methyldigoxin was largely fecal.

Animals↗