Investigations on the Polymorphism and Pseudopolymorphism of the Glucocorticoid Triamcinolone:  New Findings for a Well-Known Drug

Abstract

The glucocorticoid triamcinolone was investigated for polymorphism. If crystalline suspensions of the commercial available drug (form A) are stirred in different solvents, a new and hitherto unknown modification (form B) is always obtained. However, in water, a third form is isolated, which is a monohydrate (form C). Form B represents the thermodynamically most stable solvent-free modification at room temperature, whereas the commercially available form A is metastable. The stable form B crystallizes in the chiral, non-centrosymmetric monoclinic space group P2 1 with two crystallographically independent molecules in the asymmetric unit. In the crystal structure, the molecules are connected by O-H‚‚‚O hydrogen bonding into a three-dimensional network. Dehydration of the modification C by thermogravimetry leads to its transformation into the metastable form A. The differential scanning calorimetry (DSC) thermograms of forms B and C exhibit three endothermic events, while form A shows two endothermic events. The last endothermic signal is assigned to the melting of the compounds. The X-ray powder diffraction investigations of the residues formed in these thermal events indicate the formation of at least one additional solvent-free modification.

[Cu(X-salicylato)2(N,N-diethylnicotinamide)2(H2O)2] complexes: conformational polymorphism and its consequence in supramolecular hydrogen-bonding networks formation

“…The development of novel polymorphs of potential and existing drugs has for some time been a method for modifying and improving their physical properties [5]. The control of the process of nucleation and/or crystal growth at the beginning of crystallization from solvents is potential way for modifications of novel polymorphs across a range of industries involving dye [6], food stuff [7], drugs [8], and explosives [9]. The control of morphology and polymorphism is essential to achieve optimized molecular configurations and physical properties and to understand the structure-property relationships and design of new materials [10].…”

Structural, Thermodynamic, and Kinetic Aspectsof the Trimorphism of Hydrocortisone

“…In view of the importance of polymorphism we have started systematic investigations on the polymorphism of glucocorticoids 6–8. In recent investigations our interests focus on hydrocortisone (Scheme ), which is one of the most effective antiphlogistic and immune‐suppressive drugs and exhibits extremely high anti‐inflammatory properties.…”

Application of hydroxyapatite nanoparticles in development of an enhanced formulation for delivering sustained release of triamcinolone acetonide

“…DSC analysis of TR shows endothermic peaks in the 242-280°C range, which is characteristic of polymorph A and B. 35,36 The glass transition temperature (T g ) of PLGA in situ forming gels, including TR (15%) and GL (3%), was 49.8°C. This is also evidence for the transition of TR from a crystalline to an amorphous form in the presence of GL, and the existence of elastic properties in the PLGA membrane.…”