Cleaning validation for residual estimation of olmesartan medoxomil on stainless steel surface of pharmaceutical manufacturing equipments using swab sampling and HPLC-DAD method

Prevention of cross contamination with active pharmaceutical ingredient is crucial and requires special attention in pharmaceutical industry. Current method validation describes residual determination of olmesartan medoxomil (OLME) on stainless steel surface using swab sampling with a sensitive HPLC-DAD analysis. The acceptance limit was decided as 2 μg swab pro 100 cm^2. Cotton swabs impregnated with extraction solution were used to determine residual drug content. Recoveries were 95.81%, 93.06%, and 96%. 24% with RSD below 1.5% at three concentration levels. Residual concentration was found to be linear in the range of 0.557–5.62 μg/mL, when estimated using Phenomenex Luna C18 (25 cm x 5 μm x 4.6 mm i.d.) column at 1.0 mL/min flow rate at 258 nm. The mobile phase consisted of a mixture of acetonitrile: methanol: phosphate buffer pH 3.5: tetrahydrofuran (28:13:58:1 v/v/v/v). The LOD and LOQ for OLME were found to be 0.07 and 0.22 μg/mL, respectively. The validated method was found to be simple, selective and sensitive for demonstration of cleaning validation of OLME residues on the stainless steel surface.