Vladimir P. Torchilin - Nanopreparations for delivery of undeliverable drugs
Poorly soluble drugs have serious problems with their delivery and dosage forms. Formulation strategies using nanocarrier systems, such as polymeric micelles, can solve the problem. Micelles from PEG-diacyllipids, such as PEG-PE, are of particular interest. Alternatively, the layer-by-layer (LbL) technology (coating nanoparticles with oppositely charged polyelectrolytes) can be applied to prepare stable nanocolloids of poorly soluble drugs. In some cases, the use of nanopreparations is the only way to meet medical needs. Thus, for the blood pool CT imaging, one has to prepare long-circulating contrast-loaded nanoparticles. In other cases, poor stability of potential drugs creates a problem, such as with siRNA, and the use of nanocarriers may provide a solution. Polymeric micelles containing a hydrophobic derivative of siRNA can serve as an example. We will discuss the preparation, properties, and anti-cancer activity of drug-loaded PEG-PE micelles and LBL nanoparticles and other “nanoapproaches” for making deliverable dosage forms of “undeliverable” substances.