In scientific and analytical research, Ultraviolet-visible spectroscopy, Fourier Transform Infrared spectroscopy, and Nuclear Magnetic Resonance spectroscopy have widely been used to analyze and characterize various substances. Ultraviolet, infrared, and Nuclear Magnetic Resonance spectroscopy were studied for diastereoisotopic protons of dorzolamide, which is used to treat glaucoma and ocular hypertension. Methanol was used as a solvent in Ultraviolet and we obtained three wavelengths: 203 nm, 253 nm, and 257 nm, where Ultraviolet spectroscopy was employed for stability testing of pharmaceuticals. By analyzing the Fourier Transform Infrared spectrum, we also can determine the presence or absence of specific functional groups in a compound, helping to identify the compound or confirm its structure in analyzing the Nuclear Magnetic Resonance spectrum. It can determine the types and numbers of hydrogen (proton) and carbon atoms in a molecule and their chemical environment, which helps elucidate the molecular structure.