Structural polymorphism and solubility of medicinal drugs (Using Perindopril as an Example)

The correlation between the structural polymorphism of perindopril salt C₁₉H₃₂N₂O₅ · C₄H₁₁N and its bioavailability has been investigated. During the crystallization of perindopril salt from an organic solvent, a low-symmetry perindopril polymorph is formed when the most polar solvent is used. It is shown that the dissolution rate in water, which is a measure of the bioavailability of any pharmaceutical product, is higher for the perindopril salt grown from the least polar solvent and that the structure has a monoclinic symmetry.     

Overlap parameters of configurations and wave functions

A generalization of the method of parametric configuration investigation to the case where the parity selection rule is violated is proposed. The parameters of configuration overlap are given, the transition from nonorthogonal to orthogonal parameters is investigated, and the possibility of obtaining sufficiently accurate wave functions on the basis of these parameters is shown.Translated from Izvestiya Vysshik Uchebnykh Zavedenii, Fizika, No. 5, pp. 108–112, May, 1991.     

Study of fast charged particles with a Cerenkov detector on the KOSMOS-900 orbiter

Experimental data, for the period from April 30, 1977 to October 10, 1979, on the spatial distribution of secondary electrons with energy greater than 15 MeV and protons with energy greater than 400 MeV at an altitude of 500 km as well as data on the fluxes of relativistic electrons with energy exceeding 15 MeV, arising in the decay phase of magnetic storms and trapped in the outer radiation belt, are presented. The results of measurements of solar cosmic rays (SCR) in the vent on November 22, 1977 are discussed.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 69–74, October, 1987.     

Inverse Problem of the Theory of Reflection for Three-Layer Structures

Journal of Experimental and Theoretical Physics - We propose an original approach to analyzing the exact solution of the direct problem in the theory of reflection that allows an algorithm for...