Lesson Summary:

Particles in Drug Delivery:
- Emulsion is formed by applying mechanical energy to disrupt the interface between two phases to such an extent that droplets are formed.
- Emulsion sizes and stability directly effect the size and internal architectures of the particles formed

Solvent Evaporation: Typical W/O/W Double Emulsion Process
- Homogenize/sonicate first emulsion
- Homogenize/sonicate second emulsion
- Organic Solvent Evaporation
- Microsphere separation and lyophilization

Parameters Affecting Particles:
- Polymer type and molecular weight
- Polymer concentration in the oil phase
- Type of drug and method of incorporation
- Organic solvent used and polymer solubility
- Type and amount of surfactant in external phase
- Internal aqueous phase/ Organic solvent ratio
- Rate of stirring and type of mechanical force
- Evaporation rate/ Temperature/ Pressure
Particle Synthesis:
-Spray drying
- Gelation
- Hot Melt
- Novel Methods (microparticle synthesis)

Nano- and Micro Particles:
Acts as a controlled release depot system similar to matrices, reservoirs or hydrogels
Decreasing the non-specific delivery of the drug to non-target tissue
Injectable
Convenient way for delivering large hydrophilic molecules inside cells
Particles can be adapted for targeted delivery to cells and tissues
Improving the stability of the drug in vivo
Improving shelf life of the product