New York, Nov 12 (IANS): A milk powder containing anti-retroviral drugs, which are not very soluble in water, can help better treat and prevent HIV infection in babies, research shows.

The team found a new method of altering a protein in cow's milk to bind with an anti-retroviral drug.

Most anti-retroviral drugs are not tolerated by very young children.

One of the most commonly prescribed anti-retroviral drugs for treating and preventing HIV infection, Ritonavir, has undesirable side effects and oral-delivery problems.

"Its physico-chemical properties challenge its administration to infants," said Federico Harte, associate professor of Food Science at Pennsylvania State University in the US.

To solve that problem, Harte looked to a group of proteins in cow's milk called caseins.

The caseins in mammals' milk are natural delivery systems for amino acids and calcium from mother to young and, Harte reasoned, might deliver Ritonavir molecules as well.

Subjecting milk to ultra-high pressure homogenisation enhances the binding properties of the caseins, the findings showed.

"As a result of this enhanced binding of molecules, we believe a milk powder containing Ritonavir can be used as baby formula, providing a transport system for a drug that is not very soluble in water," Harte added.

"Right now we are running tests and we are in the final stages of an experiment in which we gave three different formulations to piglets," Harte concluded.

The study was published online in the Journal of Pharmaceutical Research.