Oro-mucosal Administration Flashcards
What can mucosal delivery include?
- oral
- nasal
- intestinal
- vaginal
- pulmonary
- rectal
- ocular
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Label the image
1 tongue
2 soft palate
3 hard palate
4 gums and teeth
5 lips
6 uvula
What are the three types of stratified squamous epithelia in the mouth and where are they found?
Masticatory mucosa
- keratinised
- sustains mechanics of chewing
- found in hard palate, gums
Lining mucosa
- non-keratinised
- less of a barrier to drug absorption
- found in lips, cheeks, sublingual area, soft palate
Specialised mucosa
- taste buds on tongue
What does saliva contain?
- water
- electrolytes
- glycoproteins
- enzymes (amylases)
- natural antimicrobials
What are the 3 main glands producing saliva and where are they located?
- sublingual
- parotid (close to ears)
- submandibular (lower jaw)
What is the pH of the oral cavity and what enzymes are present?
- 6.2-7.4
- amylases
What are the roles of the oral cavity?
- mastication
- taste
- deglutition
What conditions are treated with oro-buccal administration for local effect? What are the considerations?
- dry mouth
- infection
- irritation
- pain
- ulceration
Consider:
- contact with site of action
- residence time
- organoleptic properties
- sugar content
- acidity
What are the characterisitics of lozenges and considerations?
- easy to administer
- manufacture by compression or moulding
- pH
- sugar content
- sugar free alternatives
- organolpetic properties
Describe the properties of hard lozenges.
- similar to hard candy
- low moisture content (0.5-1.5%)
- potentially high sugar content (55-65% sucrose)
- prepared at high temp
Describe the properties of soft lozenges.
- bases
- PEG 1-1.45 Da
- fatty base
- gelatin
- glycerin
- sugar/acacia (50 degrees)
- silica gel (suspending agent)
- chewed or left to dissolve
Describe the properties of chewable lozenges.
- Composition
- glycerin and gelatin
- API
- colour
- flavour
- caution in paediatric use - may be percieved as candy
How do you treat mouth ulcers?
Can heal on their own but to help:
- mouthwash (saling/antiseptic)
- gels
- sprays
- soft lozenges
What is xerostomia and what can it be a result from?
Dry mouth
- ADR to
- anticholingernic drugs
- diuretics
- chemo or radiotherapy
- medical condition eg
- sjogren syndrome
- nerve damage
- dehydration
- others
- smoking
- breathing through mouth
- stress
What does dry mouth increase the risk of?
dental and peridontal conditions
How can xerostomia be treated?
adressing the underlying cause or using measures that increase salivation such as
- lozenges
- sprays
- gels
- soft lozenges
How can you treat infection?
- hydrogen peroxide
- chlorhexidine
- antifungals
- nystatin suspension
- miconazole gel
How do you treat herpes labialis and what is it?
cold sore
treat with topical treatment unless immunocompromised
- creams
- antiviral
- disinfectants
- patches
- non medicated helps with wound healing and provides a barrier effect
Where can products for systemic effect be absorbed from?
- sublingual compartment
- bucal mucosa
- labial mucosa (lining of lips)
What are barriers to absorption for products for systemic effect?
- physiological barriers
- physiochemical barries
- formulation barriers
What are advantages of products for systemic effect?
- quick onset of action (lack of FPM, direct absorption into bloodstream)
- ease of administration
- patient adherences (possiblility for sustained release)
- neutral envrionment in oral cavity (lower metabolic activity, close to neutral pH)
What are disadvantages of products for systemic effect?
- unsuitable for irritant drugs (damage to mouth mucosae)
- limit to dose administered
- require adequate use by patient (possible restrictions on timing of eating/drinking)
- difficulties in dose splitting
- impact of saliva (drug wash out into saliva)
Summarise the surface area, pH, fluid volume and enzyme activity in different sections of the GIT.
- Small intestine has highest surface area
- Stomach is most acidic pH 1-3
- Fluic volume lowest in buccal but quick turnover of saliva
- Largest enzyme activity in stomach and small intestine, least in rectum
Fill out the gaps.
What are the drug properties to consider for buccal delivery?
- ionisation (pH 6.2-7.4)
- solubility/permeability
- absorption
- dissolution rate
- MW
What molecules are suitable for passing through thr paracellular pathway to blood?
Small, hydrophilic molecules
What increases permeability?
permeation enhancers
How does a oro-bucal solution work?
it must stay in contact with the lining mucosa (eg cheek) and is administered using the applicator provided
eg midazolam
What are the benefits and limitations of medicated chewing gum?
- oral care
- no water required
- stress relief
- organoleptic properties
- variable release
- production costs
- similar issues as non-medicated gum
Describe oro dispersible formulations
- can be films or tablets
- quick dissolution, no water required
- some sre not meant for oromucosal absorption, patient may be expected to swallow drug after tablet or film has dissolved
What are advantages of orodisperible formulations?
- convenience
- immediate release
- ease of administration
- can be suitable for patient with difficulty swallowing
- less obtrusive than bucal tablets
- improved bioavailability
- provided it stays in contact with site
What are disadvantages of orodisperible formulations?
- difficult to split dose
- very hygroscopic
- organolpetic properties
- fraction of drug may be swallowed
Describe compressed lozenges.
- produced through compression of a powder blend
- high mechanical strength
- low porosity
- formulated using dextrates as diluent and without disintegrant
- should not be chewed or swallowed whole
- high inter and intra individual variability
How does cationic material work?
through electrostatic interactions with the negatively charged mucus layer
How does anionic and neutral material work?
through hydrophobic and/or hydrogen bond formation
What are the properties of mucoadhesive material?
- biocompatible
- non-toxic
- non-irritant
- form strong bonds
- produce quick adhesion
- have no imcompatabilities
- have good stability
- be cost effective
What is non specific and specific adhesion to the mucosal surface?
Non-specific
- electrostatic
- hydrophobic
- hydrogen bond
Specific
- carbohydrates
- proteins
What are advantages of mucoadhesive tablets?
- slow dissolution
- improved contact with site of absorption
- increased residence time
What are disadvantages of mucoadhesive tablets?
- discomfort
- can be irritant
- can detach from mucosa
- risk if it adheres to different mucosal surface
What are advantages of sublingual administration?
- rapid onset of action
- ease of administration
- extensive drug absorption
- thin lining mucosa
- can be used in emergencies
- fast dissolution of dosage form
- no need for water intake
What are disadvantages of sublingual administration?
- can interfer with drinking/eating
- not used for sustained drug release
- may be hard to use in unconcious patients
- smoking may reduce absorption
- size limit to ensure patient comfort
