A Review on Parentral Implants

Implant is an object or material inserted into the body for prosthetic, therapeutic, diagnostic or experimental purposes. Implants are one of the dosage forms used to achieve effective concentration for long time. Implant dosage forms are useful for patients having difficulty in taking drugs orally, and it allows the avoidance of frequent dosage by sustained supply. Types of implants are insitu forming implant and solid implants. The rate of release of drugs from the implant is based on various mechanism i.e. diffusion controlled, chemically controlled, osmotically controlled, magnetically controlled. Compression, solvent association method, injection-molding, hot-melt extrusion these are the various process techniques have been used to prepared implant drug delivery system. Examples of implantable drug delivery devices are Norplant, compudose, Synchro-mate, Alzet osmotic pump, GLIADEL wafer implant, DURIN implants etc.