Identifying beta-glucans and peptidoglycans in medicinal products

INTRODUCTION. Beta-glucans and peptidoglycans are cell wall components of bacteria and fungi that are potential sources of pyrogenic contamination of parenteral medicines. Such impurities can cause adverse immune reactions. Therefore, recently, certain attention has been paid to identification of beta-glucans and peptidoglycans in medicines. Despite the lack of a harmonised detection method for beta-glucans and/or peptidoglycans, pharmaceutical industry uses several methods for identification and quantitation of these impurities.AIM. This study aimed to assess applicability of the existing detection methods for beta-glucans and / or peptidglycans in the medicinal products.MATERIALS AND METHODS. Applicability of detection was examined for beta-glucans and peptidoglycans using amoebocyte lysate and silkworm larvae plasma as reagents. Beta-glucans were detected in Bupivacaine, the product that was previously found to have random glucan impurities. In the drug tests, three types of amoebocyte lysate reagents of different compositions were used reacting to 1) bacterial endotoxins and beta-glucans (lysate with factors C and G); 2) only bacterial endotoxins (lysate with factor C); 3) only beta-glucans (lysate with factor G). Peptidoglycans in Icodextrin were assessed using a reagent from the silkworm larvae plasma. For qualitative analysis, colour of the test solutions was visually assessed after heating them in a dry-air block heater. Kinetic photocolorimetric method was used for quantitation; the primary data were processed using R software.RESULTS. As a result of two tests with amoebocyte lysate reagents (factors C and G) and (factor C), beta-glucans were detected in Bupivacaine. Chromogenic kinetic method using amoebocyte lysate (factor G) quantified the impurity, which exceeded 2,000 pg/mL. For Icodextrin, peptidoglycan reference content (not more than 200 pg/mL) was not exceeded.CONCLUSIONS. Identification methods for beta-glucans and/or peptidoglycans using amoebocyte lysate and silkworm plasma are applicable for identifying these impurities in the medicinal products. While choosing a study method, product composition and analytical purpose are to be considered.