2.5. Microbiological stability
One gram of emulsion was dispersed in a 4 ml sterile Ringer’s
solution containing 0.25% tween 80. Six dilutions were made
in the same dispersing vehicle, and 0.1 ml was plated out on
the appropriate solid medium using the surface viable method.
Colonies were counted after the incubation and all operations
were carried out in duplicates (ISO NF- 21148, 2000).