Shelf life Stability: is the period of time, from the date of manufacture, that a drug product is expected to remain within its approved product specification while stored under defined conditions. Shelf life is typically expressed in units of months, i.e. 24 months, 36 months, to a maximum of 60 months.
There are three basic forms of Stability tests:
1-Physical and chemical integrity: These evaluate the color, odor or fragrance, pH value, viscosity, texture, flow and emulsion stability, or signs of separation.
2-Microbio­logical stability: These evaluate the degree of contamination with bacteria, mold and/or yeast.
3-Packaging stability: These evaluate the effect of packaging on the contained product.