ABSTRACT
Loretz Brigitta,a Jain Ratnesh,a Dandekar Prajakta,a Thiele Carolin,a Yamada Hiroe,a Mostaghaci Babak,a Lian Qiong,b and Lehr Claus Michaela,ba Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Saarbrücken, Germanyb Department of Biopharmaceutics and Pharmaceutical Technology, Saarland University, Saarbrücken, Germany Brigitta.Loretz@helmholtz-hzi.de
purpose of this chapter. Herein we discuss the potential of carriers in the sub-micron dimension for advanced drug delivery. Physical and chemical properties, in particular solubility, permeability and chemical/biological stability are factors that may limit the bioavailability of a drug and consequently also the use in medicine/clinics. Highly potent actives can be discarded or delayed for such reasons. In general drugs can be classified in two groups, which also distinguish them in their degree of dependency on delivery systems. On the one hand there are chemically manufactured small molecules and on the other hand the so called biopharmaceuticals, which are macromolecules generated by means of biotechnological methods. Biopharmaceuticals comprise mainly protein and peptide drugs as well as nucleotide drugs. In case of small molecules, medicinal chemistry approaches sometimes can improve properties such as solubility, stability toward metabolic degradation or reduced toxicity in order to create more efficient agents. In cases where this is not possible formulations are needed to achieve efficient and safe pharmaceuticals. The term “drug delivery” implies a rather complicated process where the right concentration in time has to be achieved at the target location, ideally even with high specificity. In particular anti cancer drugs may benefit from targeted carriers to minimize the adverse effects in healthy tissue and maximize toxicity for cancer cells. In contrast, for biopharmaceuticals a delivery system is always required since their shared properties are large molecule size, structural complexity and fast metabolism. All these features hinder the achievement of sufficing bioavailability of the “naked” molecule. Biopharmaceuticals with their huge diversity however, are believed to realize personalized medicine to treat complex diseases with variable origin. But these new and highly promising drug candidates, originating from the enormous progress in genetics and biotechnology, are absolutely reliant on adequate delivery systems and technologies to exploit their therapeutic potential. In this regard medicine and pharmaceutical industry’s hopes are pinned on the emerging science of nanotechnology. This chapter provides an overview on currently investigated or unmet therapeutic needs, which could be opportunities for nanoscale delivery systems, summarize in brief the current arsenal of nanocarrier technologies and their ongoing translation into the clinics. Finally we discuss the challenges for developing future nanopharmaceuticals.
