Greetings! Good Day to All.. This presentation is all about ABSORPTION OF DRUGS - NON PER ORAL - EXTRA VASCULAR ROUTES which covers about the various route of administration which are administered other than oral route like 1. Buccal / Sublingual 2. Rectal 3. Topical & Transdermal 4. Parenteral 5. Pulmonary & Intra nasal 6. Intra ocular & 7. Vaginal Administration Your suggestion and comments are welcome for further improvement in my presentations. Thank you all for your valuable time. Disclaimer Note: Some contents in the presentation were taken from online sources which is purely used for education purpose and for any personal financial or commercial aspects. I thank all the source providers in online for your efforts and support in sharing of knowledge.

2. Dr S Ramkanth, M. Pharm., Ph.D. Professor & Head, Department
Route of Administration – By pass the First
Pass metabolism
2

3. Dr S Ramkanth, M. Pharm., Ph.D. Professor & Head, Department
Buccal / Sublingual Administration
3
The barrier to drug absorption by this routes is
the epithelium of oral mucosa.
 Passive diffusion is the major mechanism for
absorption of most drugs; nutrients may be
absorbed by career-mediated processes.
 The buccal and sublingual route appear ideal
for lipid soluble drugs.
 Examples-
 Anti anginals- nitrites and nitrates
 Anti hypertensives- nifedipine
 Analgesics- morphine; bronchodilators-

4. Dr S Ramkanth, M. Pharm., Ph.D. Professor & Head, Department
Buccal / Sublingual Administration
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Factors to be considered in oral mucosal delivery
are
 Lipophilicity of drug
 Salivary Secretion
 pH of saliva
 Binding to oral mucosa
 Storage compartment
 Thickness of the epithelium
 Mucosal Surface Area
 Taste of the medicaments

5. Dr S Ramkanth, M. Pharm., Ph.D. Professor & Head, Department
Rectal Administration
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 Drugs may be administered as solutions (microenemas) or
suppositories.
 Absorption from solution is better.eg - lincomycin.
 In this form, a drug is mixed with a waxy substance that
dissolves or liquefies after it is inserted into the rectum.
 The drug is absorbed from the rectum and anal canal by
passive diffusion of the unionized drug.

6. Dr S Ramkanth, M. Pharm., Ph.D. Professor & Head, Department
Topical Administration
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 It is the largest organ of the body with the body weight approximately 2kg
and 2 sq m in area and received about 1/3 0f total circulation.
 Majority of drug applied topically are meant for local and systemic effects.
 Dosage forms here are cream, ointments, lotion, gels, transdermal patches
and discs.
 When topically applied drug are meant exert their effects systemically , the
mode of administration is called as Percutaneous or Transdermal delivery.
 Diffusion through the multiple lipid bilayers of dead, hydrophilic keratinized
and horny cells of stratum corneum is the rate limiting step.
 Topical drug application
1) systemic delivery – Clonidine, scopolamine, nicotine, fentanyl
2) Local delivery – Antimiotics , Antiinflammatories , Anaesthetics

7. Dr S Ramkanth, M. Pharm., Ph.D. Professor & Head, Department
Topical Administration
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There are three pathways postulated for the diffusion of solutes through the skin:
Transcellular (passive diffusion)-
 cross keratinized cells.
 Accessible to non-polar molecules.
 hydrophilic drug show penetration through this layer.
Intercellular (paracellular)-
 Across the lipid matrix.
 Accessible to non-polar molecules
 Lipophilic drugs show penetration through this layer.
Transappendageal–
 Accessible to polar molecules
 Across hair follicles, sweat gland, sebaceous glands

8. Dr S Ramkanth, M. Pharm., Ph.D. Professor & Head, Department
Transdermal Route
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 Transdermal Drug Delivery System (TDDS) are defined as self
contained, discrete dosage forms which are also known as
“patches” when patches are applied to the intact skin, deliver
the drug through the skin at a controlled rate to the systemic
circulation.

