1. Methods of Drug Delivery
Chapter 3
Methods of Drug Delivery

2. Delivery of Drugs Enteral – digestive tract
Parenteral – major route; Given into the cardiovascular circulation
Topical – by application onto the skin or associated membranes

3. Process of Drug Delivery
Drug Administration Phase – depends on form of med, speed medication action is needed, desired location
Enteral
Parenteral
Topical

4. Process of Drug Delivery
Pharmacokinetic Phase – movement of drugs throughout the body to various targets
Absorption
Distribution
Metabolism
Excretion

5. Process of Drug Delivery
Pharmacodynamic Phase – drugs produce a change or an effect at a specific target (receptor)
Efficacy
Potency

6. Physical Properties
Influence how medications enter and move throughout the body

7. Physical Properties
Solids – most effective via a body opening, need to dissolve first to become active, which slows the process

8. Physical Properties
Liquids- move quicker through the body but need to penetrate the cellular membrane, viscosity can make it more difficult if it is higher, solubility the ability to dissolve will affect how easily it passes across the membrane

9. Physical Properties
Hydrophobic- dissolve in lipids, work better penetrating body membranes

10. Physical Properties
Hydrophilic – dissolve in water, work better in the bloodstream

11. Physical Properties Gas
Fast absorption, moves quicker to target area and action is in seconds

12. Oral Route
By mouth
Can be chewed, swallowed, or dissolved in the mouth
Tablets, capsules, powders, solutions, suspensions
Dissolution delays the onset of action, water is needed or may be taken with food

13. Sublingual Absorbed quickly into the bloodstream
Avoid the first- pass effect –intestinal absorption into the portal circulation to the liver to be metabolized by the liver

14. Rectal
Use with unconscious patients, patients with N/V, infants not able to swallow pills
Rapid onset of action due to blood supply

15. Injection Into the Blood VesselsIV
Bolus
Infusion
Bypasses destructive enzymes of GI tract and the liver
Fluid overload, infection

16. Injections Intradermal dermis easily absorbed Subcutaneous hypodermis
Intramuscular muscles
faster onset of action

17. Injections Advantage IM and subcutaneous
Concentration of drug is predictable
Confined to a precise location
May be given to unconscious patients and children
Disadvantage IM and subcutaneous
Pain, swelling, tissue damage, infection

18. Injections
Intrathecal directly in spinal subarachnoid space(dorsal spine spinal cavity beneath a sheath surrounding the spinal cord called the anrachnoid mater) spinal anesthetics or medications that might enter the cerebral spinal fluid

19. Injections
Epidural directly into a space overlying the dura mater (most superficial layer of that protects the CNS)

20. Injections
Intraperitoneal directly into the abdominal cavity

21. Injections
Into the joint spaces (analgesics and anti- inflammatory drugs)

22. Topical Skin Eyes Ears Nasal membranes Reproductive openings
Effect is systemic or local

23. Transmucosal Drugs Cross membrane lining Respiratory
Reproductive tracts
Effect: systemic or local
Forms: suppositories, sprays, mists, foams, aerosols, volatile agents
Examples: asthma, vaginal infections

24. Ears and Eyes
Eyes
Effect: to lubricate, prevent inflammation or treat infections of the cornea
Forms: ointments, salves, or drops
Ears
Effect: to treat infections, cerumen buildup
Forms: drops ( need to penetrate the ear canal and middle ear to be effective)

25. Client Teaching Oral: take with water or food to reduce nausea
Establish a routine
Follow dosing times, do not play catch up
Store medication in a dry safe place
Discard outdated medications
Take medications with calibrated insert provided

26. End