Route of administration and implication on bioavailability

BIOAVAILABILITY

It is defined as the rate and extent of absorption of unchanged drug from it’s dosage form.

1. Route of administration and implication on bioavailability Department of Pharmacy (Pharmaceutics) | Sagar savale Mr. Sagar Kishor savale [ Department of Pharmaceutics] [email protected] 2015-016

2. CONTENTS INTRODUCTION OBJECTIVE BIOAVALIBILITY FACTORS AFFECTING SELECTION OF ROUTES OF ADMINISTRATION CLASSIFICATION OF ROUTES OF ADMINISTRATION IMPLICATION ON BIOAVALIBILITY 2 Sagar Kishor Savale 4/27/2016

3. INTRODUCTION 1,2 Dosage form designing deals with the process of turning of new chemical entity into a medication to be used safely and effectively by a patient. BIOAVAILABILITY It is defined as the rate and extent of absorption of unchanged drug from it’s dosage form . 3 Sagar Kishor Savale 4/27/2016

4. OBJECTIVE 2 To achieve a predictable therapeutic response To ensure product quality Chemical and physical stability Uniformity of dose Improve patient compliance 4 Sagar Kishor Savale 4/27/2016

5. Classification 1,2,3 5 Sagar Kishor Savale 4/27/2016

6. FACTORS AFFECTING DESIGN OF DOSAGE FORM 1 Physical & chemical properties of drug- Site of desired action- Rate & extent of absorption from various routes Effect of digestive juices & first pass effect Rapidity of the desired response- Accuracy of dosage Condition of the patient Nature and formulation of drug Route of administration. 6 Sagar Kishor Savale 4/27/2016

7. Administration of drug by ingestion. Intended for systemic effects resulting from drug absorption through the various epithelia and mucosa of the GIT. eg . Capsules, Tablets, Syrup, Emulsion ,Suspension Safe Convenient Economical No need for sterilization Advantages Oral Route 2 Drug action has slower onset son not suitable in case of emergency. Drug instability in GI fluid First-pass effect Irritation to gastric mucosa Disadvantages 7 Sagar Kishor Savale 4/27/2016

8. First-pass Effect 1 The first-pass effect is the term used for the hepatic metabolism of a pharmacological agent when it is absorbed from the gut and delivered to the liver via the portal circulation. The greater the first-pass effect, the less the agent will reach the systemic circulation when the agent is administered orally . Where ? Liver Gut wall Gut Lumen Result ? Low bioavailability. Short duration of action (t ½). 8 Sagar Kishor Savale 4/27/2016

9. SUBLINGUAL ROUTE Sublingual administration is where the dosage form is placed under the tongue rapidly absorbed by sublingual mucosa Advantages Rapid absorption Drug stability Avoid first-pass effect Disadvantages Inconvenient Small doses Unpleasant taste of drugs 9 Sagar Kishor Savale 4/27/2016

10. BUCCAL ROUTE Buccal administration is where the dosage form is placed between gums and inner lining of the cheek ( buccal pouch) absorbed by buccal mucosa ADVANTAGES Avoid first pass effect Rapid absorption Drug stability DISADVANTAGES Inconvenience advantages lost if swallowed Small dose limit 10 Sagar Kishor Savale 4/27/2016

11. RECTAL ROUTE Advantages Bypasses the portal circulation This route of administration has the additional advantage of preventing the destruction of the drug by intestinal enzymes or by low pH in the stomach. The rectal route is also useful if the drug induces vomiting when given orally, if the patient is already vomiting, or if the patient is unconscious. Disadvantages On the other hand, rectal absorption is often erratic and incomplete, and many drugs irritate the rectal mucosa. 11 Sagar Kishor Savale 4/27/2016

12. Parenteral administration is injection or infusion by means of a needle inserted into the body. Para, meaning outside enteron , meaning the intestine PARENTERAL 2,3 ADVANTAGE 100% bioavailability large quantities vomiting & diarrhea emergency situations avoided FPM gastric manipulation avoided DISADVANTAGES Irritation ,belonephobia Thrombophelebitis Less safe Technical assistance required Danger of infection Expensive less convenient and painful 12 Sagar Kishor Savale 4/27/2016

