# First Fluorescence Method for Native Quantification of Pirtobrutinib Used for Treatment of Cancer in its Market Form and Biological Fluids; Application of Greenness

## TL;DR

A new fluorescence method is developed to accurately measure pirtobrutinib, a cancer drug, in biological fluids and its market form.

## Contribution

This is the first fluorescence method for native quantification of pirtobrutinib using a micellar system.

## Key findings

- The method uses SDS to enhance pirtobrutinib's fluorescence for detection.
- The technique is sensitive with a detection limit of 8.66 ng/mL.
- The method was validated and successfully applied to human plasma and drug formulations.

## Abstract

In order to determine the appropriate dosage of pirtobrutinib for treating mantle cell lymphoma that has returned or has not responded to prior treatment, a novel, straightforward, sensitive, and quick first spectrofluorometric approach has been devised. The technique uses 2% w/v sodium dodecyl sulfate (SDS) as an anionic surfactant to micellarly increase the drug’s natural fluorescence. Following excitation at 320 nm, the increased fluorescence intensity of pirtobrutinib was observed at 380 nm. An assay method for determining the researched drug was developed by analyzing the drug’s interaction with SDS and taking advantage of the increased fluorescence intensity. With a detection limit of 8.66 ng mL− 1 and a quantitation limit of 26.23 ng mL− 1, the relative fluorescence intensity-concentration graphs were rectilinear for the 30–1000 ng mL− 1 range. The results of the validation of the proposed analytical method in compliance with ICH standards were judged to be satisfactory. The suggested technique was effectively used for detection in tampered-with human plasma and pharmaceutical formulation. A number of assessment tools have lately been presented, as GAPI and AGREE.