38
Cut single-layer semipermeable cellulose ester membrane to a suitable size to cover the diffusion area of the Franz cells or dialysis
devices. Soak in degassed receptor solution for at least 6 h or overnight. Membrane must be in equilibrium with the receptor solution prior to the test. Do not let membrane become dry.
3 Methods
1. Mount receptor compartments of vertical Franz diffusion cells
on stage magnetic stirring apparatus or suitable supportive
apparatus to hold each cell in place. Point the sampling ports
at an angle out to the side so samples can be easily collected.
2. Place a magnetic stirring bar in each cell. Ensure that suitable
size of magnetic stirring bars is used.
3. Pre-fill each receptor compartments with deaerated receptor
solution until the cell is about 90% filled (see Note 3).
4. Start magnetic stirring apparatus at constant speed (see Note
4) to ensure that there are no bubbles in the cell especially on
the glass wall of receptor compartment. If bubbles are noticed,
run the stirrer at high speed for a few seconds or use a sampling needle to release bubbles.
5. Continue to fill receptor compartment (with receptor solution)
until there is a positive meniscus covering the top of the cell.
6. Carefully mount a single-layer-soaked membrane using a pair
of tweezers (see Note 5). Inspect underneath the mounted
membrane for bubbles. Always ensure that the stirring is off
before placing the soaked membrane on the cells.
7. Assemble donor and receptor compartments, pinch together
with pinch clamp and ensure that there is no leakage. Soaked
membrane must completely cover the diffusion area of cell
and the two compartments aligned.
8. Start the stirrers and pipette tested solution into donor compartment. Start the timer for the experiment and cover donor
compartment with adhesive seal film (see Note 6). It is recommended to run each test solution at least triplicate.
9. At the sampling time point (see Note 7), withdraw an appropriate
volume of receptor medium from close to the bottom of receptor
compartment through sampling port using syringe connected
with suitable length needle. Replace immediately with an equal
volume of degassed receptor solution. Confirm that there are no
bubbles underneath membrane during sampling and refilling.
10. Analyze the content of guest compound in sampling solutions
with an appropriate analytical method (e.g., HPLC).
2.4 Semipermeable
Membrane
3.1 Permeation
Studies
3.1.1 Franz
Diffusion Cells
Phennapha Saokham and Thorsteinn Loftsson
Cut single-layer semipermeable cellulose ester membrane to a suitable size to cover the diffusion area of the Franz cells or dialysis
devices. Soak in degassed receptor solution for at least 6 h or overnight. Membrane must be in equilibrium with the receptor solution prior to the test. Do not let membrane become dry.
3 Methods
1. Mount receptor compartments of vertical Franz diffusion cells
on stage magnetic stirring apparatus or suitable supportive
apparatus to hold each cell in place. Point the sampling ports
at an angle out to the side so samples can be easily collected.
2. Place a magnetic stirring bar in each cell. Ensure that suitable
size of magnetic stirring bars is used.
3. Pre-fill each receptor compartments with deaerated receptor
solution until the cell is about 90% filled (see Note 3).
4. Start magnetic stirring apparatus at constant speed (see Note
4) to ensure that there are no bubbles in the cell especially on
the glass wall of receptor compartment. If bubbles are noticed,
run the stirrer at high speed for a few seconds or use a sampling needle to release bubbles.
5. Continue to fill receptor compartment (with receptor solution)
until there is a positive meniscus covering the top of the cell.
6. Carefully mount a single-layer-soaked membrane using a pair
of tweezers (see Note 5). Inspect underneath the mounted
membrane for bubbles. Always ensure that the stirring is off
before placing the soaked membrane on the cells.
7. Assemble donor and receptor compartments, pinch together
with pinch clamp and ensure that there is no leakage. Soaked
membrane must completely cover the diffusion area of cell
and the two compartments aligned.
8. Start the stirrers and pipette tested solution into donor compartment. Start the timer for the experiment and cover donor
compartment with adhesive seal film (see Note 6). It is recommended to run each test solution at least triplicate.
9. At the sampling time point (see Note 7), withdraw an appropriate
volume of receptor medium from close to the bottom of receptor
compartment through sampling port using syringe connected
with suitable length needle. Replace immediately with an equal
volume of degassed receptor solution. Confirm that there are no
bubbles underneath membrane during sampling and refilling.
10. Analyze the content of guest compound in sampling solutions
with an appropriate analytical method (e.g., HPLC).
2.4 Semipermeable
Membrane
3.1 Permeation
Studies
3.1.1 Franz
Diffusion Cells
Phennapha Saokham and Thorsteinn Loftsson