[ABA2015]

hi
as you know nano capsules are used as one of new ways for drug delivery, I think mostly in anti cancer drugs (am I right? ) but here my main questions are:

1- is it applicable for all kinds of drugs or the drug must have some specific properties, for example for the drugs with poor solubility in water, the salt form of them can help for better drug delivery and so many examples like this...
2- how a nano capsules are prepared for the synthesized drugs? and is the preparation process expensive?