Drug Targeting Research Paper

SITE SPECIFIC DRUG DELIVERY Site specific delivery systems are unique forms of delivery systems whereby the drug or medicine is specifically or selectively delivered to a particular site in the body where it is going to exert it's action and it is not delivered to other non-target organs and cells. The main aim of site specific delivery of drugs is to develop drug concentration that is sufficient to produce therapeutic effect at the site of the disease with minimal effect to the rest of the organs, tissues and cells of the body. These site specific drug delivery systems act on a particular disease or anatomical area or organ to produce the desired therapeutic effect. For the drug to be delivered to a specific site there has to be a carrier,

Passive targeting : Drug delivery systems which are targeted or aimed to the systemic circulation are known as passive delivery systems. In passive targeting the drug is administered as a pro drug or inactive form which gets activated once it comes into contact with the site or tissue. In cancer therapy, passive target systems have the ability to differentiate between normal cells and tumor cells thereby reducing damage to other cells and tissues.

2. Inverse targeting: Inverse targeting is where by the drug is targeted to avoid or bypass uptake by the reticuloendothelial system. The reticulo endothelial system function is reduced by administering large amount of blank colloidal carrier systems such dextran sulphate . By injecting this colloidal carrier, it binds to the reticulo endothelial system instead and therefore saturating the binding sites leading to the drug been redirected to organs outside the reticuloendothelial

They may also be prepared from amphiphilic ionic molecules which are negatively charged or positively charged stearylamine. Niosomes are very much like liposomes in their physical characteristics but they differ in their chemical compositions. Niosomes in the form of micelles or vesicles can be used as carriers for the transport of drugs such as anticancer and topical preparations. Anticancer niosomes do accumulate in tumor cells and are mostly taken up by the liver therefore they can be used as drug delivery vehicles to the liver and spleen. Antigens were formulated as niosomes in water in oil emulsions which increases the activity of the antigens due it's controlled release