The method is semi-quantitative and the quantitative method is back titration in which an additional step of titration of unutilized NaOH with HCl is to be included. It is possible that due to incomplete hydrolysis the theoretical 2:1 molar ratio of NaOH: Acetylsalicylic acid is not attained. Acetylsalicylic acid is not fairly water-soluble and as titration proceeds, the solution becomes aqueous which brings out a possibility of precipitation resulting in turbidity that causes errors in endpoint determination. Placebo may contain substances like starch and other adulterated powders interfering with solubility and titration. Sometimes aspirin intrigue may also contain sodium acetate salt a reactant used in the synthesis of acetylsalicylic acid. This may self take part in titration as it is an acid and can give misjudgment about the quantity of acetylsalicylic acid.
It is concluded that there is the negligible presence of the effective drug acetylsalicylic acid in placebo internet aspirin (only 1.4%) as compared to what is found in the control Bayer’s aspirin.
