Drug Carriers

In recent years, there has been an exponential interest in the development of novel drug delivery systems using drug carriers. Drug carriers offer significant advantages over the conventional drug delivery systems in terms of high stability, high specificity, high drug loading capacity, controlled release of drug and ability to deliver both hydrophilic and hydrophobic drugs. As a result of their unique behaviors, drug carriers have a wide range of biomedical and industrial applications. Nanospheres are associated with a lot of benefits such as ease of administration to target sites, reduction in toxicity level and ease of passage via the capillary vessels. Hydrogel nanoparticles are useful in the treatment of inflammatory diseases, as bioresponsive hydrogels in drug delivery system and as a carrier in controlled drug delivery system.  Carbon nanotubes have a large surface area which has the ability to adsorb or conjugate with a wide variety of therapeutic and diagnostic agents. They are useful in the areas of gene delivery, tissue regeneration and biosensor diagnosis. Liposomes are known to target a drug to a specific site. They entrap drugs which are released for subsequent absorption. They are used to achieve active targeting, increase efficacy and therapeutic index of drugs. Niosomes improve the solubility and oral bioavailability of poorly soluble drugs. They protect drugs from biological environment, increase the stability of entrapped drugs and they can easily reach the site of action. Aquasomes are nanoparticulate carriers that can be characterized for structural analysis. They preserve conformational integrity and biochemical stability of drugs. Ethosomes are noninvasive delivery carriers that enable drugs to reach the deep skin layers and the systemic circulation.  They contain phospholipids which could be in form of phosphatidyl choline (PC), hydrogenated PC, phosphatidic acid (PA), Phosphatidyl serine (PS) and phosphatidyl inositol (PI). Ethosomes are known to increase skin permeation of drugs, improve biological activity and pharmacodynamics profile of drugs. This review aims to emphasize the importance of drug carriers in drug delivery system, and applications of drug carriers in various areas of research, technology and treatment.