Investigation of a solution‐mediated phase transformation of pranlukast DMF solvate to hemihydrate

Abstract

Pranlukast is a potent selective cysteniyl leukotriene receptor antagonist to treat bronchial asthma and allergic rhinitis, which exists in several crystal forms. In this work, solution-mediated phase transformation process from Pranlukast DMF solvate to the hemihydrate form was studied by using the focused beam reflectance measurement probe combined with powder X-ray diffraction. The influence factors such as temperature, solvent composition, amount of added solid, and stirring rate were investigated. Results showed that higher temperature, larger mole fraction of water, lower amount of added solid, and faster stirring rate could accelerate the solution-mediated phase transformation process.

Thermodynamic and Kinetic Mechanism of the Phase Transition from Aztreonam Dihydrate to Anhydrates

“…Table shows the phase transition time of form C at different temperatures. With the increase in temperature, the driving force for SMPT becomes larger, so the SMPT process becomes faster …”

“…With the increase in temperature, the driving force for SMPT becomes larger, so the SMPT process becomes faster. 16 To further investigate the kinetics process of SMPT of form C, the suspensions were filtered at different time intervals, and samples were taken for PXRD and concentration analysis. 34 the SMPT process of aztreonam from the dihydrate to the anhydrate is a nucleation-dissolution controlled polymorphic transformation process.…”

“…Yao et al studied the SMPT process of piroxicam with different particle sizes and found that form II would nucleate heterogeneously on the surface of piroxicam monohydrate particles with larger particle sizes, while piroxicam monohydrate particles with smaller particle sizes could not provide a nucleation site for form II, which finally transformed into form I. Process analysis technology can realize in situ monitoring of the SMPT process to avoid errors caused by sampling. − As one of the most commonly used process analysis technologies, in situ Raman spectroscopy can conveniently in situ monitor the phase transition of the solid form in solution. For example, Kim and Ulrich used in situ Raman spectroscopy to accurately detect the phase transition process of amorphous, tetrahydrate, and heptahydrate of disodium guanosine 5′-monophosphate and determined the maximum supersaturated concentration of three forms.…”

A study of the heat-mediated phase transformations of praziquantel hydrates. Evaluation of their impact on the dissolution rate

“…This phenomenon may result in differential physical properties, and even chemical stability [ 2 ], among the solid-state forms as a consequence of differences in their behaviour in a given environment [ 3 ]. Currently, the definition of polymorphism includes pseudopolymorphism and amorphous phases [ 4 , 5 ].…”