1. Define an emulsion. In your definition discern between an oil in water and a water in oil emulsion with descriptions of the dispersed and dispersing phase. Give an example of how to identify the type of emulsion and finally list a reason to formulate a drug as an emulsion.

2. List the four things necessary to make an emulsion. I want to disperse 10 mls of oil with an average droplet size of 1 m in water. The change in surface area would be 6x105 cm2. If the o/w is 57 dyne/cm how much energy would be necessary to make the emulsion? What can be done to reduce the energy required to emulsify the components?

3. What is the HLB and why would a high HLB be desired to form an oil in water emulsion?

4. Describe the four types of emulsion instability. In your answer distinguish between irreversible instability and reversible instability (i.e. what is the difference between flocculation and coalescence?). Also illustrate

a. how decreasing particle size slows down the process of creaming

b. why oil in water emulsion demonstrate upward creaming and water in oil

emulsions demonstrate downward creaming

5. List and describe the differences between a microemulsion and an emulsion (macroemulsion). In your answer explain how a microemulsion forms spontaneously.

6. What is the difference between a microemulsion and a micelle? Why are micelles poor drug delivery vehicles?

7. What are SEDDS and SMEDDS? In your answer make sure you differentiate between the two including why a SMEDD might demonstrate better absorption characteristics than a SEDD. What are the advantages of these systems over a traditional emulsion system?

answer all parts , will give thumbs up! :)