Simulated digestion: Nanomaterial made from lipids and silicon dioxide improves absorption of pharmaceuticals

Apr 27, 2012

(Phys.org) -- Some medicines have to be taken either before, after, or during a meal because food ingredients can affect its absorption or bioavailability. Australian researchers have now encapsulated drugs in a matrix of silicon dioxide and lipids to simulate the administration of pharmaceuticals with food. As the researchers report in the journal Angewandte Chemie, drug absorption is increased through control of the enzymatic digestion of the lipid droplets.

For example, the body only absorbs fat-soluble vitamins A and D in the presence of some fat. Also, the bioavailability of many poorly water-soluble drugs increases when they are taken with high-fat meals. There are many techniques for the lipid-based delivery of pharmaceuticals, including emulsions, micelles and “packaging” in liposomes. These methods prevent the active ingredients from precipitating out and improve transportation to the absorption sites in the gastrointestinal tract. However, in order for the to become active in the body, it must be released from its shell. The enzymatic decomposition of the lipid coating plays an important role in this process, but it has proven to be difficult to control. In addition, it is difficult to calculate the extent to which such lipid “packaging” really increases the bioavailability of a drug.

Clive Prestidge and a team at the University of South Australia and Monash University have now developed a controllable packaging type. Their material consists of a nanostructured network of nanoparticles that contains nanoscopic containing the drug. This system is produced by generating a fine emulsion of the drug-containing oil droplets in an aqueous phase. The silicon dioxide particles collect around the droplets at the phase boundary. Spray-drying results in solid microparticles of entrapped lipid droplets.

The team has demonstrated that the lipid in these microparticles is enzymatically digested much more rapidly than pure lipid drops. This is because the nanostructured silicon dioxide network holds the enzymes close to their substrate. The size of the silicon dioxide particles used and the porosity of the resulting determine how fast the enzymatic decomposition of the lipids occurs.

Animal trials with Celecoxib, a drug used to treat arthritis, showed a higher drug content in plasma when the pharmaceutical was orally administered in this new form rather than in its pure state or as drug-containing lipid drops. In contrast to Celecoxib-containing lipid drops, the release rate did not vary from batch to batch or after a longer storage period.

The new nanomaterial imitates the food effect in a predictable fashion and allows for better control of drug release, it could minimise the food effect on drug absorption and enhance more predictable therapeutic responses.

Explore further: Recycling industrial waste water: Scientists discover a new method of producing hydrogen

More information: Clive A. Prestidge, Hybrid Nanomaterials that Mimic the Food Effect: Controlling Enzymatic Digestion for Enhanced Oral Drug Absorption, Angewandte Chemie International Edition, dx.doi.org/10.1002/anie.201200409

add to favorites email to friend print save as pdf

Related Stories

Study brings secrets of brain cell communication closer

Oct 05, 2011

(Medical Xpress) -- Researchers at The University of Queensland's Queensland Brain Institute (QBI) have taken a significant step towards unravelling the mechanism by which communication between brain cells occurs.

COPI complex is a regulator of lipid homeostasis

Nov 25, 2008

Magazine articles describing ways to burn fat, lose weight, etc. are omnipresent in Western culture, but science's understanding of the way fat is stored in the cells of the human body is rather slimmer.

Nanoparticles create biocompatible capsules

Mar 06, 2006

An innovative strategy of mixing lipids and nanoparticles to produce new drug and agricultural materials and delivery vehicles has been developed by researchers at the University of Illinois at Urbana-Champaign.

New route to map brain fat

May 04, 2011

Mapping the fat distribution of the healthy human brain is a key step in understanding neurological diseases, in general, and the neurodegeneration that accompanies Alzheimer's disease in particular. Antonio Veloso and colleagues, ...

Recommended for you

A greener source of polyester—cork trees

Apr 16, 2014

On the scale of earth-friendly materials, you'd be hard pressed to find two that are farther apart than polyester (not at all) and cork (very). In an unexpected twist, however, scientists are figuring out ...

A beautiful, peculiar molecule

Apr 16, 2014

"Carbon is peculiar," said Nobel laureate Sir Harold Kroto. "More peculiar than you think." He was speaking to a standing-room-only audience that filled the Raytheon Amphitheater on Monday afternoon for the ...

Metals go from strength to strength

Apr 15, 2014

To the human hand, metal feels hard, but at the nanoscale it is surprisingly malleable. Push a lump of metal with brute force through a right-angle mould or die, and while it might look much the same to the ...

User comments : 0

More news stories

Leeches help save woman's ear after pit bull mauling

(HealthDay)—A pit bull attack in July 2013 left a 19-year-old woman with her left ear ripped from her head, leaving an open wound. After preserving the ear, the surgical team started with a reconnection ...

Venture investments jump to $9.5B in 1Q

Funding for U.S. startup companies soared 57 percent in the first quarter to a level not seen since 2001, as venture capitalists piled more money into an increasing number of deals, according to a report due out Friday.