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

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

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

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

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

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

Hypothesis Goal: Create an apparatus to achieve zero-order release Constant concentration  zero-order release Goal: Create an apparatus to achieve zero-order release http://apollo.lsc.vsc.edu/classes/met130/notes/chapter7/cond_pure_sat.html

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

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

Final Experiment Apparatus Petri Dish Membrane Liquid 2 mL

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

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

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

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

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