Modeling the physiological factors that affect drug delivery from a nipple shield delivery system to breastfeeding infants.

An apparatus was designed to mimic lactation from a human breast. It was used to determine the influence of milk fat content and flow rate, and suction pulse rate of a breastfeeding infant upon the release of a model compound from a nipple shield delivery system (NSDS). The NSDS would be worn by a mother to deliver drugs and nutrients to her infant during breastfeeding. Sulforhodamine B dye (SB) was used as model compound and formulated as a dispersible tablet to be placed within the NSDS. Increasing suction pulse rate from 30 to 120 pulses/min clearly correlated with increased cumulative release of SB for the same volume of milk passed through the NSDS. No distinct correlation was found between flow rates (1, 5, and 8 mL/min) and SB release, possibly because of competing factors controlling release rate at different flow rates. A highly similar SB release rate into two fat content fluids (2.9 and 4.2 wt %) was observed for identical flow conditions. This proof of concept study outlines a novel method to mimic lactation from a breast, and future studies will lead to effective methods to identify key physiological factors that influence drug release from a NSDS.