Endocrine Abstracts

Personalized medicine is a crucial part of modern medicine. As a result, other therapeutic options apart from levothyroxine are considered when treating hypothyroidism. Desiccated thyroid pharmaceuticals, that in addition to thyroxine (T4), contain triiodothyronine (T3), are one of them. ETA recognized the rapid use of desiccated thyroid pharmaceuticals and described specific guidelines for its utilization. The biggest problem of their use is unresolved issues of content that differ between manufacturers, but also between individual series of the same manufacturer Nevertheless, an increasing number of patients are resorting to desiccated thyroid powder in the last two decades. Very few studies that focus on the quantification of T3 and T4 content in desiccated thyroid powder have been done so far. For therapy monitoring and stability studies of described pharmaceuticals, new methods of quantification are necessary. Correspondingly, our goal was to develop a specific, fast, and accurate method for the quantification of T3 and T4 in a desiccated thyroid powder that is applicable in most laboratories. The RP-High-Performance Liquid Chromatography with UV-Vis detection and LC/MS/MS methods were applied for the quantification of T3 and T4 in Pronase® hydrolysates of desiccated thyroid samples. Their analytical yields in samples were high, T4: 98.74% and T3:99.72%obtained by HPLC; T4:99.50 % and T3: 100% by LC/MS/MS. High concordance was shown in analytical yields for T3 and T4 obtained by the methods used. Although LC/MS/MS is a more sensitive method, the fully validated RP-HPLC has been confirmed as a suitable method for the quantitative analysis of total T3/T4 content. The developed method had been improved regarding sample pretreatment by using a commercially available mixture of proteolytic enzymes Pronase® in incubation buffer Tris(hydroxymethyl) -aminomethane and 2-mercapto-1-methylimidazole) which showed high utilization. In conclusion, the methodology used for the pre-analytical processing of thyroid powder and validated HPLC UV-Vis method shows potential for the analytical analysis of thyroxine and triiodothyronine in commercially available thyroid preparations and monitoring the stability of such preparations.