Determination of N-Acetylcysteine in Pure and Drug Formulations Using Inhibitory Kinetic Approach

• Published in: Pharmaceutical chemistry journal 2023-08, Vol.57 (5), p.756-762
• Main Authors: Srivastava, Abhishek, Srivastava, Neetu, Srivastava, Anupam, Yaseen, Bushra, Gangwar, Chinky, Naik, Radhey Mohan
• Format: Article
• Language: English
• Subjects: Acetylcysteine; Drugs; Medicine; Methods; Organic Chemistry; Pharmacology/Toxicology; Pharmacy
• ISSN: 0091-150X; 1573-9031
• DOI: 10.1007/s11094-023-02949-3

A simple, reproducible, and swift inhibitory kinetic approach for the N-acetylcysteine (NAC) determination has been developed and linked to NAC quantification in drug formulations. The method is based on the inhibitory feature of N-acetylcysteine. NAC forms a stable complex with Hg 2+ and reduces the actual Hg 2+ concentration and ultimately the rate of reaction between N-R-salt and [Ru(CN) 6 ] 4- catalyzed by Hg 2+ . Under the optimized experimental conditions with Temp = 45.0 ± 0.1°C, I = 0.05 mole dm -3 (KNO 3 ), [N-R-salt] = 5.5 × 10 -4 mole dm -3 [Hg +2 ] = 8.0 × 10 -5 mole dm -3 , pH = 6.0 ± 0.02, and [Ru(CN) 6 4- ] = 5.25× 10 -5 mole dm -3 , fixed time of 7 and 12 min was selected to compute the absorbance at 525 nm corresponding to the ultimate reaction product [Ru(CN) 5 N-R-salt] 3- . The inhibitory action of NAC toward cyanide imitation from [Ru(CN) 6 ] 4- by N-R-salt, catalyzed by Hg 2+ , has been demonstrated using a redesigned mechanistic scheme. With the proposed kinetic spectrophotometric method the micro-level quantification of NAC in distinct water samples can be done down to 1.25 × 10 -6 mole dm -3 . The developed procedure is highly reproducible and can be efficiently used to quantitatively estimate the NAC in the drug samples with high accuracy. The general additives present in drugs do not substantially interfere in the determination of NAC even up to 1000 times with [NAC].