Severe non-specific adsorption of verapamil, nifedipine, prazosin and nadolol was observed during ultrafiltration of the drug solutions through the Centriflo CF 50A, YMT, YMB and Visking membranes. ...The results question the adequacy of the ultrafiltration procedure for the protein binding assay of the tested drugs.
It was shown in experiments with collimators that the changes with time in the shape of histograms constructed from the measurements of the alpha-activity of 239Pu microsamples depend on the ...direction of the flow alpha-particles. If the flow of alpha-particles was directed to the Polar Star, the dependence of the probability of the realization of histograms of similar shape on time disappeared. The measurements of alpha-particle flows directed to the East and West revealed a high probability of the repeated realization of histograms of similar shape in 1436 min, i.e., in a sederal day. A comparison of "west" and "east" histograms showed a high probability of the realization of similar "west" histograms 718 min (half a sideral day) later than "east" histograms. The results suggest that the shape of histograms depends on the pattern of the starry sky and the space-time inhomogeneity corresponding to this pattern.
High performance liquid chromatography has acquired great importance recently for an analysis of the drugs in biological fluids of the body. Phase inversion sorbents are particularly widely used ...today. However, the use of ion-exchange sorbents is fairly promising for an analysis of the drugs capable of ionizing in an aqueous solution. The authors illustrate the use of the latter ones for determination in the blood, urine and saliva of man of a number of the cardiologic drugs (etmozine, nonachlazine, verapamil, prazosin, propranolol, nadolol). Ion-exchange sorbents make it possible to attain better results than inverse phase ones, since they retain the drugs selectively and do not retain the endogenous substances of lipid nature. As regards verapamil, prazosin and propranolol, the unchanged drug and polar metabolites could be determined jointly, with such a determination being not feasible with the use of phase inversion sorbents. Separation of the diastereoisomers of nadolol was achieved in the blood and urine of patients who received the drug.
