
Drug delivery systems (DDS) are a cornerstone of modern medicine, enabling the precise targeting and controlled release of therapeutic agents. Among the plethora of materials studied for DDS, chitin and its derivative, chitosan, have emerged as highly promising due to their unique biocompatibility, biodegradability, and versatility. These natural polymers, derived primarily from the exoskeletons of crustaceans, insects, and fungal cell walls, are reshaping the future of drug delivery.
Chitin and Chitosan: Chemical and Functional Properties
Chitin is a naturally occurring polysaccharide composed of β-(1→4)-linked N-acetyl-D-glucosamine units. Upon deacetylation, it transforms into chitosan, which boasts superior solubility and functional properties in acidic conditions. The degree of deacetylation (DD) and molecular weight of chitosan play critical roles in determining its performance in DDS applications (Yang & Hon, 2010).
Key properties that make chitosan a preferred material in drug delivery include:
Biocompatibility: It is non-toxic and well-tolerated by biological systems.
Mucoadhesion: Chitosan's positive charge interacts with negatively charged mucosal surfaces, improving drug retention and absorption.
Biodegradability: Enzymatic degradation into non-toxic byproducts ensures minimal environmental and physiological impact.
Chemical Versatility: Functional groups on chitosan allow for modifications, enabling tailored drug release profiles.
Applications of Chitin and Chitosan in Drug Delivery Systems

1. Oral Drug Delivery
Oral administration remains the most patient-friendly drug delivery route. Chitosan's mucoadhesive properties enhance the absorption of drugs through the gastrointestinal tract, particularly for peptides and proteins that are otherwise poorly absorbed. Additionally, chitosan nanoparticles (CNPs) can protect drugs from degradation in the stomach's acidic environment, allowing for sustained release (Bernkop-Schnürch & Dünnhaupt, 2012).
-Insulin Delivery
Chitosan nanoparticles have been investigated as carriers for insulin. Studies show that encapsulating insulin in chitosan enhances its stability and bioavailability, making it a viable alternative to injections (Wong, 2009).
2. Transdermal Drug Delivery
Chitosan's film-forming ability and its compatibility with human skin make it an excellent candidate for transdermal patches. Its ability to interact with the skin’s surface can increase drug permeability and bioavailability. Additionally, chitosan-based hydrogels are being explored for wound healing applications, where they can deliver drugs directly to the site of injury (Ma et al., 2022).

3. Targeted Drug Delivery
Chitosan's chemical modifiability allows for the conjugation of targeting ligands, such as folic acid, antibodies, or peptides. This ensures the delivery of drugs to specific cells or tissues, such as cancer cells. Chitosan-coated liposomes and nanoparticles are being used in cancer therapies to enhance drug accumulation in tumour sites (Ghaz-Jahanian et al., 2015).
-Anticancer Drug Delivery
Chitosan nanoparticles loaded with doxorubicin, a common chemotherapy agent, demonstrated enhanced cytotoxicity against cancer cells while reducing systemic toxicity (Janes et al., 2001).
4. Gene Delivery
Chitosan's cationic nature facilitates its interaction with negatively charged DNA or RNA molecules, forming stable complexes that protect genetic material from enzymatic degradation. These complexes are being studied for their potential in gene therapy and RNA-based vaccines (Duceppe & Tabrizian, 2010).

5. Intranasal Drug Delivery
The nasal route offers a non-invasive alternative for systemic drug delivery, bypassing the blood-brain barrier. Chitosan’s mucoadhesive properties improve drug retention in the nasal cavity and enhance the uptake of large molecules such as peptides and vaccines (Omidian et al., 2024).
6. Vaccine Delivery
Chitosan’s ability to act as an adjuvant makes it a valuable material for vaccine delivery. It can stabilize antigens, enhance their uptake by immune cells, and improve the overall immune response (Illum et al., 2001).
Innovations in Chitosan-Based Drug Delivery
Stimuli-Responsive Systems: Chitosan can be modified to respond to external stimuli such as pH, temperature, or light, enabling on-demand drug release (Wang et al., 2023).
Dual-Drug Delivery Systems: Chitosan-based systems can co-deliver two drugs with complementary effects, improving therapeutic outcomes (Meng et al., 2013).
3D Printing Applications: Chitosan hydrogels are being explored for fabricating personalised drug delivery systems using 3D printing technologies (Yang et al., 2022).
Regulatory and Environmental Considerations
The U.S. FDA and European Medicines Agency (EMA) recognise chitosan as Generally Recognized as Safe (GRAS). Its renewable and biodegradable nature aligns with global sustainability goals, making it an attractive choice for pharmaceutical companies focused on reducing their environmental impact.
While chitosan derived from crustaceans, the traditional source, carries a potential risk of allergic reactions, particularly for those with shellfish allergies, the highly purified chitosan used in most drug delivery systems generally presents a low risk (Muzzarelli, 2010).
At Entoplast, we take this a step further, addressing allergy concerns and promoting sustainability by utilising Black Soldier Fly (BSF) as a source of chitosan. This innovative approach not only reduces the risk of shellfish-related allergies but also contributes to a circular economy and reduces reliance on crustacean harvesting.
Why Choose Entoplast for Chitosan-Based Solutions?
Entoplast is at the forefront of innovation in biopolymer applications, specialising in chitin and chitosan technologies. Our commitment to quality, sustainability, and tailored solutions ensures that we meet the diverse needs of the pharmaceutical and medical industries. Whether you're developing advanced drug delivery systems or exploring novel applications, Entoplast provides the expertise and materials to help you succeed.
Speak to our team at hello@entoplast.com to learn more about our chitin and chitosan solutions. Partner with us and shape the future of drug delivery.
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