drug administration , absorption , distribution , factors ,

1. 1

2.  Absorption - involves the passage of the drug from its
site of administration into the blood
 Distribution - involves the delivery of the drug to the
tissues and organ.

3. ROTES OF ADMINISTRATION

4. Factors which influence the rate of
absorption
 routes of administration.
 dosage forms.
 circulation at the site of absorption.
 concentration of the drug.

5. Topical
 When a drug is applied directly to the skin or the eyes or
ears, it is administered via the topical route .
 The therapeutic effect of the drug only extends to the local
area.

6. OCULAR DRUG DELIVERY
 Many of disease states affect different sites within the eye.
 Highly effective therapeutic agents have been developed for the
treatment of
various ocular diseases.
 A eye drops dose is also lost by protective mechanisms, such as solution
drainage

7. Forms
 The topical route of administration is used to treat
diseases that affect the eye.
 - Solutions.
 - Colloids.
 - Emulsions.
 - Suspensions.
 - Ointments.
 - Solid hydrophilic inserts.
 - Therapeutic contact lenses.

8. Suspensions
 They provide slow dissolution and prolonged release
of drug.
 The particle size is generally less than 10 um in
diameter.
 Steroids are frequently administered in the form of
suspensions.

9. Ointments
 Ointments contain one or more Mineral oil , Polymers
 Drugs administered as ointments have better
bioavailability than drops.

10. Ocular Inserts
 An ocusert is a system for controlled release ocular
drugs.
 An ocusert is an insoluble ophthalmic insert that
releases drug at a constant rate for a prolonged period
of time, and minimize
 drug reservoir

11. Properties of an ideal Ocuserts
 a) Comfort
 b) Ease of Handling and insertion
 c) Not interfere with vision
 d) Stable, and inert
 e) Applicable to a variety of drugs

12. ADVANTAGES
 Increased contact time and thus improved bioavailability.
 reduced systemic adverse effects.
 Administration of an accurate in the eye and thus a
better therapy Possibility of targeting
 Easy enough for self-administration.

13. DISADVANTAGES
 Systemic drug absorption.
 Drug binding to tear proteins.
 corneal fluid drainage.
 Melanin binding.
 Drug metabolism(ENZYME).

14. Contact Lenses
 For vision correction.
 often used to aid in corneal wound healing
 in patients with infectious corneal ulcers.
 rapid release drug delivery as antibiotics, anti-
glaucoma agents

15. Nasal route
 Nasal administration involves spraying a drug into the
nasal cavity. This is usually done
 Topically to treat allergy symptoms of nasal

17. Forms
 Applied by:
 drops (instillation)
 sprays
 aerosol (spray under pressure)
 Used for:
 relief of nasal congestion or allergy symptoms
 administration of flu vaccine

18. ADVANTAGES
 The effect is often reached within 5 min.
 used as an alternative to oral administration of for
example tablets and capsules.
 Drugs which show poor absorptivity.

19. DISADVANTAGES
 limited volume can be sprayed.
 risk of harmful long-term effects .
 sensory irritation of the nasal
mucosa.

20. Enteral Routes
 Enteral - drug placed directly in the GI tract:
 sublingual - placed under the tongue
 oral - swallowing (p.o., per os)
 rectum - Absorption through the rectum

21. First-pass Effect

22. BUCCALROUTE
 Buccal or sublingual dosage form enable drugs to be taken as smaller
tablets held in the mouth or under the tongue.
 Buccal tablets are often harder tablets [4 hour disintegration time],
designed to dissolve slowly.
 Nitroglycerin, as a softer sublingual tablet [2 min disintegration time] may
be used for the rapid relief of angina.
 This ROA is also used for some steroids nicotine-containing chewing
gum

24. Buccal
 Advantages
 rapid absorption
 drug stability
 avoid first-pass effect
 patients who are unable to swallow.

25. Buccal
 Disadvantages
 Dilution of drugby GI fluid.
 small doses
 unpleasant taste of some drugs
 Holding the dose in the mouth may be inconvenient.

26. Forms
 Chewingum.
 Tablet.
 Mouthwash.
 Ointment.

27. RECTAL ROUTE
 Absorbed by the rectum blood vessels and flow into the
body circulatory system, which distributes the drug to the
body organs.

28. METHODS
 enema -cleansing the bowel
 suppository-solid dose form formulated to melt in the
rectum at body temperature and release the active drug
 Ointment.

29. DISADVANTAGES
 They are not preferred by patients they are
inconvenient.
 Rectal absorption of most drugs is frequently
erratic and unpredictable.
 Some suppositories "leak" or are expelled after
insertion.

30. • Unconscious patients and children.
• If patient is nauseous or vomiting.
• Easy to terminate exposure faster onset high bioavailability.
• Irritating drugs contraindicated.
ADVANTAGES

31. Topical
•Mucosal membranes (eye drops, antiseptic, sunscreen,
nasal, .)
•Skin
>Dermal - rubbing in of oil or ointment(local action)
>Trans dermal - absorption of drug through skin
(systemic action)

33. Tran dermal route

34. Epidermis
Dermis
tissue
Muscle

35. Trans dermal route
 This involves administration of the drug dose just under the
skin.
Or
 delivers drug to bloodstream via absorption through the
skin.

36. Transdermal patches
 Systemic effect .
 Specific dose contained on patch .
Form

38. Advantages
•Can be given by patient, e.g. in the case of insulin
•Absorption slow but usually complete.
•Absorption rate can be improved by massage or heat.

39. Disadvantages
 Can be painful
 Irritant drugs can cause local tissue damage
 Maximum of 2 ml injection thus often small
doses limit use.
 Not effective inan emergency

40. pulmonary Medications
 delivers medication directly into the lungs via the mouth
 Some devices use a powder or nonaerosolized spray for
inhalation instead of compressed gas
 commonly utilized for young children or elderly patients
with asthma or lung disease

42. Nebulizer
42
medication is delivered into the lungs through an
apparatus that uses compressed air. The medication is
placed into the cup of the device and connected to the
machine that produces a mist that is inhaled by the person

44. DISADVANTAGES
 The absorption enhancer used to improve nasal
delivery system may have toxicity.
 Absorption surface area is less (GIT)
 Ones drug administerdcan’t be removed
 Nasal irritation.

45. Advantages
 Drug degradation is absent.
 Rapid drug absorption.
 Quick onset of action.
 1st pass metabolism is absent.

46. APPLICATION
 Local delivery.
 Systemic delivery.
 Nasal vaccines.

47. Thank you