it depends on regulations pertaining to respective geographies/countries. where you operete and also where you supply...
for US ...YES,
in India, ...NO
for EU...not sure...
but I am not really sure if 3 batches are adequate...
whatever be the number...it ought to be supported by
1) suitable systematic assessment (viz., audits, trend of OOS / complaints at partners end...
2) criticality of materials to your product performance
3) !!! etc !!! need to back it up with your own procedures & its assessment of effectiveness of such reduced testing program.
4) you will also need to account for technical/logistic feasibility of particular analytical technique!!! (though this would not provide any marks in the quality/technical reviews...)
if you look at it,,, each one of points above needs to have specific-assessment criteria outlined in your procedures, and then have suitable review mechanisms built into your system to take care of roll-back as and when required...
hope this helps.