This document discusses buccal drug delivery systems (BDDS), which deliver drugs through the buccal mucosa in the mouth. It defines BDDS and describes the three categories of oral mucosal drug delivery. The document outlines the advantages and disadvantages of BDDS, examines the anatomy and physiology of the oral mucosa, and explores formulation components like polymers and permeation enhancers. Finally, it discusses various buccal dosage forms like tablets, patches and films as well as evaluation methods.

1. A seminar on
buccal drug delivery system
Under the guidence of DR L.srinivas
prepared by Y.d.n.satish roll no 121825101004
mpharmacy 3 semester
pharmaceutics

2. What is buccal drug delivery system???
Delivery of drug through buccal mucosa of oral
cavity is called BDDS. Buccal mucosa lines the
inner region of cheeks.
In biological term , the product is placed between
upper gingiva and cheek to treat local and
systemic conditions.

3. ● Drug delivery inside oral mucosa can be divided
into the following three categories :
● Local drug delivery :delivery of the drug locally
in the oral cavity
● Sublingual drug delivery :delivery of drug into
the systemic circulation through the mucosal
membrane lining the base of the mouth below the
tongue
● Buccal drug delivery :drug administered through
the membrane lining the cheeks

4. region average epithelium thickness
um
Skin 100-120
Hard palate 250
Attached gingival 200
Buccal mucosa 500-600
Floor of mouth 100-200

5. Advantages
● Provides ease of administration
● Allows easy removal of dosage form in case of
toxicity
● Permits localization of the drug for a prolonged
period of time
● Allows administration to coma stage patients
● Provides flexibility in physical state , shape, size ,
and surface
● Allows rapid onset of action

6. ● Offers greater permeability than the skin
● Avoids first – pass metabolism thereby reducing
dose and dose- dependent side effects
● Choice being made unidirectional to ensure only
buccal absorption
● Provides maximum absorption due to direct
contact with the absorbing membrane
● Permits administration of drugs that are unstable
in acidic atmosphere of stomach or are damaged
by the enzymatic or alkaline surroundings of the
intestine

7. Disadvantages
● Drug with bitter taste or irritant to mucosa or
having noxious smell
● The drugs with small dose requirements can only
be administered
● Drugs that are unstable at buccal pH cannot be
administered
● Only the drugs that follow passive diffusion for
absorption can be administered through this route
● Eating and drinking may become restricted
● There is an involuntary removal of dosage form
● There is always a possibility that the patient may
swallow the dosage form

8. ● Continuous secretion of the saliva leads to
subsequent dilution of drug
● There is a relatively small surface area and low
permeability of buccal mucosa compared to other
routes of administration
● Swallowing of saliva may lead to loss of
dissolved drug
● Drugs that irritate the mucosa or have bitter taste
or an intolerable odor cannot be administered

9. Anatomy and physiology of oral
mucosa
● The oral cavity is lined by thick dense and
multilayered mucous membrane passes through
net of capillaries and arteries and reaches the
systemic circulation
● There are mainly three functional zones of oral
mucosa :
Masticatory mucosa
Mucous secreting region
Specialized mucosa

10. ● The drugs with small dose requirements can only
be administered
● Drugs that are unstable at buccal pH cannot be
administered
● Only the drugs that follow passive diffusion for
absorption can be administered through this route
● Eating and drinking may become restricted
● There is an involuntary removal of dosage form
● There is always a possibility that the patient may
swallow the dosage form
● Continuous secretion of the saliva leads to
subsequent dilution of drug
● There is a relatively small surface area and low
permeability of buccal mucosa compared to other
routes of administration

12. Buccal environment
● It has four parts and is 500-800µm thick
● Epithelium : 40-50 cell thick and is major barrier
for lipophilic drug . It has initially square shaped
cells which further grows in the elliptical cells
which are permeable for hydrophilic drugs . It
may be keratinized or non keratinized
● Mostly non keratinized epithelium is permeable
to drug very easily due to absence of acyl
ceramides and only small amounts of neutral but
polar lipids. Hence more permeable to
formulation
● Lamina propria : barrier for hydrophilic drug
● Hence highly hydrophilic and highly lipophilic
drug are not suitable for BDDS

13. Mechanism of adhesion
● The term bioadhesion is commonly defined as
adhesion between two materials where at least
one of the material is of biological origin
● When adhesion is restricted to mucous layer
lining of the mucosal surface then it is known as
the mucoadhesion .
● Generally such adhesion occurs in four different
steps
● Wetting and swelling
● Interpenetration of polymer chains in mucin
chains
● Formation of chemical bonds between enlarged
chains

14. ● 1. wetting and swelling of polymer to permit
intimate contact with biological tissue
● 2. inter- penetration of bioadhesive polymer
chains and entanglement of polymer and mucin
chains.
● 3. formation of chemical bonds between enlarged
chains
● Chemical bonds may be primary or secondary

15. Theories of adhesion
● Adsorption theory : polymer or groups from
covalent bonds which will bind very strongly
● Wetting theory : polymer with positive spreading
coefficient will have good binding
● Diffusion theory : permeability is good in mucin
due to chain flexibility
● Fracture theory: Irregular surface of polymer and
mucin give good physical entanglement
● Electronic theory: electric bilayer between
polymer and mucin is responsible

