Apparatus and method for preparing microparticles using liquid-liquid extraction

A method of preparing microparticles, comprising:

• forming an emulsion, the emulsion comprising a first phase that comprises a polymer, an active agent, and a solvent, and a second phase;
• separating a portion of the second phase from the emulsion to form a separated second phase;
• and
• replacing the separated second phase in the emulsion with a quantity of a solution.

A method of preparing microparticles, comprising:

• forming an emulsion, the emulsion comprising a first phase that comprises a polymer, an active agent, and a solvent, and a second phase;
• maintaining a separation between the emulsion and an extraction liquid;
• and
• extracting the solvent into the extraction liquid.

A method of preparing microparticles, comprising:

• forming an emulsion, the emulsion comprising a first phase that comprises a polymer and a solvent, and a second phase;
• separating a portion of the second phase from the emulsion to form a separated second phase;
• extracting from the separated second phase at least a portion of the solvent present in the separated second phase to form an extracted separated second phase;
• and
• returning the extracted separated second phase to the emulsion.

A method of preparing microparticles, comprising:

• forming an emulsion, the emulsion comprising a first phase that comprises a polymer and a solvent, and a second phase;
• separating a portion of the second phase from the emulsion to form a separated second phase;
• and
• replacing the separated second phase in the emulsion with a quantity of a solution.

A method of preparing microparticles, comprising:

• forming an emulsion, the emulsion comprising a first phase that comprises a polymer and a solvent, and a second phase;
• maintaining a separation between the emulsion and an extraction liquid;
• and
• extracting the solvent into the extraction liquid.