Rapid establishment and/or termination of substantial steady-state drug delivery

A method of treating type 2 diabetes mellitus in a subject in need of treatment, comprising:

• providing continuous delivery of exenatide from an osmotic delivery device, the osmotic delivery device comprising
• an impermeable reservoir comprising interior and exterior surfaces and first and second open ends,
• a semi-permeable membrane in sealing relationship with the first open end of the reservoir,
• an osmotic engine within the reservoir, the osmotic engine adjacent the semi-permeable membrane,
• a piston adjacent the osmotic engine, wherein the piston forms a movable seal with the interior surface of the reservoir, the piston divides the reservoir into
• a first chamber and a second chamber, the first chamber containing the osmotic engine,
• a suspension formulation contained in the second chamber, the suspension formulation comprising a particle formulation and a vehicle formulation, wherein
• the particle formulation comprises particles comprising exenatide in particles of less than 10 microns in diameter, and
• the vehicle formulation comprises a solvent and a polymer, wherein the solvent is selected from the group consisting of benzyl benzoate, lauryl lactate, and lauryl alcohol, and the polymer is polyvinylpyrrolidone, the vehicle formulation having a viscosity between about 10,000 poise and about 20,000 poise at 37° C., and
• a diffusion moderator that defines a delivery orifice inserted in the second open end of the reservoir, the diffusion moderator adjacent the suspension formulation;
• wherein (i) substantial steady-state delivery of the exenatide at a therapeutic concentration is achieved within a time period of 5 days or less after implantation of the osmotic delivery device in the subject, and (ii) the substantial steady-state delivery of the exenatide from the osmotic delivery device is continuous over an administration period of at least about 3 months at a mcg/day dose of exenatide selected from the group consisting of about 10 mcg/day, about 20 mcg/day, about 30 mcg/day, about 40 mcg/day, about 60 mcg/day, and about 80 mcg/day.