Dear Pharmacist,

I suggest to assist the stirring with heat or/and use more portion of the solvent (200 mg in 30 mL instead of 200 mg in 20 mL).

Rafik

Dear Pharmacist,

Solubility

1 g of EUDRAGIT® RL 100 / RS 100 dissolves in 7 g aqueous methanol, ethanol and

isopropyl alcohol (containing approx. 3% water), as well as in acetone, ethyl acetate and methylene chloride to give clear to cloudy solutions. EUDRAGIT®

RL 12,5 and EUDRAGIT® RS 12,5 are miscible with these solvents in a ratio of 1:1.

This means you dissolve 1 gram of EUDRAGIT® RS 100 in 7 g of dichloromethane at room temperature. The resulted solution will be clear to cloudy solution.

For more details, see attached file.

Hoping this will be helpful,

Rafik

Dear professor,

Thank you. I have tried many times to dissolve 200 mg of Eudragit RS  100 in 20 ml of Dichloromethane but even after 1 hour of magnetic stirring, I see a lot of Eudragit RS 100 particles in Dichloromethane.

Regards

Dear professor,

Thank you. I have tried many times to dissolve 200 mg of Eudragit RS  100 in 20 ml of Dichloromethane but even after 1 hour of magnetic stirring, I see a lot of Eudragit RS 100 particles in Dichloromethane.

Regards

Dear professor,

Thank you. I have tried many times to dissolve 200 mg of Eudragit RS  100 in 20 ml of Dichloromethane but even after 1 hour of magnetic stirring, I see a lot of Eudragit RS 100 particles in Dichloromethane.

Regards

Dear Pharmacist,

I suggest to assist the stirring with heat or/and use more portion of the solvent (200 mg in 30 mL instead of 200 mg in 20 mL).

Rafik

Thank you.

Regards