STABILITY OF AN EXTEMPORANEOUSLY COMPOUNDED LEVOTHYROXINE SODIUM ORALLIQUID

The stability of levothyroxine sodium in oral liquid dosage forms comp ounded from commercially available tablets was studied. Levothyroxine sodium oral liquids (25 mu g/mL) were pre pared from tablets and from powder with and without methylparaben preservative and transferred to amber, high-density polyethylene bottles. Five bottles of each tablet- based formulation were stored at 2-8 degrees C, 23-27 degrees C, and 3 8-42 degrees C, and five bottles of each powder-based formulation were stored at 38-42 degrees C. On days 3, 8, 14, 22, 31, 61, and 90, samp les were taken from each bottle and analyzed for drug concentration by stability-indicating high-performance liquid chromatography. There wa s significant degradation of levothyroxine sodium in all the formulati ons. However, the tablet-based formulation without preservative stored at 4 degrees C retained at least 90% of its initial concentration for eight days after compounding. Degradation occurred faster in the tabl et-based formulation with preservative. None of the formulations retai ned greater than or equal to 90% initial potency by day 14. An extempo raneous oral liquid formulation of levothyroxine sodium 25 mu g/mL. co mpounded from crushed tablets was stable for eight days when stored in amber bottles at 4 degrees C.