An ultra high-performance liquid chromatographic method was developed to study the cinitapride metabolism. Metabolites were generated from the incubation of cinitapride with human liver microsomes. Cinitapride and its metabolites were separated by reversed-phase mode using a formate aqueous solution (pH 6.5) and acetonitrile as the components of the mobile phase. Chromatographic conditions, including the establishment of an elution gradient, were optimized for obtaining the maximum number of resolved components in the minimum analysis time. Experimental design and multicriteria decision-making strategies were utilized to facilitate the optimization of chromatographic conditions. Figures of merit were evaluated with cinitapride standards and incubated samples. Limits of detection are about 0.03 μmol/L, and repeatabilities are better than 0.06% for retention times and better than 3.5% for concentrations. The method was applied to characterize the in vitro cinitapride metabolism with human liver microsomes.

An ultra-high performance liquid chromatographic method has been utilized to obtain metabolic profiles of cinitapride with liver microsomes of humans and various mammal species such as rats, mice, mini pigs, dogs, and monkeys. Metabolites have been generated by incubation of cinitapride in the presence of microsomes using nicotinamide adenine dinucleotide phosphate as a cofactor. Incubation times from 15 to 60 min have been assayed. Cinitapride and its metabolites have been separated by reversed-phase C(18) mode using ammonium formate aqueous solution (pH 6.5) and acetonitrile as the components of the mobile phase. Concentrations of metabolites in the incubated samples have resulted in an excellent source of multivariate data to be used to extract metabolic information. Statistic parameters and principal component analysis have been used to compare the in vitro metabolism of humans with the other species.