Quantification of an Anti-Rheumatic Agent: Upadacitinib in Biological Fluid (Plasma) By LC- MS/MS

Aim: Upadacitinib is a Janus kinase/signal transducers and activators of transcription (JAKs) of cytoplasmic tyrosine kinase that has been proven to be effective in treating inflammatory conditions and various immunological diseases/disorders, including rheumatoid arthritis. Tofacitinib and ruxolitinib, which are members of this drug's first generation, did not affect JAK1/JAK3 or JAK1/JAK2 receptors specifically due to a lack of subtype selectivity. As far as we are aware, there is currently no method for the accurate quantification of the anti-rheumatic drug upadacitinib in biological fluid.
Material and Materials: To detect upadacitinib in biological fluid, an unique and reliable LC-MS/MS technique must be developed. Using a symmetric C18 column (150 x 4.6 mm, 3.5 m) and isocratic elution with acetonitrile: water (50:50) as the mobile phase, we created a unique bioanalytical approach here. Formic acid was used to bring the mobile phase's pH down to 4.0, and the flow rate was 1 ml/min. The retention time of the medication was discovered to be 3.12 min, and the total run time was set to 7 min.
Results: With a correlation coefficient (r2) of 0.999, the upadacitinib linearity curve was established at concentrations ranging from 12.5 ng/ml to 100 ng/ml. The theoretical plates, resolution, and tailing factor are system suitability parameters found to be within the acceptable criteria. The recovery studies indicated that the developed method can extract the acceptable % amount of drug 100.3%. The matrix effect study indicates there is no effect of matrix on recovery, the result shown as 104.20% and also other validation parameters like precision, LOD, LOQ are within the acceptable criteria.
Conclusion: The created techniques enable a precise, delicate, and consistent analytical process for the estimation of Upadacitinib in
biological matrix. The stability studies indicate the drug is stable in different accelerated stability study conditions the results are within limits.