STABILITY AND IN VITRO DISSOLUTION BEHAVIOR OF 3´-AZIDO-5´OOXALATOILTIMIDINIC ACID (AZT-Ac) POLYMORPHS

Congreso; 2° Reunion Internac. Cs. Farm.; 2012

Pharmaceutical polymorphism may have great consequences in the life of an active pharmaceutical ingredient (API), affecting important physicochemical and biopharmaceutical properties such as the stability, dissolution (DR) and absorption rates. These differences are usually more evident when amorphous and crystalline phases of an API are compared, because amorphous solids are far from the equilibrium, showing higher solubility and DR than their crystalline counterparts, and being more unstable with high tendencies to devitrify. In this work, we evaluate the solid-state stability and intrinsic dissolution behavior of two solid-state forms of AZT-Ac, a zidovudine (AZT) derivative which shows comparable antiviral activity and less cytotoxicity than AZT. AZT-Ac-1 is a crystalline form and AZT-Ac tbw is an amorphous phase obtained by lyophillisation from t-butanol-water.