Mucoadhesion

Question 1

what is mucoadhesion

Answer 1

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

Question 2

describe the structure of mucosal membranes

Answer 2

layer of soluble mucins

layer of cell bound mucins

epithelial cells

Question 3

what functions does the mucosal membranes have

Answer 3

protection of epithelial cells from physical and chemical destruction

lubrication

wetting

modulation of water content in the underlying tissue

Question 4

what are some characteristics of mucosal surfaces

Answer 4

dynamic surface that is reformed constatnly through the secretion of mucins

relatively short life time

efficient semi permeable barrier system

Question 5

what are the clearance times of mucosal surfaces in

ocular

respiratory tract

gastro intestinal tract

Answer 5

5.0 - 7.7 min

20 min

4 - 6 hours

Question 6

what types of solid formulation of mucoadhesives exist

Answer 6

tablets
inserts
lozenges
films

Question 7

what type of semi solid mucoadhesive formulation exist

Answer 7

gel + paste
viscous liquid
gel forming liquids

Question 8

what are the advantages of a mucoadhesive delivery

Answer 8

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

Question 9

what are some specific features of mucoadhesive polymers

Answer 9

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

Question 10

what factors affect mucoadhesion

Answer 10

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

Question 11

what are second generation mucoadhesive materials

Answer 11

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