The way in which chemical active substances or drugs are delivered has attracted increasing attention in the last two decades. Conventionally, a chemical active substance is given in a high dose at a certain time and the same dose is repeated several hours or days later. This is uneconomical and sometimes causes adverse side effects. Therefore, more and more attention has been paid to methods of delivering drugs continuously for a long period of time and in a controlled manner. The main method to solve the problem of controlled release (CR) is to incorporate chemical active substances into a polymer. This technology now covers many fields and includes pharmaceuticals, agricultural food applications, pesticides, cosmetics and household products. In the pharmaceutical field, in addition to polymers, an understanding of the physiological limitations of the human body is also important to build an appropriate controlled release system. The skin, gastrointestinal tract, nose and eyes are important parts of a controlled release system. A controlled release system will deliver the active substance to the target site with a controlled concentration within a desired time span. Understanding the polymer as a carrier and how the polymer interacts with the delivered active substance is the focus of controlled release technology. After completing this course, students are expected to be able to apply the principles of chemistry-biology-pharmaceuticals in designing controlled release systems. Topics to be studied are polymer selection for the manufacture of controlled release (CR) systems by understanding degradation and release profiles, manufacturing techniques and characterization of micro/nano particles as an introduction, and overall design of the manufacture of controlled release systems for certain cases.

• Polymeric Biomaterials That Are Easily Degradable

  • Overview of biodegradable polymers and their role in biomedical applications
  • Types of degradable polymers: natural and synthetic (e.g., polylactic acid, polycaprolactone)
  • Applications of biodegradable polymers in drug delivery and tissue engineering

• Various Methods for Drug Encapsulation and Bioactive Compounds in Nano/Microspheres

  • Techniques for encapsulating drugs and bioactive compounds:
    • Solvent evaporation
    • Emulsification-solvent diffusion
    • Coacervation
    • Spray drying
  • Advantages and challenges of nano/microspheres for controlled drug delivery

• Diffusion and Permeation

  • Principles of drug release: diffusion mechanisms in polymeric systems
  • Factors affecting drug diffusion: polymer type, molecular weight, and environmental conditions
  • Permeation through biological membranes and barriers

• Strategy for Controlled Release

  • Overview of controlled and sustained release systems in drug delivery
  • Strategies to control the release rate:
    • Diffusion-controlled release
    • Erosion-controlled release
    • pH-sensitive release
    • Temperature-sensitive release
  • Materials and technologies for controlled release systems

• Case Study

  • Real-world case studies of drug encapsulation and controlled release in clinical applications
  • Analysis of challenges and solutions in the development of polymeric drug delivery systems

• Describe the principle of controlled drug release or bioactive compound delivery for medical purposes.
• Utilize these principles to apply controlled drug release technology.

1. Juergen Siepmann et al. (Ed.), Fundamentals and Applications of Controlled Release Drug Delivery, Springer.
2. Clive Wilson & Patrick Crowley (Ed.), Controlled Release in Oral Drug Delivery, Springer.
3. Hong Wen & Kinam Park (Ed.), Oral Controlled Release Formulation Design and Drug Delivery, Wiley, 2010.
4. WM Saltzman, Drug Delivery: Engineering Principles for Drug Therapy, Oxford University Press, 2001.
5. Nissim Garti, Delivery and Controlled Release of Bioactives in Foods and Nutraceuticals, CRC Press, 2008.