Chitosan as excipient

What is Chitosan?

Chitosan, a biopolymer derived from chitin, has gained significant attention in various industries, particularly in pharmaceutical applications. With its unique properties and versatile nature, chitosan has found a wide range of uses, ranging from drug delivery systems to wound healing.

Composition and properties of Chitosan

Chitosan is derived from chitin, a natural polysaccharide found in the exoskeletons of crustaceans, insects, and the cell walls of fungi. Chitin is composed of repeating units of N-acetylglucosamine, and through deacetylation, chitosan is formed. The degree of deacetylation (DD) defines the proportion of N-acetylglucosamine units converted to glucosamine, affecting the physicochemical properties of chitosan.

Properties:

  1. Biocompatibility: Chitosan is biocompatible, making it suitable for various biomedical applications, including drug delivery systems and wound healing.
  2. Mucoadhesiveness: Chitosan exhibits mucoadhesive properties, allowing it to adhere to mucosal surfaces. This property is advantageous for drug delivery systems targeting mucosal tissues.
  3. Antimicrobial Activity: Chitosan has inherent antimicrobial properties, making it useful in wound dressings, coatings for medical devices, and as an antimicrobial agent in pharmaceutical formulations.
  4. Film-Forming Ability: Chitosan can form films, which is beneficial for creating controlled-release drug delivery systems and wound dressings.

Chitosan manufacturing

The production of chitosan involves a series of steps, primarily deacetylation of chitin. Chitin is typically extracted from crustacean shells (shrimp and crab) or fungal sources. The extracted chitin undergoes deacetylation, usually using alkaline hydrolysis, resulting in chitosan. The production process influences the final properties of chitosan, such as molecular weight and degree of deacetylation.

Synthesis Routes:

Chitosan can be synthesized through various routes, including chemical, enzymatic, and microbial methods. Chemical methods involve deacetylation using alkaline substances, while enzymatic methods use chitinase enzymes to catalyze the reaction. Microbial methods involve the action of microorganisms on chitin to produce chitosan. Each route offers distinct advantages and may influence the properties of chitosan.

Figure 1 Structural formula of Chitosan

Stability and Degradation of Chitosan

Chitosan exhibits good stability under various conditions. However, its degradation can occur through enzymatic hydrolysis, especially by chitinase enzymes. Understanding the degradation kinetics is crucial for designing chitosan-based formulations with controlled release profiles.

Advantage and disadvantages of Chitosan

Advantages:

  • Biodegradability: Chitosan is biodegradable, making it environmentally friendly.
  • Versatility: Its versatile nature allows for various modifications to tailor its properties for specific applications.
  • Low Toxicity: Chitosan is generally considered safe with low toxicity, enhancing its suitability for pharmaceutical and biomedical applications.
  • Drug Delivery Systems: Chitosan’s mucoadhesive and biocompatible properties make it an excellent candidate for drug delivery systems, facilitating targeted drug release.
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Disadvantages:

  • Source Limitations: Chitosan is primarily derived from crustacean shells, which may pose challenges related to sustainability and potential allergenic reactions.
  • Processing Challenges: The extraction and purification processes can be complex and may involve the use of chemicals.
  • Varied Properties: The properties of chitosan can vary based on source, degree of deacetylation, and production methods, requiring careful consideration for specific applications.

In conclusion, chitosan’s unique properties make it a promising material for pharmaceutical applications. Ongoing research continues to explore its potential in drug delivery systems, wound healing, and other biomedical fields. As technology advances, addressing challenges related to sourcing and processing will likely enhance the utilization of chitosan in the pharmaceutical industry.

Chitosan Characterization Services

Excipia is an independent contract service platform that focuses on the physicochemical characterization of pharmaceutical excipients and food ingredients like chitosan; as a pure substance, as a raw material or when processed into end products.

More than 25 years in the development of pharmaceutical formulations have taught us that the limited information available on an excipient Certificate of Analysis (CoA) often falls short of explaining observed product or excipient characteristics and that more in-depth knowledge of the actual chemical excipient composition is essential to meet and understand specific formulation challenges.

Over the past 15 years, Excipia analytical scientists have spent tens of thousands of hours establishing unique, specific analytical and physicochemical methods with ingenious sample preparation techniques to characterize polysaccharides and other pharmaceutical excipients.

In these years we have gained a lot of knowledge about many excipients, their properties and exact composition, the difference between batches, qualities, grades, and manufacturers, how to quantify them in medicines and how they can best be used in a formulation.

Excipia offers fast and flexible hands-on cellulose characterization services to reveal and compare hidden properties like:

    • the presence of potential reactive impurities or functional groups,
    • reducing power of excipients,
    • degradation products and related substances,
    • relative molecular weight distributions,
    • and many other excipient characteristics.
     

In addition, Excipia can help users of excipients to pick the most appropriate manufacturer, select the most suitable grade for their finished dosage form, or define customized cellulose specifications to control product performance, quality and safety.

Welcome to Excipia, a service platform of Avivia, dedicated to the composition, quality and quantity of excipients in medicinal products.

Discover our unique services such as quantitative excipient analysis, identification, selection or specific formulation development support. Don’t forget to check out our case studies.

Feel free to contact us using the “Contact”  button or by sending a message to Excipia@avivia.nl.

Menno Wiltink
Founder of Excipia.

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Excipia, a division of Avivia BV

 Excipia as dedicated excipient knowledge platform is a division of Avivia BV, a Dutch independent specialized pharmaceutical development company that operates a hybrid business model combining CRO service activities with internal product development programs. The other complementary platforms of Avivia are Pharmaceutical R&D, Analytical R&D, and Biorelevant Dissolution Testing. For more information about Avivia and its pharmaceutical development CRO services, please visit the Avivia website.