Nanoparticles in Drug Delivery

Abstract

Drug delivery is the study which deals with processes and methods of administering drugs and other pharmaceutical compounds to achieve the best therapeutic effect in humans or animals. Conventional administrations of drugs have several problems associated with it. The unaltered drug is given through the mouth (orally), nose (nasally) or through injection directly into the blood stream. Problems associated with these methods are poor distribution, large dosage requirements, side effects on other cells, drug degradation, cell rejection and other problems. Rather than administering the unaltered drug directly, we can change some of the drug’s properties or administer it in some other ways. Nanoparticles (called nanocarriers) show great potential as drug delivery systems. The drug or compound is altered by combining or encapsulating it with nanoparticles. How the properties are altered depends on the type, shape and size of the nanoparticles used. Improving safety efficacy ratio of drugs has been attempted using different methods such as individualizing drug therapy, dose titration, and therapeutic drug monitoring. Delivering drug at controlled rate, slow delivery, targeted delivery are also very attractive methods. It can be specialized for anticancer treatments, brain targeting, lung targeting and so on. The types of nanoparticles used are: Liposomes, solid lipids nanoparticles, dendrimers, polymers, silicon or carbon materials, and magnetic nanoparticles. Magnetic Nanoparticles (MNPs) are metallic nanoparticles that are controlled by an external magnetic field after it is administered to the patient. Magnetic nanoparticles exhibit a wide variety of attributes, which make them highly promising carriers for drug delivery. They are divided into the categories of pure metals (Mn2+ etc), their alloys and oxides. Presently, only iron oxide nanoparticles (e.g.Fe2O3) are approved for use due to their favourable properties. MNPs There are many drawbacks and limitations to current nanoparticulate drug delivery. Despite all these problems, nanoparticle DDS which respond to slight changes in the local cellular environment have a potential to resolve many of the current drug delivery problems. Nanoparticles can be used in a multifunctional way to not only deliver drugs but also to mark abnormal cells for future therapy. But before nanoparticle drug delivery becomes possible, challenges which include developing toxicity testing protocols, improving biocompatibility, drug loading, targeting, transport and release, controlling interaction with biological barriers, detecting and monitoring exposure level and assessing the impact on the environment have to be met. Problems of the limitations of current technology and techniques also must be overcome. Most importantly, a generalized method for creating nanoparticles must be developed with the aim of manufacturing biocompatible and non-toxic drug delivery systems. If these challenges are met and the problems overcome, the potential for nanoparticulate drug delivery is immense. Unique solutions can be used to cure cancers, HIV and many diseases. At the same time the treatments will be more cost effective and affordable to the general public. Not only can treatments be improved but also medical knowledge can be increased as nanoparticles are used for diagnostic applications. Also consider the magnetic targeted drug delivery system. It is one of the most attractive strategies in targeted therapy. Magnetic nanoparticles have their unique magnetic properties and they can be attracted by magnetic fields, thus, acting as drug carriers in a target therapy.