Nano suspensions have gained great interest in 
the last decade as a formulation tool for poorly soluble 
drugs. By decreasing particle sizes nano suspensions 
enhance dissolution rate and bioavailability of the drug. 
Recently, nanoscale systems have received much interest 
as a way to resolve solubility issues because of their cost
effectiveness and technical simplicity compared to 
liposomes and other colloidal drug carriers. They have 
also been used for drug targeting. Formulation of 
lipophillic drugs into nano suspensions improves their 
stability 
and also enhances their bioavailability 
significantly. Nano suspensions have unique advantages 
for which they have been utilized for the production of 
dosage forms suitable for administration through oral, 
parenteral,
 ocular 
and 
pulmonary routes. Nano 
suspensions can be manufactured using the ‘Top Down’ or 
‘Bottom’s Up’ technology and employ a variety of 
components including surfactants for stability purposes 
and polymers for sustained release of drug in certain 
formulations. This paper reviews recent patents, methods 
of preparation and marketed products with their 
importance or status, novel researches and characterization 
implemented till date to overcome the challenges in poorly 
water soluble drugs.