9. Dr S Ramkanth, M. Pharm., Ph.D. Professor & Head, Department
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Factors influencing percutaneous absorption of drugs
are
 Thickness of stratum corneum
 Presence of Hair Follicles
 Trauma
 Hydration of skin
 Environment humidity and temperature
Topical Administration
 Age
 Grooming
 Exposure to chemicals
 Vehicle or base
 Permeation enhancers
 Chronic use of certain drugs

10. Dr S Ramkanth, M. Pharm., Ph.D. Professor & Head, Department
Parenteral Route
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Direct delivery of drug in to systemic circulation without intestinal
mucosa
 Intramuscular (I.M.) (into skeletal muscle)
 Subcutaneous (S.C.) (into subcutaneous tissue)
 Intravenous (I.V.) (into veins)
 Intradermal (I.D.) (into skin)
 Intra-arterial (I.A.) (into arteries)
 Intra-thecal (I.T.) (cerebrospinal fluid)
 Intra-peritoneal (I.P.) (peritoneal cavity)
 Intra - articular (Synovial fluids)

11. Dr S Ramkanth, M. Pharm., Ph.D. Professor & Head, Department
Parenteral Route - Intramuscular Administration
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 Absorption of drug from i.m site is
relatively rapid but much slower in
comparision to I.V injection.
 Absorption of lipophilic drugs occurs by
passive diffusion into blood circulation and
lymphatic system.
 Hydrophilic and unionic drugs are absorbed
into blood circulation via the capillary

12. Dr S Ramkanth, M. Pharm., Ph.D. Professor & Head, Department
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Factors determining the rae of drug absorption from
I.M sites are
 Vascularity of the injection site
 Lipid solubility and inonization of drug
 Molecular size of the drug
 Volume of injection and drug concetraion
 pH, composition and viscosity of injection vehicle
Parenteral Route - Intramuscular Administration

13. Dr S Ramkanth, M. Pharm., Ph.D. Professor & Head, Department
Parenteral Route - Subcutaneous administration
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 Absorption of drug from subcutaneous site
slower than the intramuscular site.
 Administration of drug that degrade when taken
orally eg- insulin, sod heparin.
 Absorption occur by passive diffusion
 Rate of absorption depends upon blood flow and
injection volume
 It is used only when drug does not cause
irritation, otherwise severe pain, necrosis or
tissue damage may occur.
 Rate of absorption from this site can increase by-
1) Enhancing blood flow to the injection site- By

14. Dr S Ramkanth, M. Pharm., Ph.D. Professor & Head, Department
Pulmonary Administration
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 The drug are generally administered by
inhalation either as gases or aerosol which are
rapidly absorption just like exchange of gases
between the blood and inspired air.
 Absorption of hydrophilic drugs occur by diffusion
through aqueous membrane pores.
 Lipophilic drugs are absorbed by passive
diffusion.

15. Dr S Ramkanth, M. Pharm., Ph.D. Professor & Head, Department
Pulmonary Administration
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 Drug delivery to lungs is dependent upon
the particle size of the aerosolised
droplets-
 Particles > 10μ impact on the mouth,
throat or upper respiratory tract mucosa
and do not reach the pulmonary tree.
 Very small particles- 0.6 μ from which
drug absorption is rapid.

16. Dr S Ramkanth, M. Pharm., Ph.D. Professor & Head, Department
Intranasal Administration
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 Drug absorption by this route is as rapid as
parenteral administered because of its high
permeability and rich vasculature.
 Eg: Drugs used to treat local symptoms like nasal
congestion, rhinitis, etc.
 Popular for administration of peptides and protein
drugs.
 Mechanisms for the drug delivery from nose to the
brain:

17. Dr S Ramkanth, M. Pharm., Ph.D. Professor & Head, Department
Intranasal Administration
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 Absorption depend upon drug lipophilicity and
molecular weight.
 Rapid absorption by diffusion is observed up to
400 - 1000 Da.
 Lipophilic drugs shows rapid absorption by
diffusion and Hydrophilic drugs are absorbed by
pore transport.
 Use of permeation enhancer shows reasonable
bioavailability for durgs of 6000 Da

18. Dr S Ramkanth, M. Pharm., Ph.D. Professor & Head, Department
Intraocular administration
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 Sterile aqueous solutions of drugs are
administered in the conjunctival cul-de-sac.
 The barrier to intraocular penetration of
drug is the cornea which posses both
hydrophilic and lipophilic characteristics. It
possess passive diffusion.
 Various factors to be considered are
 pH of Lacrimal fluid

19. Dr S Ramkanth, M. Pharm., Ph.D. Professor & Head, Department
Vaginal administration
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 Drugs meant for intravaginal action are
generally intended to act locally in the
treatment of bacterial or fungal
infections or prevent conception.
 The drugs are absorbed by passive
diffusion into the systemic circulation.
 Factors influence the absorption are -
pH of lumen fluid (4-5), Vaginal

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