Mucoadhesive dosage forms Flashcards
Routes of mucoadhesive dosage forms
Nasal cavity Oral e.g SL,buccal, gingival vaginal intravesical e.g bladder Ocular rectal
Advantages of mucoadhesive drug delivery?
Increased residence time increased bioavailablity avoids GIT effects eg FPM targeting particular body area - less systemic effects Reduced administration frequency Can terminate easier
What are the 2 stages of mucoadhesion
Contact- swelling, wetting
Consolidation - formation of non covalent bonds e.g H bonds, diffusion, penetration
What are we assessing for when assessing mucoadhesive dosage forms?
muco adhesion properties
biocompatability
What methods are used to assess mucoadhesion
Flow cell method - dosage form on tissue, washed with artificial body fluid- test liquid to see adhesion
Rotating cylinder - tissue and dosage form attached to cylinder, rotated in liquid mimicing stomach - measure time of detachment
Detachment forces/work of adhesion - testing detachment of a tablet
What is detachment force and work of adhesion?
Detachment force (A) is the amount of force needed to detach the dosage form,the higher the better
Work of adhesion (B) is the area under curve, if larger area - better adhesive properites
Name some good mucoadhesive polymers
Carboxymethylcellulose
Carbopol, polyacrylic acid, polycarbophil
Sodium alginate, chitosan, PAA (Basically all ionic polymers)
Are non ionic polymers good for mucoadhesion?
Some are fair e.g Gelatin, Dextran but not very good.
Are polyampholytes good for adhesion?
NO - conflicting charges
What are the main features of mucoadhesive polymers?
- hydrophilic
- mainly polyelectrolytes
- They have some hydrogen bonding groups e.g carboxyl, hydroxyl, amino
What factors affect adhesion?
Polymer molecular weight [mucoadhesive] chain flexibility pH presence of non mucoadhesive excipients
