Implants Lecture Flashcards
Control Approaches
Use of viscous, water-misible vehicles
Use water-immiscible vehicles
Prep of water-insoluble drug derivative
-Dispersion in polymeric microspheres, microcapsules
Advantages
Reduce dose
Decrease side effects
Enhanced patient compliance
Improved drug utilizaiton
Implants
single unit DDS that are designed to deliver drug of a controlled rate over a prolong period of time
- Intended for sustained release
- Require specialized admin
Sites of implants
Loos interstitial tissue on upper arm
Anterior surface of the thing
Lower portion of the abdomen
Advantages of implants
Convience Compliance Controlled release Potential for intermittent release Bioresponsive release (controlled by endogenous substances)
Disadvantages of Implants
Invasive Termination by surgery Danger of device failure and overdose Limited to potent drugs ADRs Biocompatibility and produce immune response
Types of implants
Nondegradable polymeric implants
Biodegradable polymeric implants
Nondegradable polymeric implant
Silicones, Poly EVA, PVA
Biodegradable polymeric implants
Reservoir and matrix type
Polyanhydrides, PLA and PLGA
Vitrasert Intravitreal Implant
Nonbiodegradable PVA and EVA Eye Less than one hour Remove when depleted
Norplant
Nonbiodegradable
Contraceptive
Fan like pattern
Implanon
Birth control
Under arm
Last for 3 years
Zoladex Implant
PLA and PLGA
BIOdegradable
Treats endometriosis
Gliadel Implant
Biodegradable PA implant
Carmustine
Fatal brain cancer
Wafer degrades
Osmotic pumps
Semipermeable membrane (housing for entire pump and only allows water in) Osmotic chamber (holds osmotic agent) Reservoir wall (impermeable to water) Drug reservoir (drug solution) Flow moderator (exit route for solution)
Alzet Miniosmotic Pump
Osmotic pressure difference between a compartment called the salt sleeve and the tissue environment in which the pump is implanted
Controlled by water permeability
Duros Implant Pump
Piston between engine and drug reservoir to control flow
Regulated by membran’es control over the amount of water entering the pump and by the concentration of the drug in reservoir
Mechanical pump
Titanium because biocompatibile
Programmable to deliver drugs in zero order
Intrathecal Drug Pump
Pain pump
Direct to spinal cord
Slow release
Over a period of time at different time throughout the day
SynchroMed Implantable Pump
Programmable
Flexible dosage regimen
- Chemo, cancer pain, osteomyelitis
Insulin Pump
Composed of reservoir, battery operated pump, a computer chip
Insulin 24/7
Set at different basal rates to sink with lifestyle
Advantages to Insulin Pump
Eliminates injections Accurate delivery Reduces large influx Easier Flexible Improved quality of life Hypoglycemia reduced Eliminates unpredictability
Disadvantages
Weight gain
DKA
Expensive
Require hospital stay to learn
Minimed Insulin Pump
Deliver insulin
Piston pump drive the insulin through the catheter
Programmer can change pumping rate
Responsive to the need
