An in vitro human mammary epithelial cell permeability assay to assess drug secretion into breast milk

Tao Zhang; Zachary Applebee; Peng Zou; Zhen Wang; Erika Solano Diaz; Yanyan Li

doi:10.1016/j.ijpx.2022.100122

An in vitro human mammary epithelial cell permeability assay to assess drug secretion into breast milk

Int J Pharm X. 2022 Jun 22:4:100122. doi: 10.1016/j.ijpx.2022.100122. eCollection 2022 Dec.

Authors

Tao Zhang¹, Zachary Applebee¹, Peng Zou², Zhen Wang¹, Erika Solano Diaz³, Yanyan Li⁴

Affiliations

¹ Department of Pharmaceutical Sciences, School of Pharmacy, Husson University, Bangor, ME 04401, United States of America.
² Daiichi Sankyo, Inc., 211 Mount Airy Road, Basking Ridge, NJ 07920, United States of America.
³ Department of Biomedical Engineering, SUNY-Binghamton University, PO Box 6000, Binghamton, NY 13902-6000, United States of America.
⁴ College of Science and Humanities, Husson University, Bangor, ME 04401, USA. Current affiliation: School of Food and Agriculture, College of Natural Sciences, Forestry, and Agriculture, University of Maine, Orono, ME 04469, USA.

Abstract

Determining the amount of a drug transferred into breast milk is critical for benefit-risk analysis of breastfeeding when a lactating mother takes medications. In this study, we developed a human mammary epithelial cell (MEC)-based permeability assay to assess drug permeability across the mammary epithelium. Human MEC cell MCF10F formed tight junctions when cultured on Transwells with culture medium containing insulin, hydrocortisone and epidermal growth factor (EGF). Formation of integral cell barrier and morphology of the cells were confirmed by assessing trans-epithelial electrical resistance (TEER), flux of fluorescent tracers and imaging with transmission electron microscopy (TEM). MCF10F cells showed consistent P-glycoprotein (P-gp) transporter expression when culturing on Transwell inserts versus on petri dish. A few P-gp transporter drug substrates were used to estimate the permeability from this assay. Human plasma and breast milk were used as incubation medium in basolateral and apical chambers respectively to mimic physiological conditions. The predicted milk to plasma (M/P) ratios were reasonably good. The current effort to develop the MEC-based permeability assay to facilitate M/P ratio prediction showed promising results. This assay may have a potential to be developed as a useful in vitro technique for determining the transfer of small-molecule therapeutic drugs into breast milk.

Keywords: Drug transport; ER, extraction ratio; FITC, fluorescein isothiocyanate; GH, growth hormone; IVIVE, in vitro to in vivo extrapolation; M/P ratio; M/P ratio, milk to plasma ratio; MEC, mammary epithelial cell; Mammary epithelial cell; P-gp, p-glycoprotein; Permeability; TEER, trans-epithelial electrical resistance; TEM, transmission electron microscopy; TJ, tight junction.