Preservatives-2

DEAL CHARACTERS OF PRESERVATIVES :

1. Should be effective against different types of organisms.
2. Should be effective at as low a concentration as possible.
3. Should not interat with the other ingredients.
4. Should be effective in the entire Ph range in which the product is likely to be used.
5. Should be soluble so as to reach minimum inhibitory concentration.
6. Should have sustained action.
7. Should non-irritant and non-toxic etc.,

For naldehyde and formalin are used as preservatives in shampoos.

Most preferred preservatives are p-hydroxy benzoates. They have a tendency to react with the non-ironic surfactants and thus their activity is reduced to 50-80%.
The preservative efficacy should be judged in the final product since incompatilities may exit
Tween 80 is incompatable with p-hydroxy benzoate and all quaternary ammonium compounds. Substances interacted/inactivated with non-ionic surfactants.

Benzoic acid, gallate, all p-hydroxy benoates, p-chloro benzoic acid, Na benzoate, sorbic acid, and usnic acid.

The preservatives were sorted according to their chemical reactions. When a preseravative belongs to several categories, however the depends on the specifict of the reactions.

Class Ac: acids and eters
Class l : Halogenated compounds
Class Ph: Phenols
Class F: Geneeally prerervaivesed

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