Green Analytical Chemistry Compliant UV-Visible Spectrophotometry Estimations for Sunitinib Malate

Sunitinib malate (SNM), a vital antineoplastic drug, needed a greener and more rapid spectrophotometric method for its pharmaceutical quantification. This study involves developing and validating two effective and environmentally friendly ultra-violet-visible (UV-Vis) spectrophotometric methods for measuring SNM in bulk form and capsule formulations produced in-house. These methods were developed using the zero-order UV-Vis spectrophotometry (method I) and area under the curve (UV-Vis–AUC) (method II) approaches. The method sensitivities and selectivity were optimized using ethanol as a green solvent, which was not found to be reported before for estimation of SNM. Both devised methods underwent validation to ensure precision, accuracy, and sensitivity to comply with the International Council for Harmonization Q2 R1 guideline. SNM was formulated as in-house capsules using microcrystalline cellulose. The validated methods were used to estimate SNM as a bulk assay from in-house capsules. The results demonstrated excellent Beer–Lambert linearity within 3–18 μg/mL with acceptable accuracy and adequate precision. The limit of detection (LOD) (method I: 0.43 μg; method II: 0.15 μg) and limit of quantification (LOQ) (method I: 1.32 μg; method II: 0.45 μg) values confirmed the method's sensitivity. Additionally, the method exhibited exceptional specificity and was free from interferences from used excipients. This newly developed UV-spectrophotometric method complies with principles for green analytical chemistry as assessed with the Analytical Greenness Assessment (AGREE) tool and was found to be rapid, simple, cost-effective, and reliable for the routine analysis of SNM to assist with its pharmaceutical research in the future.