how do we consider equipment surface area for cleaning validation?
Please consider all the equipment and its different parts used to manufacture the batch of one product. Calculate inner surface area of each equipment and its different parts which are coming in direct contact with the product during manufacturing. Similarly consider vessles. containers, storage tanks, Spatulas, and other accessories used. This is calculated by the Engineering deparment persons using mathamatical / geometrical formulae. Add up all the surface areas to get total surface area which is exposed to the product.
Similarly calculate surface areas for other products.