13. INTRAVENOUS Drug solution is injected directly in one of superficial vein either as bolus or infusion. I.M.ROUTE OF ADMINISTRATION 2 Drug is injected deep between the layers of one of large skeletal muscle because these are richly supplied with blood and less with nerves. Drug suspended in oily vehicle a preparation provide slower absorption characteristics . Provide depot preparation. 13 Sagar Kishor Savale 4/27/2016

14. The drug preparation is deposited in the loose subcutaneous tissue (under skin).It is richly supplied with nerve but less blood supply absorption of drugs is slower than im and iv. It is suitable for depot preparations. SUBCUTANEOUS INTRA ARTICULAR INJ. Inject the drug in Joints for the treatment of arthritis More skill is required Painful application Damage the cartilage 14 Sagar Kishor Savale 4/27/2016

15. INTRADERMAL Drug is given within skin layers (dermis) Painful Mainly used for testing sensitivity to drugs. Drugs which cannot cross BBB are administered through this route INTRA THECAL INJECTION 15 Sagar Kishor Savale 4/27/2016

16. INHALATION 1.Gaseous and volatile agents and aerosols 2.Rapid onset of action due to rapid access to circulation Particles size 0.5-1um absorb from alveolar sacs. a. Large surface area b.Thin membranes separates alveoli from circulation c. High blood flow ADVANTAGES The nasal cavity is well vascularised. Avoid FPM. Suitable ROA for drug which is degraded in the gut. DISADVANTAGES Irritation to respiratory track Most addictive route of administration. 16 Sagar Kishor Savale 4/27/2016

17. TRANSDERMAL 1,2 Transdermal drug delivery system are topically administered medicaments in the form of patches that deliver drugs for systemic effects at a predetermined and controlled rate. Highly lipid soluble drug can be applied over skin for slow and prolonged absorption Eg . nitroglycerine ointment . Administering medications to the skin Lotions, creams, ointments. Transdermal patches 17 Sagar Kishor Savale 4/27/2016

18. TOPICAL ROUTE 1 Topical administration is the application of a drug directly to the surface of the skin Includes administration of drugs to any mucous membrane Topical application is used when a local effect of the drug is desired. Dermal - rubbing in of oil or ointment (local action) eye – vagina nose – urethra ears – colon lungs 18 Sagar Kishor Savale 4/27/2016

19. EYE PREPARATION Application of drug into cornea of eye . REQUIRMENTS pH of preparation. Isotonicity Sterility Foreign material Viscosity 19 Sagar Kishor Savale 4/27/2016

20. ROUTE OF ADMINISTRATION: TIME UNTIL EFFECT 2 intravenous 30-60 sec inhalation 2-3 minutes sublingual 3-5 minutes intramuscular 10-20 minutes subcutaneous 15-30 minutes rectal 5-30 minutes ingestion 30-90 minutes T ransdermal (topical) variable (minutes to hours) 20 Sagar Kishor Savale 4/27/2016

21. Parenteral> Inhalation> Oral(Sublingual> Buccal )> Rectal> Topical BIOAVAILABILITY COMPARISION 1 21 Sagar Kishor Savale 4/27/2016

22. 22 Sagar Kishor Savale Pathway Of Drug 2 4/27/2016

23. 1) Brahmankar D.M. ,Sunil B.Jaiswal , Bioavailability and Bioequivalence, Biopharmaceutics and pharmacokinetics A treatise, 2 nd edition, Vallabh prakashan,2009,315-318, 499. 2) Aulton M. E. , “Pharmaceutics the science of dosage form design ’’2 nd edition, Churchill livingstone prakashan , 2002,1-6. 3)Leon lachman ,H. A. Lieberman, J. L. Kanig , Theory & Practice of Industrial Pharmacy,3 rd ed n V arghese publishing House,1976, Pg no. 223-226 REFERENCES : 23 Sagar Kishor Savale 4/27/2016

24. Queries??? 24 4/27/2016 Sagar Kishor Savale

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