ABSTRACT
Recently, the U.S. Food and Drug Administration (FDA) approved the first oral antiviral drug to treat mild to moderate cases of coronavirus disease. The combination of nirmatrelvir with an already used protease inhibitor class drug, ritonavir, has led to Paxlovid®. Several studies considered drug repositioning as the first trial for new drugs. The precise identification and quantification of polymorphs in raw materials and finished products are important to researchers involved in pharmaceutical development and quality control processes. In this work, we study the solid-state behavior of the antiretroviral drugs ritonavir and lopinavir in raw materials and in milled compositions. The results indicate that mixtures of ritonavir Forms I and II are found in different batches of raw materials from the same manufacturer; besides three equal crystalline samples, an amorphous batch was found in lopinavir. Furthermore, the milling process of the already amorphous lopinavir seems to facilitate the amorphization of ritonavir as well as the production of some unexpected crystalline forms of ritonavir. A phase transition of ritonavir Form I to Form II is only observed when co-milling with amorphous lopinavir. These findings reveal significant variations in phase purity of raw materials that affect the processing and solid-state properties, representing risks for the product quality.
Subject(s)
Coronavirus Infections , Ritonavir , Humans , Lopinavir/chemistry , Antiviral Agents , Coronavirus Infections/drug therapy , Drug CombinationsABSTRACT
The crystal structure of baricitinib has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional techniques. Baricitinib crystallizes in space group I2/a (#15) with a = 11.81128(11), b = 7.06724(6), c = 42.5293(3) Å, β = 91.9280(4)°, V = 3548.05(5) Å3, and Z = 8. The crystal structure is characterized by hydrogen-bonded double layers parallel to the ab-planes. The dimers form a graph set R2,2(8). The sulfone ends of the molecules reside in the interlayer regions. The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™ (PDF®).