Nanotechnology in Drug Development and Life Cycle Management

Abstract

Nanotechnology deals with the design, production, characterization and application of sub-micron-sized particles. The popularity and effectiveness of small-sized particles can be extended to broad areas in pharmaceutical, medical, chemical and engineering applications mainly due to their unique properties. The recognition for nanotechnology is well expressed by a great funding of US$1.28 billion to the US National Nanotechnology Initiative (NNI) for the fiscal year 2007. Also, it is estimated that the drug market for nanotechnology could be worth as much as US$200 billion by 2015 (Breen, 2006). Examples of nanoparticulate drug carriers are liposomes, microemulsions, nanosuspensions and nanoparticles (Mumper, Cui & Oyewumi, 2003). These systems can be formulated into a variety of dosage forms including parenteral, tablets, hard gelatin capsules, soft gelatin capsules and oral liquid dosage forms. In many studies, nanoparticulate carriers have been demonstrated as effective delivery systems for a wide range of small molecular drugs as well as macromolecules (such as proteins, peptides or genes) (Mehnert & Mader, 2001; Brigger, Dubert & Couvreur, 2002). Nanotechnology drug delivery systems have been reported in literature to offer useful strategies to overcome some of the problems associated with drug therapy such as (Mehnert & Mader, 2001) (a) insufficient drug concentration in the blood due to poor absorption, rapid metabolism and elimination; (b) poor drug solubility and bioavailability; (c) high fluctuation of plasma levels due to erratic bioavailability from oral administration. It has been mentioned that one in ten marketed drugs has solubility problems and close to a third fail to reach profitability due to poor bioavailability or pharmacokinetics (Knight, 2006). In drug delivery, small particles can aid in the direct entry of entrapped molecules into cells either passively (non-specifically) or actively via celltargeting ligands placed directly on the particle surface. The diameter of human cells is about 10–20 mmwhile the size of cell organelles ranges from