This document discusses various routes of drug administration through mucosal membranes. It describes key considerations for drug delivery such as the structure of mucosal linings, drug properties like potency and solubility, and factors that influence drug absorption like permeability and metabolism. Specific routes covered include buccal, sublingual, ocular, rectal, and vaginal delivery. Advantages of these routes include avoidance of first-pass hepatic elimination and rapid onset with sublingual administration. Challenges and strategies to overcome barriers are also outlined.

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2.  Mucosal lining:
› Mucous ? Mucin ?
› Functions
 Epithelia 
› Thickness
› “wear and tear”stratified epithellia
› Keratinised-non keratinised epitelium

3.  Drug potency  consider the site of
administration
 Delivery form  release pattern
 Drug solubility  aqueous solubility – lipid
solubility  balance of hydrophilicity and
lipophilicity  partition and difusion
 Mucus- drug interaction
 Drug stability  consider the enzymatic
metabolism
 Degree of ionization  pKa  unionized
form absorbed

4.  Permeability
 Blood supply 
› High vasculature
› Blood flow

5. Oral administration vs oral cavity administration

6. Taken from Florence AT, Attwood D“Physicochemical Principles of Pharmacy”
- only for study purpose

7.  Buccal delivery
 Sublingual delivery
 Oropharyngeal delivery
 Periodontal delivery

8.  Avoidance of GIT hazardous
environment
 Avoidance of First Pass Hepatic
Elimination  there are no hepatic
portal veins  direct access to the
systemic circulation via internal jugular
vein
 Adequate vasculature and blood supply
 Relatively permeable
 Rapid onset  sublingual delivery
 Sustained release  buccal delivery

9.  Epithelial cell layer and mucous layer
thickness
 Mucous and saliva mobility

10.  Saliva movement and dilution
 Enzymatic barrier
 Thickness of mucosal layer
 Limited surface area
 Lipoidal barrier of buccal

11.  Mucoadhesive polymer
 Enzyme inhibitor
 Penetration enhancer
 Chemical modification

12.  Chewing formulation
 Fast release dosage form
 Mucoadhesive dosage form

14.  Eyelid
› Keep the tear film and lacrimal drainage
 Cornea
› Site of drug administration transcorneal absorption
› Epithelium-stroma-endothelium
 Conjunctiva
› Conjunctiva sac (the inferior one  “cul de sac”)(also) site of
drug instillation
› Drug absorption site
 Aqueous humor
 Iris-lens
› Light entry regulation
 Vitreous body and vitreous humor
› Keep the retina pressed against choroid
 Retina
› Visual acuity, nerves
› Configuration of photoreceptor cells
› Blood retinal barrier efflux system and tight junction on:
 Endothelium on retinal vessel
 Retinal Pigmented Epithellium (RPE) cells

15.  Ways to across the blood eye barrier
and cornea
› Blood-eye barrier
› Cornea
 Localisation the action at the eye
 Retention time while reducing the
frequency of instillation

16.  Safe and effective
 Sterile
 Certain criteria for certain dosage form:
› Pyrogen-free  parenteral administration
› Isotonic-Isohydris,
› free from particles solution (eyedrop-
injection)
› Free from large particles suspension-
ointment
› Free from foreign matters
 Advanced carrier  biodegradable

17.  Corneal penetration
 Noncorneal, productive ocular
absorption  conjuntival-scleral
absorption hydrophilic compounds
› Conjunctiva and sclera are more
permeable than cornea
› Could be non-productive if penetration
through conjunctival blood vessels occurs
 Noncorneal, non productive absorption,
› Conjuctival vessels  systemic
› Precorneal drainage (role of
hydrodynamic)80-90% drug removed

18.  Force out the matters from the eye and
perform nasolacrimal drainage
 Explain the effect of excessive
instillation:
› Bitter taste after instillation
› Systemic effect via GI absorption
 Suggest :
› the volume of eye drop administration (5-
10L/drop)
› The use of mucoadhesive carrierprolong
the residence time

19.  Solubility and partition coefficient
 Molecular weight
 State of ionisation and pH
 Protein binding
 Pigmentation and drug effect

20.  Proper placement of the dosage form
 Instillation volume
 The use of mucoadhesive polymer and
in situ gelling forming  viscosity
enhancement

21.  Mydriatics and Cycloplegics
 Miotics
 Anti-inflammation
 Anti bacterial-antifungal
 Anti-glaucoma
 Age related macular degeneration
 Dry eyes  artificial tears

22.  Most commonly used  benzalkonium
chloride (in a concentration of 0,01%);
 Role: microbial growth controller, it can
also be used as penetration enhancer
 Limitation:
› If the concentration exceeded, may cause
irritation/corneal damage).
› incompatible for salt form active
ingredientanionic-cationic interaction)
 Other organic mercurials careful
with the side effect of mercury!

23.  Intravitreal administration
 Subconjunctival administration
 Periocular administration
› Sub Tenon’s capsule administration
› Retrobulbar injection

25.  Local therapy, example…
 Systemic therapy, especially in condition:
› Unable for oral administration
› Unconscious
› Unacceptable taste
› Unstable against GI hazardous environment
 Advantages :
› Non invasive; can be self administered
› For systemic :
 High vasculature
 Permeability
anatomy

26.  Suppositoria
 Rectal gel:
 Enema

27. Microlax ?
www.drugs.com

28.  Bases:
› Fatty base (melted) cocoa butter; adeps
solidus; witepsol
› Water soluble base (dissolved)  osmotic
effect hygroscopic
› Glycero-gelatine base  hygroscopic
 Consideration:
› Melting point
› Solidification rate
› API-excipient affinity/interaction

29.  Local therapy, mostly related to
antibiotics-antifungi
 Points for systemic delivery:
› Blood supply
› Permeability
› Hepatic FPE avoidance
› Less protease

30.  Ethic issues
 Erratic absorption due to epithellium
thickness variation as the consequences
of menstrual cycles
 Mucus as physical barriers