Page 74 - Quality control of pharmaceuticals (07-PA 704)

particulary susceptible to oxidation and have to be formed at acidic pH. All of these
compounds are white crystalline solids that darken on exposure to air.
Adrenaline forms the red coloured compound adrenochrome on oxidation which can
further polymerise to give black compounds similar in structure to melanin, the
natural skin pigment. Injections of adrenaline that develop a pink colour, or that
contain crystals of black compound, should not be used for this reason. Adrenaline
for injection it formulated as the acid tartrate, which, in aqueous solution, gives a pH
of approximately 3. It is called the acid tartrate since only one carboxylic acid group
of tartrate acid is used up in salt formulation with adrenaline. This leaves the
remaining carboxylic group to function as an acid.

Stability- Indicating Method (SIM)
The quality of analytical data generated on stability samples is essential to the
successful completion of stability, studies. Using the broad definition, SIM is any
method that can reliably detect a specific physic-chemical change of the drug
material or product.
Therefore, SIM is an analytical method capable for:

1. Determining the drug substance accurately
2. Detecting degradation products
3. Discriminating between the active ingredients and the degradation products:

a) Under defined storage conditions
b) During a period for stability evaluation