A green bioanalytical spectrofluorimetric approach for estimation of Avapritinib anti-tumor drug; application to quality control and clinical studies.

Aims: Gastrointestinal stromal tumors (GISTs) account for about 80% of the mesenchymal tumors of the GI tract. About 5000-6000 patients are diagnosed in the United States (US) alone, and up to 14.5 cases per million discovered in Europe annually. Avapritinib (AVP) is a potent selective targeted medication that has been recently approved, by the US Food and Drug Administration, in 2020 for treatment of GISTs. AVP is currently considered the first-line treatment for mutant GIST, which is resistant to other medications. This in turn stimulates the need for fast, green, and efficient methods for routine AVP estimation in quality control and clinical studies.

Materials and methods: The proposed approach designs a spectrofluorimetric tool to estimate AVP in different matrices, based on a nucleophilic substitution reaction. A highly fluorescent product was measured at 535 nm following excitation at 470 nm. The research procedure was bioanalytically validated within AVP range between 80 and 900 ng mL^-1, where the limit of quantitation (LOQ) was 15.78 ng mL^-1.

Conclusion: The developed approach was successfully applied to investigate AVP in content uniformity testing of tablet dosage forms, and biological plasma in AVP pharmacokinetic study. The proposed approach could be recommended for AVP therapeutic drug monitoring.