Factors Affecting Buccal Absorption
1. Physicochemical properties of the drug:
Lipophilicity, molecular size, ionization state, and solubility can impact absorption.
2. Enzymatic activity:
Enzymes in saliva or within the buccal mucosa can metabolize drugs, affecting their absorption.
3. Saliva flow rate:
Can affect drug dissolution and wash away the drug from the buccal cavity.
4. Buccal mucosa health:
Inflammation, ulcers, or other pathologies can influence absorption.
5. Presence of permeation enhancers:
Compounds that increase the permeability of the mucosa.
6. Formulation factors:
pH, viscosity, and presence of excipients
Advantages of Buccal Drug Delivery Systems:
1. Bypassing First-Pass Metabolism:
Drugs are directly absorbed into the systemic circulation, avoiding hepatic metabolism.
2. Enhanced Bioavailability:
Particularly for drugs that undergo significant first-pass metabolism.
3. Rapid Onset of Action:
Suitable for drugs needed for immediate relief.
4. Improved Patient Compliance:
Can be more comfortable and convenient than injections or oral pills .
5. Suitable for Unstable Drugs:
Avoids the acidic environment of the stomach.
6. Local Therapy:
Can be used for conditions like mouth ulcers or infections.
Limitations of Buccal Drug Delivery Systems:
1. Drug Limitations:
Only certain drugs (based on size, lipophilicity) are suitable.
2. Limited Drug Load:
Due to the small size of the delivery systems.
3. Saliva Dilution:
Can wash away the drug, affecting release and absorption.
4. Potential Irritation:
Some formulations might irritate the mucosa.
5. Patient Variability:
Differences in buccal pH, saliva production, and mucosal health can affect drug absorption and efficacy.
6. Discomfort:
Some formulations might cause discomfort or alter taste perception.
