Tuning the Solution-Mediated Concomitant Phase Transformation Outcome of the Piroxicam Monohydrate by Two Hydroxyl-Containing Additives: Hydroxypropyl Cellulose and H₂O

Abstract

Solution-mediated concomitant phase transformation (SMCPT) of the Piroxicam (PCM) monohydrate was found. The PCM monohydrate could simultaneously transform to block Form I and needle Form II in acetone at 31 °C. However, the Form I and the Form II can be selectively grown in the presence of 0.04 mg/mL HPC and 1% H 2 O, respectively. In addition, the morphology of Form I is changed from block to rod-like or even needle with the increase of the concentration of HPC. Based on these phenomena, the roles of hydroxypropyl cellulose (HPC) and H 2 O in the solution-mediated concomitant phase transformation were studied. The mechanisms of HPC and H 2 O to affect the process of SMCPT of the PCM monohydrate are different. In the presence of 0.04 mg/mL HPC, the interactions between the HPC molecules and the PCM molecules was the main factor that governed the process of SMCPT of the PCM monohydrate. However, in the presence of 1% H 2 O, the driving force of SMCPT played the main role. In our work, the outcome of SMCPT could be tuned directly by additives for the first time, which provides a good guide to obtain the pure polymorph in the SMCPT for pharmaceutical industry.

Manipulation of Morphology, Particle Size of Barium Sulfate and the Interacting Mechanism of Methyl Glycine Diacetic Acid

“…After the dynamics simulation, the energy module was used to calculate the energy of each part. The binding energy can be calculated as the following equation [ 29 , 30 ]: where E bind represents the binding energy between MGDA and the crystal surface, E tot is the energy of the system that docks the additive molecular layer after the molecular dynamics simulation, E surf represents the energy of the crystal surface, and E add is the energy of the additive layer. The calculated binding energy can be used to interpret the interactions between MGDA and crystal faces.…”

“…After the dynamics simulation, the energy module was used to calculate the energy of each part. The binding energy can be calculated as the following equation [29,30]:…”

Recent Advances in Polymorph Discovery Methods of Organic Crystals

“…The intermolecular interactions between the polymer and crystal were responsible for the polymorph discovery. Yao et al reported that the pure form I of piroxicam could selectively crystallize in the presence of hydroxypropyl cellulose (HPC) . They found the hydroxyl groups of the HPC molecules could disturb the recognition of the hydrogen bonds in form II, leaving the form I alone during the concomitant crystallization.…”

“…Yao et al reported that the pure form I of piroxicam could selectively crystallize in the presence of hydroxypropyl cellulose (HPC). 59 They found the hydroxyl groups of the HPC molecules could disturb the recognition of the hydrogen bonds in form II, leaving the form I alone during the concomitant crystallization. This method shows good compatibilities with other polymorph discovery methods, enabling its implementation along with traditional methods for discovering new polymorphs.…”

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

“…Then, the suspension was filtered and the obtained crystals were sent for PXRD to determine the solid form so as to determine the critical water mole fraction (x cw ). The experiments were conducted at different temperatures (10,15,20,25,30,35,40, and 45 °C). Golles 26 once reported the water activity coefficient (γ w ) in the water−methanol system.…”