In this paper, we deal with the problem of tracking a desired plasma glucose concentration by means of intravenous insulin administration, for Type 2 diabetic patients. A nonlinear time-delay model is used to describe the glucose-insulin regulatory system, according to which a model-based approach is exploited to design a semiglobal sampled-data dynamic output feedback controller. It is shown that emulation, by Euler approximation, of a proposed continuous-time control law yields stabilization in the sample-and-hold sense of the glucose-insulin system. The glucose regulator makes use of only sampled glucose measurements. Theoretical results are preclinically validated through a virtual environment broadly accepted as a substitute to animal trials for the preclinical testing of control strategies in plasma glucose regulation. Numerical results are encouraging and pave the way to further clinical verifications.