The eye, as an organ, is equipped with several protective mechanisms, including tear production, rapid turnover rate of tears, presence of corneal epithelium, and enzymatic action in tears.
These mechanisms, while beneficial for safeguarding our vision, pose challenges for the effective delivery and prolonged retention of drugs to the eye.
Traditional ocular dosage forms, like eye drops, have limitations in terms of providing prolonged and targeted drug delivery.
This is where the importance of NDDS in B. Pharma comes into play.
Ocular drug delivery systems (ODDS) are designed to improve the therapeutic efficacy of drugs by increasing their corneal absorption, prolonging retention time, and targeting specific tissues or cells within the eye.
ODDS can be categorized into the following:
1. Topical Ocular Drug Delivery Systems:
These include gels, ointments, suspensions, and nanoparticle-based solutions. They are applied directly to the eye.
2. Posterior Ocular Drug Delivery Systems:
Designed to target the posterior segment of the eye, these include intravitreal injections, implants, and particulate systems.
3. Contact Lens Drug Delivery Systems:
These are contact lenses impregnated with drugs that provide a slow, controlled release when worn.
4. Mucoadhesive Ocular Drug Delivery Systems:
These systems use polymers to enhance the retention of drugs on the ocular surface.
Advantages of Ocular Drug Delivery Systems:
1. Prolonged Retention:
Enhanced residence time of drugs on the ocular surface.
2. Targeted Delivery:
Ensures delivery of the drug to specific parts or cells of the eye.
3. Improved Bioavailability:
Reduces wastage and increases the fraction of the drug reaching the desired site.
4. Reduced Side Effects:
By delivering drugs directly to the site of action, systemic side effects are minimized.
Disadvantages of Ocular Drug Delivery Systems:
1. Complex Formulation:
Requires sophisticated technology and know-how.
2. Potential Irritation:
Some formulations might cause irritation or allergies.
3. Cost:
Advanced drug delivery systems might be more expensive than traditional methods.
4. Invasiveness:
Techniques like intravitreal injections can be invasive and may pose risks of complications.