16. Formulation of BDDs
Solid dosage form
● Tablets
● Patches films
● Wafers
● Lozenges
● Powders
Semi solid dosage forms
● Gels
● Ointments
Liquid dosage forms
● spray

17. Basic formulation components
● Preferred drug candidates are :
● Mucoadhesive polymer
● Permeation enhancer
● Diluents
● plasticizer

18. Selection of drug for BDDS
● Molecular weight should be less than 1000 da
● It should be having both nature (hydro-lipophilic
type)
● Should be potent
● Non irritant to mucosa
● Drugs that degrades in GIT

19. Mucoadhesive polymers
● These are the main component for adhesion
● They attract water from the biological
surrounding , get swells and adhere to the
membrane
● Normally they should be having hydrophilicity ,
numerous H- bonding groups , flexibility ,
interpenetration with mucus and tissues

20. Ideal features
● Non toxic , non irritant and pure
● Good spreadability , wetting , swelling , solubility
and biodegradable if possible
● Adhesion should be quick and with sufficient
mechanical strength
● Should have peeel , tesile , shear strength
● Should easily incorporate drug in formulation and
it should not be obstacle in drug release
● Cost effective

21. Permeation enhancers
● Permeation is very limiting factor in BDDS
● Substances that facilitates permeation through
buccal mucosa are called penetration enhancers
● Epithelium and lamina propria are very effective
barrier to absorption
● they should be used with very care and in
optimum concentration (<1%) above this
concentration toxicity due to membrane damage
may occur and histopathological study should be
done .

22. Important formulation
● Tablets
● Is small, falt generally oval shape with5-8 mm
diameter
● It is directly placed onto mucosal surface and
adheres to it
● We can get
● Unidirectional release
● Multidirectional release
● Generally for unidirectional release , a backing
membrane is applied , which is impermeable to
liquid , to one side so that no drug release is
observed from that side and non –coated surface
adheres to the buccal mucosa . Ethyl cellulose is
used as backing membrane

23. Different marketed buccal tablets
● Fentanyl buccal tab
● Testosterone patented product

24. Buccal patches / films
● They are long , flat, thin thickness , transparent
with high surface area
● They can be prepared by two methods :
● Solvent casting method
● Direct drilling method

25. Solvent casting method
● Here drug and all excipients are weighed and
dispersed in the suitable organic solvent and
coated on the release liner
● The organic solvent is allowed to evaporate and
after evaporation the thin layer of the backing
material is laminated on to the sheet of coated
release liner to form laminate
● After that the whole patch is ready to cut into
required size

26. Direct milling method
● Here drug and excipients are mixed mechanically
by milling and kneading
● After mixing the resultant material is rolled on the
release liner till desired thickness is achieved
● Finally as the previous method , backing material
is laminated
● Though there is no difference in patch
performance manufactured by either of the
method but with the solvent method there are
chance of residual solvent
● Hence this solvent free method is highly used

27. What does backing layer does
● Backing layer control the direction of drug release
● Also prevent drug losses
● Minimize deformation during handling and
transportation
● Reduces the disintegration of device during the
application
● examples
● Niroglycerin patches
● Fentanyl patches

28. Recent innovations
● Gel Forming liquids
● This type of a formulation is liquid upon
instillation and undergoes a phase transition to
form a viscoelastic gel in response to stimulate
such as temperature , ionic strength or pH
● Carbomers become more viscous upon increased
pH
● Gellan gum and alginate both form gel in
response to increased ionic strength
● Poloxamers and smart hydrogel gel at at
approximately body temperature

29. ● Slowly disintegrating buccal mucoadhesive plain
tablet
● Prepared by incorporating large amount of HPC
● Limitations :
● Softens on extended period and
● Lose its shape which hinders the control of
disintegration over long time periods

30. Design of buccal dosage forms
● Matrix type :
● The buccal patch designed in a matrix
configuration contains drug , adhesive and
additives mixed together .
● Bi- directional patches release drug in both the
mucosa and the mouth
● Drug + mucoadhesive matrix

31. ● Reservoir type : the buccal patch designed in a
reservoir system contains a cavity for the drug
and additives separate from the adhesive
● Impermeable backing is applied to control the
direction of drug delivery; to reduce patch
deformation and disintegration while in the
mouth; and to prevent drug loss

32. Drug delivery pathways
● Two possible routes of drug absorption through
oral mucosa
● Transcellular route : preferred by lipophilic drugs
● Paracellular route : preferred by hydrophobic
drugs

33. Uses of buccal delivery
● The oral cavity can be used for local and systemic
therapy
● Examples of local therapy would be the treatment
of oral infections , dental caries , mouth ulcers ,
stomatitis , gingivitis
● The buccal route is of particular interest with
regard to the systemic delivery of small molecules
that are subjected to first-pass metabolism

34. Buccal mucoadhesive dosage forms
● Three types based on geometry :
● Type 1
● Single layer device with multi directional release
● Significant drug loss due to swallowing
● Type 2
● Impermeable backing layer is superimposed
● Preventing drug loss into the oral cavity
● Type 3
● Unidirectional release device , drug loss is
minimal
● Achieved by coating every face except contact
face

35. Evaluation of buccal tablets
● Parameters of evaluation:
● Determination of residence time
● Permeation studies
● Swelling studies
● Release rate studies
● Toxicity and irritation study
● Bioadhesion measurement
● Folding endurance content uniformity
● Surface pH