Methodology for preclinical assay of pseudoallergy of injectable drugs (Ⅱ)—— rat model for assay of cutaneous pseudoallergy induced by injections

Abstract

To develop animal models and methodologies for assay of pseudoallergy induced by injectable drugs. Rats cutaneous anaphylactoid reaction model was developed by intravenous injection of 0. 6% Evans blue(EB) followed by intracutaneous injection of test substance solutions 50 microL. Diameters of subcutaneous blue spots and EB exudation were assayed. Rat anaphylactoid reaction was characterized as vascular hyperpermeability which was measured by diameters of blue spots inside the skin and the EB exudation of the blue spots. Compound 48/80 caused severe bluing and EB exudation in the skin by inducing obvious vascular hyperpermeability which indicated that it can induce rat skin pseudoallergy. Normal saline or 5% glucose injection showed no obvious reactions. The rat pseudoallergy model was validated by intracutaneous injections of western drug injections and Chinese medicine. Rats could be developed into skin pseudoallergy model for preclinical safety evaluation of injectable drugs. The pseudoallergy reaction in this model is of high clinic consistency, sensitivity, reproducibility, and maneuverability. The model is suitable for the evaluation for pseudoallergy induced by injectable products prepared from Chinese materia medica This model can also be used for safety assay and quality control in manufacturing process, spot checking of marketed products, screening of allergen as well as studying of pseudoallergy mechanism.