744
Views
12
CrossRef citations to date
0
Altmetric
Gynaecology

A new formulation of levothyroxine engineered to meet new specification standards

&
Pages 147-150 | Received 08 Oct 2018, Accepted 24 Oct 2018, Published online: 26 Nov 2018
 

Abstract

Background: Small variations in the dose of levothyroxine have been associated with marked variations in thyroid function in people with hypothyroidism. Accordingly, regulators have identified levothyroxine as a “narrow therapeutic index” drug subject to more stringent regulations compared with other drugs, in terms of the accuracy and stability of the amount of active drug in each tablet (typically required to be 95–105% of the labelled amount over its full shelf life), and its bioavailability geometric mean ratios (90% confidence intervals between 90–111.1%, including 100%).

Review: This review describes a reformulation of a widely used levothyroxine product (Euthyrox.*). The new tablet fulfils all criteria according to the new specification regulations for dosage accuracy over a shelf life of 3 years in all climate zones, and for bioequivalence compared to the conventional formulation used for many years. In addition, a clinical trial demonstrated equivalent exposure between three different tablet strengths of the new formulation, amounting to the same total dose (dose form proportionality). As a consequence, switching from the conventional to the new formulation can be undertaken on a 1:1 dose-for-dose basis, without re-titration or additional thyroid function testing.

Conclusion: The new formulation, which is more stable, will assist in the accurate dosage and titration of levothyroxine in the management of hypothyroidism.

Acknowledgments

Medical writer Dr Mike Gwilt, GT Communications, provided editorial assistance, funded by Merck KGaA.

Notes

1 * Merck KGaA, Darmstadt, Germany.

2 * Merck KGaA, Darmstadt, Germany.

Log in via your institution

Log in to Taylor & Francis Online

PDF download + Online access

  • 48 hours access to article PDF & online version
  • Article PDF can be downloaded
  • Article PDF can be printed
USD 65.00 Add to cart

Issue Purchase

  • 30 days online access to complete issue
  • Article PDFs can be downloaded
  • Article PDFs can be printed
USD 681.00 Add to cart

* Local tax will be added as applicable

Related Research

People also read lists articles that other readers of this article have read.

Recommended articles lists articles that we recommend and is powered by our AI driven recommendation engine.

Cited by lists all citing articles based on Crossref citations.
Articles with the Crossref icon will open in a new tab.