(601s) Development of a Novel Infant Drug Delivery Device for Breastfeeding Infants

Few infant drug delivery methods are tailored for dosing and administering oral medications to breastfeeding infants, especially in resource-limited settings. The infant annual mortality rate exceeds 4.8 million annually, and many leading causes of child mortality are largely preventable with safe and easy to administer medications. Therefore, there is a need for development of novel infant drug delivery and dosing methods. In response to this need, we are developing the nipple shield delivery system (NSDS) and a method of testing the device in vitro. The NSDS, when worn by a mother during breastfeeding, releases medications or nutrients from a tablet it contains, into milk consumed by the infant, simultaneously dosing and delivering the active pharmaceutical ingredients. To test this device in vitro, a breastfeeding simulation apparatus is needed to mimic the process of maternal lactation and infant behaviours during breastfeeding. We have developed a simulation apparatus with functionalities for mimicking lactation flow rates through a physiologically accurate breast mimic and for monitoring and mimicking infant suckling behaviours including sucking rate and imparted pressures. The current aim of our research is to increase the physiological accuracy of the apparatus, by developing a method to also test the potential impact of infant tongue use on the NSDS during breastfeeding.  An infant tongue mimic was constructed based on modifications to a peristaltic pump. A metal plate was attached to mimic an infant upper palate, and a piezoresistive sensor was placed in the system to measure the pressure exerted by the tongue mimic and palate mimic on tablets contained in tubing placed in between. The mimic, through peristaltic motion and by applying a range of pressures potentially imparted by an infant tongue, is then used to test the impact of infant tongue movements on release rates of material which could be contained in an NSDS under flow conditions similar to those during breastfeeding.  The release of the model compound sulphorhodamine b from a potential NSDS tablet formulation was quantified from the tongue mimic system at various tongue mimic speeds and applied pressures. Greater than 76% percent release occurred within 600 seconds, well within the 16.6 minute length of an average breastfeed, for tongue mimic contact rates of 0-240 contacts per minute into water flowing at the average expression rate of 6 mL/min. Preliminary results indicate the tongue mimic system can impart pressures and mimic contact rates in the ranges of those of an infant tongue on potential tablets which are being developed and screened for use in the NSDS. This tongue mimic system will improve the accuracy of our breastfeeding simulation apparatus for further in vitro testing of the NSDS as we continue developing this method for oral delivery of medications to infants.