No abstract

BMS-753493 is a folate-targeted candidate being developed for the treatment of cancer. As part of preformulation efforts, our aim was twofold - to understand the major degradation pathways and, study its kinetics of degradation to aid drug product development. Given the complexity of degradation, BMS-748285, the epothilone moiety of BMS-753493 was used as model compound to evaluate the major degradation pathway viz; macrolactone versus aziridine ring hydrolysis. Hydrolysis of BMS-753493 was studied in the pH range of 1.5-9.4 in 0.05 M buffers at 0.5 ionic strength and 5-40°C. Three major pathways were identified; carbonate ester hydrolysis and hydrolysis of aziridine and macrolactone rings resulting in addition products with identical masses (m/z = 794) in the pH range of 5-7.5. Similarly, two addition products, D1 and D2 (m/z = 555) were also formed on hydrolysis of BMS-748285 under neutral pH conditions. The reaction products from BMS-748285 were isolated and characterized using LC-MS and LC-SPE-NMR (1-D ¹H and 2-D HMBC, heteronuclear single quantum coherence) analyses. LC-NMR analysis indicated an intact aziridine ring and opened macrolactone ring, resulting in D1 and D2, an isomeric hydroxy acid pair resulting from an alkyl oxygen cleavage. By analogy to BMS-748285, BMS-753493 was also postulated to undergo alkyl cleavage of the macrolactone, forming two epimeric hydroxy acids under neutral pH. The pH-stability data were also consistent with these findings. Additionally, the degradation kinetics for BMS-753493, indicated a U-shaped pH-stability profile with maximum stability at pH 7. Based on the stability and solubility considerations, the pH range of 6-7 was optimal for an injectible drug product development.

We describe the synthesis, chromatographic purification, and isolation of the epothiloneÀfolic acid conjugate BMS-753493, an investigational new drug candidate for the treatment of cancer. The main challenges for process development were the instability of BMS-753493 in aqueous solution, the design and optimization of the preparative chromatography, and the removal of phosphate salts and water from the purified material. The operating conditions of the batch chromatographic purification were optimized using a column adsorption model. The free-salt active pharmaceutical ingredient was isolated via the precipitation of its zwitterion following a careful determination of the isolation parameters that controlled thermal and pH-related decomposition. This process enabled the manufacturing of several batches (10À30 g) of cGMP quality BMS-753493.

Abstract. The reactions of aliphatic and aromatic amines with reducing sugars are important in both drug stability and synthesis. The formation of glycosylamines in solution, the first step in the Maillard reaction, does not typically cause browning but results in decreased potency and is hence significant from the aspect of drug instability. The purpose of this research was to present (1) unreported ionic equilibria of model reactant (kynurenine), (2) the analytical methods used to characterize and measure reaction products, (3) the kinetic scheme used to measure reaction rates and (4) relevant properties of various reducing sugars that impact the reaction rate in solution. The methods used to identify the reversible formation of two products from the reaction of kynurenine and monosaccharides included LC mass spectrometry, UV spectroscopy, and 1-D and 2-D 1 H-1 H COSY NMR spectroscopy. Kinetics was studied using a stability-indicating HPLC method. The results indicated the formation of α and β glycosylamines by a pseudo first-order reversible reaction scheme in the pH range of 1-6. The forward reaction was a function of initial glucose concentration but not the reverse reaction. It was concluded that the reaction kinetics and equilibrium concentrations of the glycosylamines were pH-dependent and also a function of the acyclic content of the reacting glucose isomer.