Aigul Ye. Malmakova
A.B. Bekturov Institute of Chemical Sciences, Kazakhstan
Title: IR and NMR studies of drugs complexation with β-Cyclodextrin
Biography
Biography: Aigul Ye. Malmakova
Abstract
β-cyclodextrin (β-CD) is widely used to increase stability and solubility of drugs in water, to increase the bioavailability of drugs, etc., to reduce the side effects of Dimedrol, Clophelin and Tolperisone. Their β-CD inclusion complexes were obtained with dissolving of drug (as hydrochloride and/or base) and β-CD via slow addition of drug solution to the β-CD solution. The formation of inclusion complexes were affirming by IR and NMR spectroscopy. Using the example of a comparative analysis of IR spectra (Сlophelin-base or Dimedrol-base, β-CD and its complexes, Fig. 1 and Fig. 2), it was shown that resulting crystalline product was a physical mixture of Сlophelin-base and β-CD (Fig. 1). While the spectrum of complex of Dimedrol-base+β-CD was characterized by absence of absorption bands observed in drug spectrum at 746.8; 700.8 and 2770-3030 cm-1, related to aromatics. This suggests the formation of inclusion complex by the “occurrence” of both phenyls of Dimedrol into the β-CD cavity, i.e. “guest”-“host”=1:2. Evidence of inclusion of Dimedrol-base molecule into the β-CD internal cavity by the 1Ð NMR spectroscopy was a change in the chemical shifts of the protons H-3 (-0.18), H-5 (0.09) and H-6 (0.18), directed into the internal cavity β-CD molecules and exposed to the incorporated molecule. On the other hand, the descreening of H-9 (-0.22) and C-7 (-1.17), C-9 (-0.24) and C-10 (-0.54) and the screening of both Cq (1.41) Dimedrol's phenyl fragments showed that both phenyl were incorporated into an internal cavity of two β-CD.