Phase Transitions of Ipidacrine Hydrochloride Polymorphs and Hydrates

CNS Drug Reviews, Vol. 4, No. 3, Fall 1998

Ipidacrine (NIK-247, 9-amino-2,3,5,6,7,8-hexahydro-1H-cyclopenta[b]quinoline monohydrochloride monohydrate) is a novel substance synthesized by the National Research Center for Biologically Active Compounds in the Russian Federation. Ipidacrine was earlier referred to by the chemical name amiridine (7). This compound contains the structure of 4-aminopyridine and is structurally very similar to ...

Solid State Crystallinity, Amorphous State, and Its Implications in the Pharmaceutical Process

Many drugs exist in crystalline solid form due to reasons of stability and ease of handling during the various stages of drug development. Crystalline solids can exist in the form of polymorphs, solvates or hydrates. Phase transitions such as polymorph inter-conversion, formation of hydrates, desolvation of solvates, and conversion of the crystalline to amorphous form may occur during various p...

Multi-Component-Multiphase Flash Calculations for Systems Containing Gas Hydrates by Direct Minimization of Gibbs Free Energy

The Michelsen stability and multiphase flash calculation by direct minimization of Gibbs free energy of the system at constant temperature and pressure, was used for systems containing gas hydrates. The solid hydrate phase was treated as a solid solution. The fugacities of all components of the hydrate phase were calculated as a function of compositions by the rearranged model of van der Wa...

Detection of Phase Transitions in the Studies of Active Substanes and Solid Dosage Forms

Polymorphism is the ability of a compound in the solid state to exist in different crystalline forms. Molecules, having the same chemical composition, exhibit different spatial arrangements and/or exist in different configurations and conformations [1]. In pseudopolymorphs (solvates) molecules of solvents are incorporated into the crystal lattice. Contrary to the crystalline forms of polymorphs...

Comparison of the Performance of Different Thermodynamic Models for Liquid Phase in Predicting the Phase Behavior of Hydrogen Hydrates with THF