Comparison of Potency Estimates for Glucocorticoids Using Two Thymolytic Assay Procedures

Abstract

A comparison of the thymolytic activity for glucocorticoids using a single injection 48-hour assay and a 5-day multiple injection assay is presented. Regression of steroid thymolytic potencies obtained by the 2 technics indicated that potencies estimated from the 48-hour assay were 0.82 times those from the 5-day assay. The weighted mean slope and standard deviation for the 48-hour assay was -0.401[plus or minus] .002 with an index of precision of 0.239. The minimum standard error of the potency estimates from the 48-hour assay was 17%. Potency estimates from the single injection assay were also compared with those from a multiple injection 48-hour assay. The order of thymolytic activity agreed favorably regardless of the assay employed. Quantitative values, however, did not agree, Nevertheless, quantitative differences observed for relative potencies of steroids from thymolytic assays appear to be far less than those recorded using other parameters of glucocorticoid activity.