MODIFIED-RELEASE DRUG PRODUCTS AND TARGETED DRUG DELIVERY SYSTEMS

Modified-release (MR) drug products and targeted drug delivery systems represent advanced pharmaceutical technologies designed to optimize therapeutic outcomes by controlling the rate, timing, and site of drug release. These systems address limitations of conventional dosage forms, such as frequent dosing, fluctuating plasma levels, and systemic side effects, by enhancing drug bioavailability, patient compliance, and site-specific action.

Modified-release formulations include:

• Extended-release (ER): Maintain therapeutic drug levels over prolonged periods, reducing dosing frequency.
• Delayed-release (DR): Release the drug at a specific time or location, often using enteric coatings to bypass the stomach.
• Repeat-action and pulsatile systems: Deliver multiple doses at predetermined intervals.

Targeted drug delivery systems aim to:

• Direct drugs to specific tissues or cells, minimizing off-target effects.
• Utilize carriers such as liposomes, nanoparticles, and biodegradable polymers to enhance selectivity.
• Respond to physiological triggers (e.g., pH, enzymes, temperature) for controlled activation.

Mechanisms of drug release include:

• Matrix systems (hydrophilic, hydrophobic, lipid-based)
• Osmotic pumps
• Microencapsulation and diffusion-controlled systems

These technologies are particularly valuable in treating chronic diseases, cancer, and inflammatory conditions, where precision and sustained action are critical. The integration of biocompatible materials, smart polymers, and nanotechnology continues to expand the potential of MR and targeted delivery systems, paving the way for personalized and more effective therapies.