IMMUNOGEN DESIGN, ANTISERUM CHARACTERIZATION, AND VALIDATION STRATEGYFOR A SPECIFIC RIA OF TRIAMCINOLONE ACETONIDE

The validation of a specific radioimmunoassay (RIA) for the determinat ion of triamcinolone acetonide (TAA) using a polyclonal antibody is de scribed, The direct and sensitive assay used only 0.2 mL of sample, Li nearity was demonstrated from 0.025-3.20 ng/mL, with a day-to-day RSD of less than 14% and accuracy of less than 5.8 % bias for quality cont rol samples, The percent cross-reactivity of structurally related phar maceutical compounds and endogenous steroids was less than 0.001 %, In addition, three structural analogs of TAA were tested for cross-react ivity, The cross-reactivity of two of the compounds was less than 0.10 %. The cross-reactivity of the third was less than 10%. The RIA for T AA has been utilized for the analysis of samples from both clinical an d preclinical pharmacokinetic studies, The method is specific, simple, and relatively low-cost, The importance of antisera specificity in me thod validation is illustrated in this report when analysis of biologi cal samples in various matrices/species is needed to support clinical trials for drug development of TAA, We describe the immunogen design, antiserum characterization, and validation strategies used to verify t he performance of the RIA.