Para-Aminosalicylic Acid (PAS) in Chronic Pulmonary Tuberculosis

Crystal Engineering of Multicomponent Crystal Forms of p-Aminosalicylic Acid with Pyridine Based Coformers

“…4-Aminosalicylic acid or p -aminosalicylic acid (PAS) is a potential antibiotic used in the second line treatment of multidrug-resistant tuberculosis (MDR-TB). − PAS has also been effective toward ulcerative colitis , and Crohn’s disease . Recent studies have shown a significant interest in engineering new multicomponent solids based on PAS (cocrystals and salts) − by adopting a supramolecular synthon approach involving the well-known acid···pyridine synthon. − Earlier work by our group as well as others have reported 19 solid forms of PAS with various pyridine based compounds which include 10 cocrystals, two cocrystal hydrates, two salt cocrystal hydrates, and five salts. − It is apparent from these studies that two types of interactions occur between the acid group of PAS and the pyridine ring of the coformer: a single O–H···N hydrogen bond with the carboxylic group and pyridine ring lying in different planes and a two-point recognition involving O–H···N and C–H···O with the carboxylic and pyridine groups lying in one plane.…”