The design of novel validated methodologies targeting many goals such as simplicity, greenness, analytical efficiency and sustainability, has gained great concern in quality control units. In this sense, fast, white and sustainable analytical procedures were optimized and validated for estimation of Allopurinol (ALP) with either Benzbromarone (BZB) or Thioctic acid (TIO) in their fixed dose combinations. In procedure I, capillary zone electrophoresis (CZE) was performed using fused silica capillary (50 cm, 50 μm id), a background electrolyte solution of 50 mM borate buffer (pH 8.5) with 17 s injection time and 30 kV voltage. The diode array detector was operated at 210 nm for the three drugs. Separation occurred in 4 min with migration times 2.9, 3.3 and 3.6 min for ALP, BZB and TIO respectively. Linearity range was 10–200 μg/mL for the three drugs. Additionally, simple spectrophotometric methods were designed for simultaneous estimation of the two binary mixtures. Method I was direct absorbance measurement for determination of ALP and TIO simultaneously at 250 and 330 nm respectively. Similarly, direct Amax measurement at 356 nm was implemented for estimation of BZB in mixture with ALP. Methods II and III were based on the ratio difference and ratio spectra derivative measurements for the quantitation of ALP using BZB as divisor. The developed methods were validated conforming to the ICH guidelines and assessed for greenness and sustainability using AGREE model and the hexagon tool. On studying the whiteness features, the suggested methods were compared with 7 reported methods using the recently introduced RGB12 model.