Long acting injectable formulation comprising risperidone and biodegradable polymers

A method of switching a subject from a daily oral risperidone therapy to a long acting injectable risperidone formulation, said method comprising:

• i. orally administering a final dose, i.e. a last dose, of the daily oral risperidone therapy, after which no further oral risperidone therapy is administered;
• and
• ii. the next day following the final dose of the daily oral risperidone therapy subcutaneously administering to the subject a first injectable dose of a long acting injectable risperidone formulation comprising:
• (a) risperidone, or a pharmaceutically acceptable salt thereof, at a concentration of about 250-400 mg/mL, equivalent to risperidone;
• (b) a biodegradable triblock copolymer having a formula:
• poly(lactic acid)v-poly(ethylene glycol)w-poly(lactic acid)x,
• wherein v and x are numbers of repeat units ranging from 24 to 682 and w is a number of repeat units ranging from 4 to 273 and v=x or v≠x;
• and,
• (c) a biodegradable diblock copolymer having the formula:
• methoxy-poly(ethylene glycol)y-poly(lactic acid)z,
• wherein y and z are numbers of repeat units, wherein y is a number of repeat units ranging from 3 to 50 and z is a number of units ranging from 7 to 327;
• and
• wherein a ratio of the biodegradable triblock copolymer of (b) and the biodegradable diblock copolymer of (c) is 1:3 to 1:8 or 1:1 to 1:19 or 3:2 to 1:19, in said formulation, which is insoluble in an aqueous environment;
• wherein the subcutaneous administration of the long acting injectable risperidone formulation results in a mean exposure of TAM (AUC0-tau) that is equivalent to that of oral risperidone (2 mg/day to 5 mg/day) administered over an equivalent dosing period;
• and
• wherein the long acting injectable risperidone formulation is administered once every two months and the method is implemented in the absence of a loading dose or supplemental oral risperidone or other antipsychotic drug;
• thereby switching the subject from a daily oral risperidone therapy to a long acting injectable risperidone formulation.