METHODS	Single microneedles with lengths ranging from 480 to 1450 microm , widths from 160 to 465 microm , thicknesses from 30 to 100 microm , and tip angles from 20 to 90 degrees ; and arrays containing 5 or 50 microneedles were inserted into the volar forearms of 10 healthy , human volunteers in a double-blinded , randomized study .\