Human milk harnessed to administer medicine to infants

Researchers from the Monash Milk Team have demonstrated the power of human milk as a highly effective vehicle for administering certain medicines to infants, as published in the European Journal of Pharmaceutics and Biopharmaceutics.

The Monash Milk Team are trailblazers in understanding how milk and milk-like systems can be harnessed to enhance oral drug delivery. In this preclinical study, they found the amount absorbed of a medicine called clofazimine (its ‘oral bioavailability’) increased by more than 2.5-fold when administered with human milk. Similarly, the oral bioavailability of clofazimine was significantly higher when administered in both human and bovine milk using a neonatal piglet model, suggesting comparable enhancement in oral bioavailability could be achieved with human or bovine milk.

Clofazimine has previously been used in the treatment of leprosy and is currently used to treat tuberculosis. In this study, the researchers were testing how they could enhance the absorption of clofazimine among infants with the parasitic disease known as cryptosporidiosis, which is responsible for significant diarrhoeal morbidity and mortality in young children in low- and middle-income countries.

While clofazimine has in recent years been used as a treatment option in these settings, its effectiveness is limited by its inability to dissolve in our gastrointestinal contents. Human milk solves this problem by providing a favourable environment for the clofazimine to dissolve into, without needing other potentially toxic components to be included with the drug.

“Poorly soluble medicines such as clofazimine do not dissolve well in the stomach after administration, and therefore developing age-appropriate formulations which are both safe and effective is challenging,” said PhD candidate Ellie Ponsonby-Thomas, lead author on the study.

“We know from previous studies that formulations aimed at infants involving milk-based vehicles can help medicines dissolve in the stomach, so we were excited to see this also applies to the administration of clofazimine.”

Co-author Professor Ben Boyd, Head of the Monash Milk Team, said the findings further validate the enormous potential of milk-based vehicles to improve the oral bioavailability of medicines such as clofazimine, particularly among vulnerable infants where treatment options are limited.

“Through our research over the years, we’ve consistently been able to demonstrate the way in which certain medicines are able to ‘piggyback’ with the milk, which our body treats like food and digests,” Boyd said. “Through this process, the milk and drug are absorbed, thereby enhancing the effectiveness of the drug.

“In particular, we’ve been interested in how the delivery, absorption and overall therapeutic efficacy of poorly soluble medicines, such as clofazimine and some antimalarial medicines, can be enhanced in low- and middle-income settings where conventional forms of medicines are not suitable or available for infants.”

Although the positive effects of milk on the performance of certain medicines are clear, using it to enhance medicines is limited by several challenges in developing countries. This includes the need to refrigerate the milk prior to consumption and the variations in the quality of milk.

“Naturally derived milk presents many hurdles in developing countries, which means that its implementation as an FDA-approved ingredient in medicines is difficult,” Boyd said.

“Therefore, finding a way to develop milk-based vehicles as low-cost, infant-friendly formulations, which are highly regulated in a food context, could provide alternative solutions for treating prevalent diseases in low-and middle-income countries.”

Image credit: iStock.com/Natalya Trofimchuk