Pharma Admission


pharma admission




Pandey Noopur*, Mahara Kamal
Department of Pharmaceutics
Global Institute of Pharmaceutical Education and Research,
Kashipur, Dehradun,
Himachal Pradesh, India

Dendrimers are macromolecules having highly branched, 3 D structure, nano scale architecture with monodispersity and high functionality. These properties make it attractive candidates as unique and optimum drug carriers for controlled release or targeted delivery. Dendrimer is a smart polymer and as a result of their behavior dendrimers are suitable for a wide range of biomedical and industrial applications and in medical applications such as drug delivery, tumor therapy, diagnostics etc. The field of dendrimers has recently emerged as the most commercially viable technology of this century because of its wide ranging potential applications in many fields such as: healthcare, electronics, photonics, biotechnology, pharmaceuticals, drug delivery, catalysis and nanotechnologies. The review aims mainly on the introduction, objectives, properties, synthesis and applications, in future aspects of dendrimers. Dendrimers help in achieving increased bioavailability, sustained, controlled and targeted release of drug. Thus present review focuses on the fundamentals of dendrimers and their use as drug delivery agents in treatment of disorders.

Reference Id: PHARMATUTOR-ART-2531

PharmaTutor (Print-ISSN: 2394 - 6679; e-ISSN: 2347 - 7881)

Volume 5, Issue 10

Received On: 24/06/2017; Accepted On: 24/06/2017; Published On: 01/10/2017

How to cite this article: Pandey N, Mahara K; Dendrimers: A novel carrier for drug delivery system; PharmaTutor; 2017; 5(10); 48-54

Dendrimers formulation of delivery is one of the most challenging attractive research areas for pharmaceutical scientists. The use of nonionic or ionic biodegradable polymers in aqueous solutions and colloidal dosage forms such as liposomes, nanoparticles, microspheres, microemulsions, resealed erythrocytes, microcapsules and dendrimers have been studied to overcome the drug delivery problems and improve the site targeting as well as release rate and side effect. Dendrimers as a drug delivery agent is a promising, safe, effective and selective drug delivery option. This review covers a few basic information of dendrimers preparation method and more about their possible application in various areas such as biomedical field, therapeutic agent, diagnostic agent, gene transcription, targeted drug delivery, solubility enhancer, catalyst, additives, printing ink, biomimics and many other areas of science. The dendrimers applications on biomedical field show high progress in future of dendrimers

The term ‘dendrimer’ originated from Greek word Dendron, meaning tree and meros meaning part. Dendrimers are characterized by its highly branched 3 D structure that provides a high degree of surface functionality and versatility. Dendrimers have a high degree of molecules uniformity, narrow molecular weight distribution, specific size and shape and highly functional terminal surface. Dendrimers have after been referred to as the “polymers of 21st century”. Dendrimer chemistry was first introduced in 1978 by Fritz Vogtle & Coworkers. He synthesized the first ‘cascade molecules’. Dendrimers is mainly act as carrier in solubilization applications, delivery of DNA and oligonucletide, targeting drug at specific receptor site. Dendrimers are being considered as additives in several routes of administration including intravenous, oral, transdermal, pulmonary and ocular. Dendrimers can work as a useful tool for optimizing drug delivery of such problematic drugs with reduced cost of its production and enhance the solubility, bioavailability and permeability. Due to their multivalue and monodisperse character, dendrimers have stimulated wide interest in the field of chemistry and biology, especially in applications like drug delivery, gene therapy and chemotherapy [1].

Concept of Dendrimers
Dendrimers are built from a starting atom such as nitrogen, to which carbon and other element are added by a repeating series of chemical reaction to produce a chemical branching structure. Dendrimers become densely packed as they extend out to the periphery, which forms a closed membrane like structure. As the process repeats, successive layers are added and the spheres can be expanded to the size required by the investigator. The result is a spherical macromolecular structure similar to albumin and globulin.

Dendrimers possess distinguished architectural components.
1. An initiator core
2. Interior layers (generations) composed of repeating units radially attached to the interior core.
3. Exterior (terminal functionality) attached to the outermost interior generations.

Figure1: Schematic representation of a generation 2 dendrimer [2]

Dendrimers which are lower generation (0, 1 and 2) have highly asymmetric shape and possess more open structure as compared to higher generation dendrimers. As the chain growing  the core molecule become larger and more branched (4 and higher generations) dendrimers adopt a globular structure.
Dendrimers become densely packed as they extend out to the periphery, which forms a closed membrane like structure. When a critical branched state is reached dendrimers cant grow because of lack of space. This is called the ‘Starburst effect’[3]

Figure2: Dendritic box encapsulating guest molecules [4]

The purpose of dendrimers is to improve the oral drug delivery because of the oral drug delivery is the most popular and has received more attention in the pharmaceutical field because of ease of production, low cost, conversion of ease of administration and flexibility in designing of dosage. Thus the dendrimeric formulation is possible and effective for the oral drug delivery. Dendrimers provide unique solution to complex delivery problems for ocular drug delivery. The recent problems for ocular drug delivery focus on increasing the residence time of pilocarpine in the eye was overcome by using PAMAM dendrimers with carboxylic and hydroxylic surface groups. These surface modified dendrimers were predicted to enhance pilocarpine bioavailability. So in overall the main objective of the dendrimer formulation is to provide the safe and effective therapy, to overcome the site specific targeting, easy production and low effective cost. Improve the pharmacokinetic and pharmacodynamics properties of a drug so that there is also acceleration in bioavailability [5].

Objectives of Dendrimers formulation
The main objective of the Dendrimer formulation is to improve the efficacy, effectiveness and safety of the drug. Dendrimers have ideal properties which are useful in targeted drug delivery system. One of the most effective cell specific targeting agents delivered by dendrimer is folic acid PAMAM dendrimers modified with carboxy methyl PEG 5000 surface chains revealed reasonable drug loading, a reduced release rate and reduced haemolytic toxicity conferred with the non-PEGylated dendrimer. To prepare sustained/ Prolong delivery of therapeutic agent in targeted drug delivery system so minimize the patient compliance and decrease of hepatic first pass and chemical degradation in the gastrointestinal tract. Dendrimers are suitable for intravenous/intraperitonial route. This route is the rapidest and simplest method for drug delivery into the systemic circulation. In the oral delivery system of the drug improves patient compliance especially in the patient option. Dendritic polymers are analogous to protein, enzymes and viruses so the good scope of dendrimer in the biomedical fields.
The other objectives of the dendrimer is the diagnostic reagent for tumor imaging by magnetic resonance imaging and as contrast agent, by varying the size hydrophilicity and by combining with tumor targeting antibodies. These compounds can be used for a range of specific imaging purpose [6].



Subscribe to Pharmatutor Alerts by Email