Vol 8, Issue 4, 2015 ISSN - 0974-2441 A REVIEW ON RESEALED ERYTHROCYTE AS A NOVEL DRUG DELIVERY SYSTEM SELVAMANI P*, LATHA S, MONISHA S, SUPASSRI T Department of Pharmaceutical Technology & Centre for Excellence in Nanobio Translational Research, Anna University, Bharthidasan Institute of Technology, Tiruchirappalli - 620 024, Tamil Nadu, India. Email: pselvamani@hotmail.com Received: 29 March 2015, Revised and Accepted: 05 May 2015 ABSTRACT Cellular carriers possess great potential and merits in various modules of drug delivery. Among such cellular carriers, erythrocytes have been found to possess huge merits for the targeted and controlled drug delivery since they are non-immunogenic, non-toxic and their circulation can be readily controlled and could be manipulated with reference to time. Erythrocytes mediated drug delivery has been reported with therapeutic enzymes and antiviral agents to maximize therapeutic performance, reduce the side effects, as circulating depots for controlled drug release, drug targeting, treatment of parasitic diseases, hepatic tumors, removal of toxic agents etc. In this review, isolation of carrier erythrocytes, methods of drug loading, characterization parameters methods and clinical applications of resealed erythrocytes were presented. Keywords: Resealed erythrocyte, Drug targeting, Controlled release, Carrier mediated drug delivery system. INTRODUCTION Drug delivery is the method of formulation, technology or systems for transporting an active pharmaceutical ingredient to the target receptor at an organ in the body without any loss or compromise in the chemical integrity of the molecule and could be manipulated to effect the desired pharmacological action. Drug delivery technology plays around modification and improvement of various pharmacokinetic parameters such as drug release profile, absorption, distribution, and elimination, etc. The substances that are used to transport the drug to the target site were called as drug carriers and should aid the drug to prolong its in vivo actions, decrease metabolism, eliminates toxicity and with tailored pharmacokinetic parameters [1]. Drug carriers are substances that serve as transporters to deliver the drugs to target and improve the effectiveness of drugs. New drug delivery systems have been developed to overcome the limitations associated with the conventional drug delivery systems in order to improve the patient compliance and safety. They may be classified based on their size as (i) microcarriers for example, Liposomes, resealed erythrocytes, microspheres (ii) nanocarriers for example, niosomes, pharmacosome, aquasomes, nanoparticles, solid lipid nanoparticles (SLN), miscelles (iii) variable carriers for example, dendrimers. Liposomes are a form of vesicles that consist either of many, few or just one phospholipid bilayers. The polar character of the liposomal core enables polar drug molecules to be encapsulated. Thus, drugs that are encapsulated in a nano cage-functionalized with channel proteins are effectively protected from premature degradation by proteolytic enzymes. Resealed erythrocytes are prepared by the delivery of drugs and drug-loaded microspheres into the Erythrocytes, have been extensively studied for their potential carrier capabilities. Such drug- loaded carrier erythrocytes are prepared simply by collecting blood samples from the organism of interest, separating erythrocytes from plasma, entrapping drug in the erythrocytes, and resealing the resultant cellular carriers. Hence, these carriers are called resealed erythrocytes. Microsphere is characteristically free flowing powders consisting of proteins or synthetic polymers which are biodegradable in nature and ideally having a particle size <200 µm. It is the reliable means to deliver the drug to the target site with specificity if modified, and to maintain the desired concentration at the site of interest. Pharmacosomes are colloidal dispersions of drugs covalently bound to lipids, and may exist as ultrafine vesicular, micellar, or hexagonal aggregates, depending on the chemical structure of the drug-lipid complex. It is based on the principle that the drug binds covalently to a lipid where the resulting compound is the carrier and the active compound at the same time. Aquasomes are one of the most recently developed delivery system for bioactive molecules like peptide, protein, hormones, antigens and genes to specific sites. They are spherical in shape with 60-300 nm particles size. Nanoparticles (including nanospheres and nanocapsules of size 10- 200 nm) are in the solid state and are either amorphous or crystalline. They are able to absorb and/or encapsulate a drug, thus protecting it against chemical and enzymatic degradation. Biodegradable polymeric nano particles have attracted considerable attention as potential drug delivery devices in view of their applications in the controlled release of drugs, in targeting particular organ/or tissue, as carriers of DNA in gene therapy, and in their abilities to deliver proteins peptides and genes through peroral route. SLN are at the forefront of the rapidly developing field of nanotechnology with several potential applications in drug delivery and research. Due to their unique size-dependent properties, lipid nanoparticles offer the possibility to develop new therapeutics. The ability to incorporate drugs into nanocarriers offers a new prototype in drug delivery that could use for drug targeting. Micelles formed by self-assembly of amphiphilic block copolymers (5-50 nm) in aqueous solutions are of great interest for drug delivery applications. The drugs can be physically entrapped in the core of block copolymer micelles and transported at concentrations that can exceed their intrinsic water-solubility. Dendrimers are nanometer-sized, highly branched, and monodisperse macromolecules with symmetrical architecture. They consist of a central core, branching units, and terminal functional groups. Targeting effectiveness is affected by attaching targeting ligands at the external surface of dendrimers, while their stability and protection Review Article