Everything You Need to Know About the Manufacturing of Smart Drug Delivery Systems

Smart drug delivery systems deliver drugs or active pharmaceutical ingredients (APIs) to specific areas in the human body. They exhibit high therapeutic efficiency and safety by controlling the drug release rate and time. Before the introduction of smart drug delivery systems, traditional delivery systems, such as pills, tablets and syrups, were used. However, these systems have several disadvantages, such as imbalanced biodistribution, high dosage and uncontrolled drug release. 

Smart drug delivery systems overcome several disadvantages of traditional drug delivery systems. These advanced systems are designed to target specific areas within the body and deliver medication precisely where it’s needed. This improves the overall therapeutic efficiency, reduces toxicity, and decreases side effects. 

In recent years, smart drug delivery systems have attracted considerable research attention owing to their efficacy, ease of use and biocompatibility. Among the various drug delivery systems explored, a few have garnered considerable research focus.

This article details five smart drug delivery systems that have garnered the most research interest in recent years.

Top five smart drug delivery systems

Nanoparticle-based drug delivery systems 

Nanoparticle-based drug delivery systems utilise nanomaterials as carriers to transport therapeutic molecules directly to the targeted areas. The API is encapsulated by nanoparticles and released under a specific stimulus. Various smart drug delivery systems based on nanomaterials and nanoparticles have been developed for treating cancer, cardiovascular diseases, and neurological diseases.

Advantages:

• They increase the water-solubility of water-insoluble formulations.
• They can reduce the side effects of formulations.
• They have the potential for controlled and sustained drug release.

Disadvantages:

• They exhibit potential toxicity in humans.
• They require complex manufacturing processes.
• The response of these systems is difficult to reproduce.

Liposome-based drug delivery systems

Liposomes are lipid bilayer vesicles that encapsulate the formulation. Owing to the encapsulation, liposomes can easily prevent any damage to the drug and ensure a controlled release. Liposomes can respond to stimuli such as pH, light or temperature, ensuring the release of the formulation only when it contacts the target area. Owing to the liposomal covering, the human body can easily absorb the formulation. 

Various liposome-based drug delivery systems have been developed:

1. Doxil, also known as liposomal doxorubicin, is a chemotherapy used to treat breast cancer. 
2. AmBisome, also known as amphotericin B liposomal, is used to treat fungal infections.

Advantages:

• It increases the drug solubility in the body.
• It has low toxicity.

Disadvantages:

• It cannot maintain stability during transportation and storage.
• It has a high cost of production.

Magnetic nanoparticle-based drug delivery systems

Magnetic nanoparticle-based drug delivery systems utilise magnetic nanoparticles to deliver the target formulation. Similar to nanoparticle-based drug delivery systems, the formulation is encapsulated within the material. However, their mechanism of action is different. In this type of drug delivery system, the particles are directed to the target area by an external electric field. Upon reaching the area, the electric field intensity is changed or another external stimulus is applied to release the formulation. Magnetic nanoparticle-based drug delivery systems have been used to treat various ailments. For example, magnetic iron oxide nanoparticles have been used to treat liver cancer.

Advantages 

• It allows control over the transportation of the drug.
• Magnetic material allows imaging of medication within the human body.

Disadvantages 

• Various regulatory approvals are required for using a magnetic material.
• Magnetic materials may be toxic to humans.

Micelles for Drug Delivery 

Micelles are colloidal substances formed using amphiphilic surfactants in an aqueous solution. Micelles allow the dissolution of hydrophobic drugs inside the body even when they are not water soluble outside the body. The formulation is usually encapsulated within the micelle, which then carries it to the target organ. Like other smart drug delivery systems, upon contacting a target stimulus, the micelle bursts and the formulation is exposed to the blood. Some micelles that have been used for drug delivery include the plutonic micelles, which have been used for doxorubicin delivery, and polymeric micelles, like encapsulate paclitaxel micelles for cancer therapy.

Advantages

• It is quickly absorbed because of its small size (10-100 nanometers).
• It is cost-effective.
• It improves the stability and solubilization of hydrophobic drugs.

Disadvantages

• The stability of micelles changes with changes in the dilution and temperature.
• Micelles are rapidly cleared from surfaces if not designed optimally.

Stimuli-responsive hydrogel drug delivery systems 

Stimuli-responsive hydrogel drug delivery systems release the drug in response to a specific internal or external trigger. This ensures the controlled release of bioactive molecules and therapeutic drugs. These systems can be designed to be responsive to pH, temperature, dilution, salt concentration, etc. For example, pH-responsive hydrogels have been used to deliver insulin in human bodies.

Advantages

• The drug is released only under target conditions so there are no accidents.
• It reduces side effects.

Disadvantages

• It is complex to create a material responsive to specific triggers.
• The hydrogel may deteriorate over time.

Bottom line

Smart drug delivery systems are expected to have a significant impact on the pharmaceutical sector. As new smart delivery systems are developed, we can expect the therapeutic efficacy and efficiency to increase. In recent years, various smart drug delivery systems have been studied by diverse research teams. While many of these research efforts have yielded positive results, these technologies have yet to be translated into clinical trials and large-scale production. In the years to come, we can expect new developments in these fields, which will revolutionise the way we approach disease treatment.

FAQs

1. What role do magnetic fields play in magnetic nanoparticle drug delivery systems?

Magnetic fields are used in combination with magnetic nanoparticles to promote drug release from thermally sensitive nanocarriers. Magnetic fields guide magnetic nanoparticles to specific sites of the body. 

2. Can smart drug delivery systems be used for all types of diseases treatment?

No, while smart drug delivery systems are promising for various treatments, they are not suitable for all therapies. They are ideal for treatments where the medication needs to be delivered to a specific organ in the body. For example, in breast cancer, the formulation needs to be delivered specifically to the breast and not other parts.

3. How expensive are smart drug delivery systems?

Smart drug delivery systems may be more expensive than traditional drug delivery systems. However, they have several advantages: higher efficacy, higher effective dosage and fewer side effects.