Multicomponent System of NPS-1034, an Orally Administered Lung Cancer Drug Candidate, with Sulfonic Acids and Solid State Characterization

NPS-1034 is a drug candidate targeted for the regulation of c-MET/AXL receptor tyrosin kinase activity. NPS-1034 was developed to improve efficacy and reduce toxicity by targeting c-MET/AXL related signaling pathways. However, NPS-1034 is practically insoluble in almost all organic solvents as well as aqueous media (pH 1, 4.5, and 7.5). We attempted to improve the physicochemical properties of NPS-1034 by forming multicomponent systems with a wide variety of sulfonic acids including methanesulfonic acid, 1,2-ethanedisulfonic acid, p -toluenesulfonic acid, and camphorsulfonic acid. Solid state characterization of NPS-1034 salts and amorphous with sulfonic acids was conducted, and the crystal structures of four salts and NPS-1034 were compared and investigated. Sulfonic acid salts of NPS-1034 decreased the melting point of NPS-1034 as much as −155.43 °C. Solubilities of NPS-1034 and salts of NPS-1034 were measured to develop lipid-based formulation for the GLP toxicity study. Solvents studied include oleic acid, poly(ethylene glycol) 400, and ethanol. Solubility of amorphous of NPS-1034 with camphorsulfonic acid showed a significant increase in all three solvents. This work will give some insight into how various types of sulfonic acids interact with pharmaceutically important compounds containing the pyrrolepyridine moiety.