Researchers from MIT have developed a new chemical nanoemulsion that can help deliver drugs through the skin. Their work demonstrates that, only by using a handful of FDA-approved materials, they can create nano-sized emulsions which turn to gels when they come in contact with the body. These nano-emulsions may have interesting properties for drug delivery through the skin, or perhaps even the nose.
Emulsions are droplets of one liquid suspended in another liquid, like an oil-and-vinegar salad dressing. Mixing these two liquids in a controlled manner can produce nano-sized droplets, which may have superior uptake properties when put on the skin. Yet, producing emulsions takes a lot of external energy, which makes them expensive to manufacturie. The MIT scientists developed a new chemical formulation that can help reduce the manufacturing cost for nano-emulsions while giving control over some of the material’s properties.
First, drugs and other active ingredients can be loaded into the oil phase of the emulsion. Then, the water phase, along with surfactants to help create the emulsion, are added. The surfactants include polyethylene glycol (PEG), a biocompatible polymer that allows the solution to form very small droplets. With just these few ingredients, the researchers demonstrated they could substantially reduce the energy required to create emulsions.
Nanoemulsions are considered a type of nanomaterial, since they contain nano-sized droplets of drug-loaded oil particles. Nanomedicine research has shown that materials and particles on the nano scale have enhanced cellular uptake properties, through natural cellular mechanisms. In the case of these nano-emulsions, it is hypothesized that the oil nano-droplets would be uptaken like nanoparticles if this material was used as a topical or intranasal spray for drug delivery.
In addition, the team wanted to create emulsions that gelled when they reached body temperature. For this, they utilized heat-sensitive polymers called poloxamers, which are FDA-approved and used in drugs and cosmetics. The poloxamers, under higher temperature, rapidly attach to the droplets and force them to pack together, forming a jelly-like solid.
Exciting developments like these could help advance therapeutic strategies for topical, nasal, and inhalable drugs.
Study in Nature Communications: Thermoresponsive nanoemulsion-based gel synthesized through a low-energy process