Polymorphism Of Nateglinide Oriented By Siloxane Self-assembled Monolayers

Effects of Self-assembled Monolayers on adjusting polymorphic crystals of diabetes treatment drug-nateglinide were studied in this thesis. Firstly, according to the structure of nateglinide, three different kinds of siloxane agents including NH2CH2(CH2)2Si(OCH3)3, C6H5NH(CH2)3Si(OCH3)3, and BrCH2(CH2)10Si(OCH3)3, were selected to form SAMs on the surfaces of glass slides and the SAMs were characterized.Effects of supersaturation degree and cooling rate were considered in nateglinide crystallizing experiment, and the crystal forms were analyzed by X-ray diffraction and melting point measure. Major conclusions were obtained as below:1,Siloxane SAMs did affect nateglinide crystallization, pure stable forms B and S were observed to form on SAMs, which couldn't be obtained from liquid at the same condition. And the optimal reaction conditions for the crystal form X2 and S were determined.2,Different kinds of SAMs can cause different effects: S form nateglinide were observed on two alkanes SAMs, SAMs-Si-(CH₂)₃-NH₂ and SAMs-Si-(CH₂)11-Br; while it could not appear on aromatic SAMs-Si-(CH₂)₃-NH-ph in whatever reaction condition. But SAMs-Si-(CH₂)₃-NH-ph could lead H form growing on it.3,The growth of S form nateglinide on long hydrocarbon chain alkanes SAMs-Si-(CH-2)11-Br is more effective than growing on short hydrocarbon chain alkanes SAMs-Si-(CH₂)₃-NH₂, for single S form could be obtained on SAMs-Si-(CH₂)11-Br, while a mixture crystal forms were observed on SAMs-Si-(CH₂)₃-NH₂.