Analysis of Co-Crystallization Mechanism of Theophylline and Citric Acid from Raman Investigations in Pseudo Polymorphic Forms Obtained by Different Synthesis Methods.

ABSTRACT: Designing co-crystals can be considered as a commonly used strategy to improve the bioavailability of many low molecular weight drug candidates. The present study has revealed the existence of three pseudo polymorphic forms of theophylline-citric acid (TP-CA) co-crystal obtained via different routes of synthesis. These forms are characterized by different degrees of stability in relation with the strength of intermolecular forces responsible for the co-crystalline cohesion. Combining low- and high-frequency Raman investigations made it possible to identify anhydrous and hydrate forms of theophylline-citric acid co-crystals depending on the preparation method. It was shown that the easiest form to synthesize (form 1'), by milling one hydrate with an anhydrous reactant, is very metastable, a

SUBMITTER: Guinet Y 

PROVIDER: S-EPMC9960353 | biostudies-literature | 2023 Feb

REPOSITORIES: biostudies-literature