ISSUE OF C FORM ON THE PURCHASES OF RMPM

Please suggest whether we can issue "C form" against purchase of raw materials and packing materials which are used in the  manufacture of finished product which is NOT FOR SALE. Eg. Physician Sample manufactured along with regular pharmaceutical products.  Since physician sample is distributed free of cost to the doctors (not sold), is there any restriction in CST ACT to issue C form to the corresponding purchases?.  Again where the purchase of RMPM can not be allocated seperately to manufacture of physcian sample (where total purchases are made for manufacture of pharamaceutical products as well as physician samples), whether issue of C form voilate any CST Provisions?  Please Give your openion with appropriate section/provision of CST ACT.