1. Zero-Order Kinetic Release From Capsule Reservoirs through Semi-Permeable Polymer Membranes
Denise Bion, Matthew Blank, Dylan Freas, Craig Gambogi, Demetris Rotsides, Sadik Shahidain, Daniel Ye, Barbara Zhan
Dr. David Cincotta, Amanda Garfinkel

2. Controlled-Release Kinetics
Study of the rates of chemical processes
Most are naturally first or second-order
Zero-order processes usually do not occur naturally
“Pseudo” zero-order processes

3. Applications of Controlled- Release Kinetics
Very effective
medical treatment
Prevents drugs from reaching near-toxic levels (such as those in chemotherapeutic treatments)
Helps maintain
safe but effective concentrations

4. Microspheres (Nanyang Experiment)
Drug loaded into microspheres
Drug immobilized in membrane
Microsphere acts as an constant reservoir
Drug diffuses at a constant rate
Modeled on a macro-level using capsules

5. Polymers Long chains of repeating monomer units
Many properties affect permeability:
Chain length
Chain branching
Intermolecular forces
Different properties result in different diffusion rates

6. Fick’s Law
Fick’s Law governs the process of diffusion across a membrane
Constant concentration  pseudo-zero-order release

7. Hypothesis Goal: Create an apparatus to achieve zero-order release
Constant concentration  zero-order release
Goal: Create an apparatus to achieve zero-order release

8. Hansen Solubility Parameters
Ra2 = 4(δ D1 - δ D2) 2 + (δ P1 - δ P2) 2 + (δ H1 - δ H2) 2
RED > 1 : Insoluble
RED < 1 : Soluble

9. Methods and Material 1. Capsule Durability 2. Capsules and Glue
3. Membrane
VEGETABLE CAPSULES
GEL CAPSULES
Petri Dish
Membrane
Liquid
Liquid
Liquid

10. Final Experiment
Apparatus
Petri Dish
Membrane
Liquid
2 mL

11. Overview of Experiment
3 polymer membranes, 2 organic solvents, 2 types of capsules
9 combinations of solvent, capsule, and membrane tested
12-hour experimental window
Systems were massed every two hours

14. Areas for Improvement Rubber band seal
Cool down every two hours for massing
Larger range of data
Human error

15. Conclusion
Pseudo-zero-order release with capsules and membrane is possible
Many combinations exhibited strong, linear releases
Our model justifies microsphere experiment

16. Future Studies Capsules relevant to biological systems
Further experiments on controlling rate of release

17. Dr. David Cincotta, advisor
Acknowledgements
Dr. David Cincotta, advisor
Amanda Garfinkel, assistant
Dr. David Miyamoto, director
NJGSS and sponsors, providing the opportunity for this experience