Effects of Additives on the Morphology of Thiamine Nitrate: The Great Difference of Two Kinds of Similar Additives

Abstract

The growth of thiamine nitrate, in supersaturated aqueous solutions in the absence and presence of sodium alkyl sulfates CH3(CH2) n SO4Na and sodium alkyl sulfonates CH3(CH2) n SO3Na was studied by a single seed crystal growth experiment. It was surprisingly found that the growth of the a-axis of thiamine nitrate is significantly inhibited by CH3(CH2) n SO4Na, thus reducing the aspect ratio of thiamine nitrate, while the aspect ratio of thiamine nitrate in the presence of CH3(CH2) n SO3Na remains almost constant. Furthermore, the mechanism of additives to modify the crystal morphology is proposed: both additives can inhibit the growth of thiamine nitrate by hindering the solute diffusion. However, their unusual behavior is due to the selective adsorption, which was caused by electrostatic and hydrogen bond interactions between solute and additive molecules. In particular, the anionic groups exposed at the end of the additives demonstrate an interesting case in which a small variation in the charge density and hydrogen bonding ability can lead to a marked difference in modifying the crystal growth behavior. The results obtained from this study should be helpful in the performance evaluation and selection of the morphology modifiers for thiamine nitrate crystals.

Effects of Temperature and Solvent Properties on the Liquid–Solid Phase Equilibrium of γ-Pyrazinamide

“…The α-form (needlelike shape) is also undesirable due to the low flowability property, which does not benefit the blending and tableting processes. However, the γ-form with prismatic-like morphology is popular in the industry due to the rapid mixing and filtering processes. , …”

Experimental and Molecular Simulation Studies of the Attachment Behavior of Photoinitiator XBPO Crystals in Different Solvents

“…In order to obtain the growth faces with morphological importance, the crystal morphology of XBPO in vacuum was predicted by the growth morphology method with the COMPASS force field. , The method is based on the attachment energy (AE) model, which supposes that the growth rate of the crystal face is proportional to its attachment energy. This method has been extensively used in the prediction of the crystal habit. − The above simulations were carried out with the Materials Studio 6.0 software (Accelrys Inc., USA)…”

Solubility Measurement and Thermodynamic Correlation of 4-(Hydroxymethyl) Benzoic Acid in Nine Pure Solvents and Two Binary Solvent Mixtures at (283.15–323.15) K

“…Furthermore, the needle-like crystal shows poor fluidity and it can seriously affect the subsequent blending process and the final tableting process. 6 Therefore, it is meaningful to develop efficient methods to modify the crystal morphology to obtain the desired crystal product, 7 which strongly depends on the supersaturation of a solute in a solution during the nucleation process and the crystal growth process. Therefore, it is necessary to determine the accurate solubility of p-HMBA in different solvents, which is beneficial to design and control the crystallization process of p-HMBA.…”

“…p-HMBA usually presents a needle-like crystal, which affects the dissolution rate in vivo. Furthermore, the needle-like crystal shows poor fluidity and it can seriously affect the subsequent blending process and the final tableting process . Therefore, it is meaningful to develop efficient methods to modify the crystal morphology to obtain the desired crystal product, which strongly depends on the supersaturation of a solute in a solution during the nucleation process and the crystal growth process.…”