A beneficial agent present in the devices is released at a controlled rate and in {TAIL ~ effective amounts} as the polymers erode over {HEAD ~ time} 
A beneficial agent present in the devices is released at a controlled rate and in { TAIL ~ effective amounts } as the polymers erode over { HEAD ~ time }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD