ABSTRACT
Noha Nafee Department of Pharmaceutics, Alexandria University, Alexandria, Egypt
and Biopharmaceutics and Pharmaceutical Technology, Saarland University,
Saarbriicken, Germany
Vivekanand Bhardwaj Department of Pharmaceutics, National Institute of Pharmaceutical
Education and Research (NIPER), S.A.S. Nagar, Punjab, India and
Biopharmaceutics and Pharmaceutical Technology, Saarland University, Saarbriicken, Germany
Marc Schneider Pharmaceutical Nanotechnology, Technology, Saarland University,
Saarbriicken, Germany and
Biopharmaceutics Technology, Saarland University, Saarbriicken, Germany
Inherently, as the word already antIcIpates, biological barriers are designed to effectively protect organisms from any kind of alien material. At the same time this strongly limits the use of active substances. This holds especially for modem macromolecular drugs produced by biotechnological techniques which are especially powerful. Unfortunately, most of these drugs lack necessary properties such as stability and solubility as well as their potential to cross biological barriers is small [Alonso, 2004; Pardridge, 2006]; resulting in a weak pharmacokinetic profile [Hidalgo, 2001]. Carrier systems offer an essential advantage in protecting these active substances against degradation and metabolism as well as in modifying the interaction with biological material. Nucleic acids (plasmid DNA and antisense oligonucleotides) are a prominent example of substances that are not able to be delivered to the target site in the body without a suitable carrier. The need for specifically tailored and adapted carrier systems was already pointed out in the advent of gene therapy [Bianco, 2004; Verma and Somia, 1997].
