Side effects of a drug arise due to interactions of the drug to molecules other than the target.These effects of the,drug can be minimized by its high:
Specificity
Solubility
Affinity
Hydrophobicity
If a drug is more specific in action, it acts only in that paicular organ so no systemic side effects will be seen and targeted cancer therapy using nanopaicles is also bases on this approach Ref; KD Tripathi pharmacology 7 th edition (page no; 84)
General pharmacology