Parenteral Drug Delivery Systems: Injectables, Implants, and Infusion Devices

Parenteral DDS release drugs in a controlled manner through intravenous, intramuscular, or subcutaneous routes.

They include injectables, implants, and infusion devices.

Injectables include solutions and dispersions, microspheres, and nanoparticles.

Solutions control drug release via viscosity changes, complexation, or partitioning.

Dispersions, like emulsions and suspensions, use particle size and formulation to regulate drug release.

Microspheres use biodegradable polymer matrix to enable sustained delivery, especially for proteins and peptides.

Implants are surgically inserted devices for extended drug release and must be stable, biocompatible, and, sometimes, removable.

Infusion devices like osmotic pumps, vapor pressure systems, and battery-powered pumps deliver precise doses.

Osmotic pumps create pressure gradients using semipermeable membranes, vapor pressure systems rely on volatile fluids, and battery-powered pumps use electronics for timed delivery.

These systems enhance bioavailability, minimize side effects, and promote patient adherence through sustained release.