Quantification of three second generation atypical antipsychotics Iloperidone (ILO), Blonanserin (BLO) and Asenapine (ASE) have been demonstrated using a newly developed extractive spectrophotometric method. Structural characteristic of selected drugs allows them to form colored complex with acid dyes in presence of specific micro environment. Bromocresol green (BCG) was selected as dye. The colored complex has specific UV absorbance between 400 to 800 nm. Experimental conditions including buffer, pH of solution and solvent for extraction were optimized. Iloperidone and blonanserin were reacted with dye in presence of pH 1.2 hydrochloric acid buffer while asenapine was reacted in presence of pH 4.1 acetate buffer. The colored complex was extracted with chloroform and absorbance was measured that follows beer’s low in range of 10-50 μg/mL for iloperidone (r2 = 0.995) and blonanserin (r2 = 0.998) and 5-30 μg/mL for asenapine (r2 = 0.996). Proposed method was validated in terms of precision, accuracy, limit of detection (LOD), limit of quantitation (LOQ) as per the ICH guidelines. Results for inter-day precision (ILO < 2.20 %, BLO < 2.09 %, ASE < 2.43 %), intra-day precision (ILO < 1.74 %, BLO < 1.74 %, ASE < 1.24 %), % recovery (ILO = 98.05, BLO = 99.61, ASE = 98.60), LOD (ILO = 0.35, BLO = 2.41, ASE = 0.39 μg/mL), LOQ (ILO = 1.07, BLO = 7.31, ASE = 1.19 μg/mL) and stability of the drug-BCG complex (ILO = 120, BLO = 120, ASE = 60 min) were found satisfactory. The proposed analytical method is first, simple, reproducible and cost-effective having industrial application in qualitative and quantitative analysis.
