AN IMPROVED PROCESS FOR THE PREPARATION OF LEVOTHYROXINE SODIUM WITH REDUCED LEVELS OF IMPURITIES

摘要

The invention relates to an improved process for the preparation of Levothyroxine sodium with reduced levels of impurities. The invention also provides Levothyroxine sodium pentahydrate free from 3,5-Diiodothyronine or d-enantiomer of thyroxine. The invention also provides Levothyroxine sodium pentahydrate having liothyronine below 0.5% wt / wt.