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Journey through GI > Mucoadhesion > Flashcards

Flashcards in Mucoadhesion Deck (11)
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1
Q

what is mucoadhesion

A

defined as interfacial force interactions between synthetic or natural polymeric materials serving as a dosage form and a mucus layer that covers a mucosal tissue

2
Q

describe the structure of mucosal membranes

A

layer of soluble mucins

layer of cell bound mucins

epithelial cells

3
Q

what functions does the mucosal membranes have

A

protection of epithelial cells from physical and chemical destruction

lubrication

wetting

modulation of water content in the underlying tissue

4
Q

what are some characteristics of mucosal surfaces

A

dynamic surface that is reformed constatnly through the secretion of mucins

relatively short life time

efficient semi permeable barrier system

5
Q

what are the clearance times of mucosal surfaces in

ocular

respiratory tract

gastro intestinal tract

A

5.0 - 7.7 min

20 min

4 - 6 hours

6
Q

what types of solid formulation of mucoadhesives exist

A

tablets
inserts
lozenges
films

7
Q

what type of semi solid mucoadhesive formulation exist

A

gel + paste
viscous liquid
gel forming liquids

8
Q

what are the advantages of a mucoadhesive delivery

A

increased dosage form residence time

improved drug bioavailability

reduced administration frequency

simplified administration / termination of a therapy

non invasive

possibility of targeting particular body sites and tissues

avoidance of the metabolism associated with the passage through the GI tract

9
Q

what are some specific features of mucoadhesive polymers

A

hydrophilic or water soluble polymers

negatively or positively charged groups (polyelectrolytes)

if both positively and negatively charged groups mucoadhesion is poor

strong hydrogen bonding groups

10
Q

what factors affect mucoadhesion

A
molecular weight of polymers 
concentration of mucoadhesive
chain flexibility
cross linking density of polymers
pH
Presence of non muco adhesive co-excipients
11
Q

what are second generation mucoadhesive materials

A

materials whose mucoadhesive properties were enhanced with chemical modification

this enhancement is achieved through the ability o materials to form covalent bonds with molecules present on mucosal surfaces