<qa>  What is the name of the study that will comprise two dosing periods?The study will comprise two dosing periods in two different cohorts of healthy volunteers. The investigators will begin with a single dosage period I 1 injection of 25 mg of Risperidone for each subject; single dosage period II, different from the previous one 1 injection of 37.5 mg of Risperidone for each subject, in a second group of healthy volunteers different from the first group will not start until after a preliminary analysis has been made of the safety data and plasma concentration data are known for the formulation of prolonged release Risperidone using the ISM technology. 