After the correct chemical has been scanned, the next step is to ensure the proper amount has been weighed out. With computer-scale integration, this step is easily achieved. The compounder will weigh out the proper amount of chemical being used and send that weight to the computer. If the weight is within a predetermined percentage (we use +/- 1%), the compounder is allowed to proceed and scan the next chemical. If the amount weighed varies outside of this +/- 1%, the computer warns the compounder the chemical will need to be re-weighed. In the past, we attached a printout of weights the compounder used to prepare the compound. The obvious limitation with this system is the impossibility to ensure which chemical was weighed at what amount. With computer-scale integration, you can be assured the correct chemical was not only used, but also weighed to the correct amount.