This ppt covers advantages, disadvantages, anatomy of buccal mucosa , muco adhesion theories, mechanism of drug permeation, etc

1.  Siddu K M
 M Pharm 1st Year
 Department of pharmaceutics
 Al Ameen College of Pharmacy, Bangalore
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1. INTRODUCTION
2. ADVANTAGES
3. DISADVANTAGES
4. ANATOMY OF BUCCAL MUCOSA
5. MUCO ADHESION
6. THEORIES OF ADHESION
7. MECHANISM OF DRUG PERMEATION
8. EXAMPLE FOR BUCCAL TABLET
9. REFERENCES

3.  It is the administration of drug via the buccal mucosa
(the lining of the cheek) to the systemic circulation.
 Buccal cavity mucosa was the most convenient and also
easily approachable site for purpose of delivering the
therapeutic agent for both local as well as systemic
delivery.
 The buccal mucosa lines the inner cheek and buccal
formulation are placed in mouth between the upper
gums and cheek to treat local and systemic conditions.
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5.  Drug is easily administered and extinction of therapy in emergency can
be facilitated.
 Drug release for prolonged period of time.
 In unconscious and trauma patient’s drug can be administered.
 Drugs bypass first pass metabolism so increases bioavailability.
 Some drugs that are unstable in acidic environment of stomach can be
administered by buccal delivery.
 Rapid onset of action.
 Good patient compliance with respect to parenteral.
 Large surface area with respect to sub-lingual mucosa.
 Presence of the saliva helps in dissolution of drug. 5

6.  Drugs which are unstable at buccal pH cannot be administered.
 Drugs which have a bitter taste or unpleasant taste or an obnoxious
odour or irritate the mucosa cannot be administered by this route.
 Drug required with small dose can only be administered.
 Those drugs which are absorbed by passive diffusion can only be
administered by this route.
 Eating and drinking may become restricted.
 Not for children
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 Buccal mucosa is divided into three main
categories
A. Stratified squamous epithelium
B. Basement membrane
C. Lamina propria
1. stratum basale
2. Stratum spinosum
3. Stratum granulosam
4. Sratum corneum

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 Stratified squamous epithelium have a thickness of 500-800µm, which
may be keratinized or non keratinized.
 Keratinized epithelium is mechanically tough and chemically resistant.
 It is found in areas of oral cavity i.e. mucosa of the gingiva and dorsal
surface of tongue.
 Non keratinized epithelium is relatively flexible and is found in the
floor of the mouth, inner lips and inner cheeks.
 Thus the regions of the oral cavity pertinent to drug delivery (buccal
and sublingual) have a non keratinized epithelium.

9.  ‘Mucoadhesive’ is defined as a substance that is capable of interacting
with biological material and being retained on them or holding them
together for extended period of time.
Theories of Mucoadhesion or Bioadhesion
1. Wetting Theory
2. Diffusion Theory
3. Electronic Theory
4. Fracture Theory
5. Adsorption Theory
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10. 1. WETTING THEORY
 Wetting is the ability of a liquid to maintain contact with a solid
surface, resulting from intermolecular interactions when the two are
brought together.
 The degree of wetting is determined by force balance between
adhesive and cohesive forces.
 This wetting theory applies to liquid systems which adhere to the
mucosal surface in order to spread over it.
 This adhesion is depending on Contact angle i.e., lower the contact
angle more will be the affinity.
 The work of adhesion can be given by
Wa= 𝜸A + 𝜸B - 𝜸AB
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12. 2. DIFFUSION THEORY
 This theory describes the interpenetration of both polymer chains
and mucin chains to a sufficient depth to create a semi permanent
adhesive bond.
 Here, polymer first brought into intimate contact with the mucous
and over a time, the concentration gradient across the interface
cause the diffusion of the chains of polymer into the mucous layer.
 The adhesion force increases with increase in degree of penetration
of the polymer chain.
 In order for the diffusion to occur, the components involved i.e.,
both bio adhesive and mucous membrane have similar chemical
structures.
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14. 3. ELECTRONIC THEORY
 According to this theory, electronic transfer occurs upon contact of
an adhesive polymer and the mucus glycoprotein network because
of differences in their electronic charge.
 This result in the formulation of an electronic double layer at the
interface.
 Adhesion occurs due to attractive forces across the double layer.
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15. 4. ADSORPTION THEORY
 The polymer gets adsorbed on the mucous membrane because of
the surface forces acting between the chemical moieties present
on both the surface.
 Two types of chemical interactions occur
1. primary bonds(covalent, ionic & metallic)
• Permanent bond due to high strength.
• Not desirable for muco adhesion.
2. Secondary bonds(van der waal’s forces, hydrogen bonds)
 Semi permanent bonds and less energy to break.
 Most desirable for muco adhesion.
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16. 5. FRACTURE THEORY
 According to Fracture theory of adhesion, it is related to separation
of two surfaces after adhesion.
 It analyzes the force required to separate two surfaces after adhesion
is established.
 This assumes that the failure of adhesive bonds occur at the interface.
 Failure normally occurs at the weakest component, which is typically a
cohesive failure within one of the adhering surfaces.
 The Maximum Strength of detachment (Sm) can be determined by
dividing the maximum force of detachment (Fm) by the total surface
area (Ao).
Sm = Fm ÷ Ao
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18. 1. Passive diffusion
a) Transcellular or intracellular route
b) Paracellular or intercellular route
2. Carrier mediated transport
a) Active diffusion
b) Facilitated diffusion
3. Endocytosis
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19.  it is transfer of drug molecules across concentration gradient from a
higher concentration(buccal drug dosage form) to a lower
concentration(mucous membrane).
 Transcellular :
• Route of lipophilic drugs.
• Lipid drugs passes through lipid rich mucous membrane.
 Para cellular :
• Primary route for hydrophilic drugs
• Hydrophillic drugs passes through intercellular spaces.
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20.  Movement which occurs across membranes, such as the blood-
brain barrier and the mucosal membrane with the help of “carrier”.
 This mechanism is a rapidly reversible reaction between the drug
being transported and the components of the membrane.
 Active transport :
 Transport of drug molecules across the mucous membrane from region of lower
concentration to a region of higher concentration by using trans membrane proteins
using ATP.
 Facilitated diffusion :
 Transport of drug molecules across mucous membrane from region of higher
concentration to a region of lower concentration by means of trans membrane
proteins.
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21.  Endocytosis is the process of actively transporting drug molecules into
the cell by engulfing it with its membrane.
 Phagocytosis :
 Intake of solid drug molecules into the cell by forming vesicles.
 Pinocytosis :
 Intake of liquid drug molecules into the cell by forming vesicles.
 Receptor mediated endocytosis :
 Intake of drug molecules into the cell with the help of receptors present on the
membrane and forming vesicles.
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Ingredients For each Tablet
(mg)
Valsartan Active drug 15
Carbopol 934 Bioadhesive polymer 20
HPMC K4M Bioadhesive polymer 60
Mannitol diluent 13
Magnesium Stearate lubricant 1
Talc glidant 1
Ethyl Cellulose Backing layer 40

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25. 1. Journal of Pharmaceutical Sciences and Research/Overview on Buccal
Drug Delivery Systems.
2. International Journal of Research in Ayurveda & Pharmacy/Theories
and factors affecting muco adhesive drug delivery systems.
3. Wikipedia/Mechanisms of drug permeation. And oral mucosa
4. International journal of Drug Development and Research/Formulation
and evaluation of Mucoadhesive Buccal tablets of valsartan
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