The MTT assay as tool to evaluate and compare excipient toxicity in vitro on respiratory epithelial cells

Introduction:
This text discusses a study that compares the toxicity of various excipients used in pharmaceutical formulations for the respiratory tract. The study utilizes the Calu-3 cell line, a model for the respiratory epithelium, and three in vitro assays to evaluate the toxicity of the excipients. The aim of the study is to provide a tool for screening the toxicity of new excipients and to compare their toxicity to that of already approved excipients.

Key Points:

* The study used the Calu-3 cell line, a model for the respiratory epithelium, to evaluate the toxicity of various excipients.
* Three in vitro assays were used to evaluate the toxicity of the excipients: the MTT assay, the neutral red assay, and the LDh assay.
* The excipients tested included polysorbate 20 and 80, lactose, povidone 30, glycerol, and propylene glycol.
* The excipients were sorted according to their toxic effect and new excipients not yet used in the respiratory tract were classified in this scheme.
* The MTT assay was found to be the most sensitive assay for evaluating the toxicity of the excipients.
* The LDh assay was not suitable for evaluating the toxicity of the excipients due to interference with the enzyme.
* The study provides a tool for screening the toxicity of new excipients and comparing their toxicity to that of already approved excipients.

Main Message:
The study highlights the importance of evaluating the toxicity of excipients used in pharmaceutical formulations for the respiratory tract. The use of the Calu-3 cell line and in vitro assays provides a tool for screening the toxicity of new excipients and comparing their toxicity to that of already approved excipients. This is crucial in the development of new formulations, especially those containing biomolecules or using new delivery strategies, as the choice of excipients can greatly impact the safety and efficacy of the formulation.

Scherliess, Regina. “The MTT assay as Tool to Evaluate and Compare Excipient Toxicity in Vitro on Respiratory Epithelial Cells.” International Journal of Pharmaceutics 411, no. 1–2 (June 2011): 98–105. https://doi.org/10.1016/j.ijpharm.2011.03.053.