Different Spectrophotometric and TLC-Densitometric Methods for Determination of Mesalazine in Presence of Its Two Toxic Impurities

Abstract

Two selective spectrophotometric and TLC-densitometric methods were developed for determination of mesalazine (ME) and its two toxic impurities, 4-amino phenol (4AP) and salicylic acid (SA) without preliminary separation. The proposed methods are: ratio difference in the subtracted spectra (RDSS) {Method 1}, area under the curve (AUC) {Method 2} and TLC-densitometric {Method 3}. In method {1} combination of measuring the amplitude of the constant at 350 nm (using standard spectrum of 10 µg/mL ME as a divisor) and ratio difference in the subtracted ratio spectrum for determination of 4AP and SA using the ratio difference at 221.4 and 242.2 nm, 230 and 241.2 nm, respectively. In method {2} ME was determined by direct measuring the AUC in the wavelength range of 350-370 nm while the impurities could be determined by dividing their spectra by standard spectrum of 10 µg/mL ME then interference from ME was eliminated by subtracting the amplitude of the constant at 350 nm then multiplying by the divisor. AUC in the range of 220-230 and 235-245 nm was used for measuring concentrations of 4AP and SA. On the other hand, the third method {3} is TLC-densitometric method at which chromatographic separation was achieved using ethyl acetate-methanol-triethylamine (8.5 : 2 : 0.7, v/v/v) as a developing system with UV scanning at 230 nm. The validation of the proposed methods was performed according to International Conference on Harmonization (ICH) guidelines. No significant difference was found when these methods were compared to the reported one.

Green Spectrophotometric Method for Determination of Mesalazine Drug by Oxidative Coupling Reaction with Phenoxazine

“…1B) [14] is used to treat ulcerative colitis and Crohn's disease [15] collectively referred to as inflammatory bowel diseases [9]. According to the reviewed literature, several methods have been reported for MZN determination, including spectrophotometric [16][17][18][19][20], electrical [21][22][23] and HPLC methods [24,25]. Our proposed method is based on the oxidative coupling reaction of MZN with PXN in an acidic medium in the presence of potassium iodate as an oxidizing agent.…”

Development and Validation of UV Spectrophotometric Method of Mesalamine Using Hydrotropic Solubilizing Agents

“…To date, there are various methods to detect Mesalamine like RP-UHPLC method (Balaji and Shivashankar, 2017), Spectroscopic methods (Prajapati et al, 2016), Vireodt's method (Jain et al, 2012), TLC Densitometric methods (Morcoss et al, 2016). Hydrotropic solubilizing agents have not been studied using the UV-Spectrophotometric method to unmask Mesalamine in pharmaceutical formulations.…”