 Specific Aim 1: To examine whether co-formulation rHuPH20 with analog insulin INS-PH20or, alternately, pre-administration of rHuPH20 PH20-preRx at the time of infusion set placement prior to initiation of closed-loop CL insulin delivery will reduce peak-postprandial glucose concentrations and total glucose area under the curve of the meal excursions in short term inpatient experiments. 