A Review: Targeted Drug Delivery System

Abstract

This review highlights recent research on targeted drug delivery systems involving NCTD, focusing on passive, active, and physicochemical strategies. These systems aim to improve the drug’s bioavailability, enhance therapeutic effectiveness, increase targeting precision, and minimize side effects. The delivery methods covered include direct injection, jet injection, ultrasound, and iontophoresis many of which are adapted from transdermal drug delivery techniques. Direct injection through endoscopy, using needles, has been a standard clinical practice for over a hundred years. Jet injection, a needle-free approach where a high-speed liquid jet delivers drugs into tissues, has been tested in preclinical studies for administration into the buccal mucosa. Other advanced delivery systems involve polymer-drug conjugates and nanoparticles like liposomes, quantum dots, and dendrimers. Additional strategies include attaching therapeutic agents to \"targeting ligands,\" which can specifically bind to tumor-associated antigens. This review, therefore, concentrated on recent studies involving targeted drug delivery systems combined with NCTD, covering passive and active targeting methods, as well as this review highlights recent research on targeted drug delivery systems involving NCTD, focusing on passive, active, and physicochemical strategies.

Introduction

Targeted Drug Delivery Systems (TDDS) are advanced therapeutic approaches designed to deliver drugs directly to specific tissues or cells in the body. This maximizes therapeutic effects while minimizing side effects by avoiding unnecessary exposure of healthy tissues to the drug.

2. Why Targeted Drug Delivery Matters

• Traditional drugs often affect the whole body, leading to unwanted side effects.

• TDDS enhances drug action at the disease site and reduces drug waste and toxicity.

• The approach aligns with the goal of personalized, efficient, and safer therapy.

3. Advantages of TDDS

• Higher efficacy at the target site.

• Reduced side effects on healthy tissue.

• Lower dosages needed due to improved targeting.

• Improved patient compliance due to fewer side effects and dosing.

• Controlled/sustained drug release for long-term therapeutic levels.

• Ability to bypass biological barriers (e.g., blood-brain barrier).

• Useful for difficult diseases like cancer and autoimmune conditions.

4. Disadvantages of TDDS

• High cost of research and development.

• Complex manufacturing processes.

• Not suitable for all drugs or diseases.

• Risk of immune reactions to carriers like nanoparticles.

• Potential instability of drug carriers before reaching the target.

• Regulatory hurdles due to new and complex technologies.

• Possibility of targeting errors, which can lead to toxicity.

5. Technologies Used in TDDS

• Nanoparticles – engineered particles for precise delivery.

• Liposomes – vesicles that encapsulate and control drug release.

• Micelles – nanostructures for hydrophobic drug delivery.

• Antibody-Drug Conjugates (ADCs) – target-specific combinations used in cancer.

• Dendrimers – highly branched polymers for multi-drug delivery.

• Magnetic nanoparticles – directed to target tissues using magnetic fields.

6. Applications of TDDS

• Cancer Treatment: Delivers chemotherapy directly to tumors (e.g., Herceptin for HER2-positive breast cancer).

• Gene Therapy: Delivers mRNA or DNA (e.g., lipid nanoparticles in COVID-19 vaccines).

• Infectious Diseases: Focused delivery of antibiotics or antivirals to infected tissues.

• Neurological Disorders: Crosses the blood-brain barrier for brain diseases like Alzheimer’s.

• Autoimmune Diseases: Targets inflamed tissues in diseases like rheumatoid arthritis.

• Diabetes: Controlled insulin release using nano/microparticles.

• Ocular Diseases: Delivers drugs to hard-to-reach eye tissues.

• Pain Management: Localized analgesic delivery for arthritis or post-surgical pain.

• Vaccines: Improves immune response via targeted delivery to immune cells.

• Cardiovascular Diseases: Directs drugs to blood vessels to prevent atherosclerosis.

7. Key Causes for the Development of TDDS

• Minimizing systemic toxicity by avoiding drug exposure to healthy tissues.

• Enhancing drug effectiveness by concentrating it at the disease site.

• Overcoming biological barriers like the blood-brain barrier.

• Reducing drug resistance by ensuring higher local drug concentrations.

• Improving patient adherence through less frequent, sustained-release dosing.

• Enabling personalized medicine, tailoring treatment to individual disease profiles.

• Avoiding invasive procedures, providing non-invasive delivery alternatives.

• Activating drugs in specific disease environments, like acidic tumor sites.

• Preventing drug degradation in the bloodstream.

• Treating chronic diseases with long-term, controlled-release therapies.

Conclusion

The ability to deliver drugs to specific locations has allowed targeted drug delivery to advance quickly. Because no drug delivery system can effectively deliver drugs to the exact site of action, this results in a lower injection dose and a significant reduction in side effects that were previously more noticeable. Numerous nanoparticles have been approved for clinical use, and while they are still in the development stages, they hold the key to the future of drug-targeting. The use of nanotechnology in drug delivery has improved the delivery of medication in particular. Similar outcomes have also been achieved with a number of other strategies. All of them present the brilliant future of targeted drug delivery .Targeted drug delivery systems are a groundbreaking development in therapeutic medicine that provide previously unheard-of control over drug distribution and release.

References

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Copyright

Copyright © 2025 Akanksha Satish Adhav, Pooja Vitthal Chopade, Reshma Laxman Shinde, Shreya Pankaj Patil. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.