Mucoadhesjve Dosage Form Flashcards
What are the mucosal routes of drug administration?
Vaginal, Rectal, Intravesical, Oral cavity (Buccal, gingival and sublingual), Nasal, Oral, Ocular, Oesophageal
Define mucoadhesion.
Interfacial force interactions between synthetic or natural polymeric materials serving as a dosage form and a mucus layer that covers a mucosal tissue.
What are the functions of mucosal membranes/mucosa?
- Protection of epithelial cells from physical and chemical destruction
- Lubrication
- Wetting
- Modulation of water content in the underlying tissue
What is the mechanism of stomach protection by mucus gel?
Gastric mucus forms a protective layer over the epithelium and acts as a diffusion barrier.
What are the characteristics of mucosal surfaces?
- Dynamic surface that is reformed continuously through the secretion of mucins
- Relatively short life-time
- Efficient semi-permeable barrier system
How long does clearance take on different mucosal surfaces?
- 5.0-7.7 min on ocular surface
- 20 min in the respiratory tract
- 4-6 h in the gastrointestinal tract
List the types of mucoadhesive formulations.
- Solid formulations (Tablets, Inserts, Lozenges, Films)
- Semi-solid and liquid formulations (Gels and pastes, Viscous liquids, Gel-forming liquids)
What are the advantages of mucoadhesive delivery?
- 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 metabolism associated with GI tract
What are the specific features of mucoadhesive polymers?
- Hydrophilic or water-soluble polymers
- Negatively- or positively-charged groups
- Strong hydrogen bonding groups (e.g., carboxyl, hydroxyl, amino-groups)
What factors influence mucoadhesion?
- Molecular weight of polymers
- Concentration of mucoadhesive polymer in dosage form
- Chain flexibility / Cross-linking density of polymers
- pH
- Presence of non-mucoadhesive co-excipients
What is an example of a second-generation mucoadhesive material?
Polymeric thiomers.
What are second generation mucoadhesive materials
- Materials, whose mucoadhesive properties were enhanced with chemical modification
- They enhance mucoadhesive properties by forming bonds with molecules present on mucosal surfaces.
True or False: Second-generation mucoadhesives are all commercialized.
False.
What methods are used to evaluate mucoadhesive properties?
- Tensile method
- Flow-through method
Fill in the blank: The _______ in the mammalian stomach is concentrated enough to digest the stomach itself.
HCl
