Determination and validation of pKa value of atropine sulfate using spectrophotometry

The ionization state (pKa) of a compound influences its absorption, distribution, metabolism and excretion. Therefore, proper knowledge of the pKa is crucial in understanding the behavior of a compound behavior inside the body. In this research paper, we validate the pKa of muscarinic acetylcholine receptor antagonist atropine sulfate using Uv-Vis spectroscopy, to validate the use of this method and to re-evaluate the of atropine sulfate. The pKa value from absorption measurements is first estimated using 3^rd degree polynomial and then precisely calculated according to the Albert-Sergeant method. We established that the pKa value of Atropine sulfate is 9.94±0.050 which is comparable to the values present in the literature.