APPROACHES TO TARGETED DRUG DELIVERY SYSTEM:
A) Pro-drug :
A prodrug is pharmacologically inert form of an active drug that must undergo transformation to the parent compound in vivo by either chemical or an enzymatic reaction to exert its therapeutic effects.
B) Drug Carrier Delivery System:
Drug-carrier delivery systems employ biologically inert macromolecules to direct a drug to its target site in the body.
These are divided into two types: Particulate and soluble macromolecular. Depending on the carrier system, the drug can either be molecularly entrapped within the carrier matrix or covalently linked to the carrier molecules.
The major advantage of drug-carrier delivery systems is that the distribution of drug in the body depends on the physiochemical properties of the carrier not those or by alterations in the physiochemical properties of the carrier. There are however several other factors that must be considered in the pharmaceutical development and clinical use of both soluble macromolecular and particulate bio-technical and synthetic site-specific systems.