Spectrophotometric flow injection procedure to indirect determination of paracetamol in pharmaceutical formulations using o-tolidine as reagent

Abstract

IntroductionParacetamol (4-acetoaminophen) has mild analgesic and antipyretic properties and is, along with acetylsalicylic acid, one of the most popular analgesic agents. The administration of this drug with caffeine yields analgesic effects significantly greater than that of paracetamol alone [1,2].Several methods have been employed for the spectrophotometric determination of this drug in combined dosage forms [3][4][5][6][7]. Chromatographic methods have been proposed for the simultaneous determination of paracetamol and other active principles [8][9][10], Fluorescence spectroscopy methods were also described [11,12], however those methods are time-consuming and use expensive equipments. Electroanalytical methods were proposed to paracetamol determination in pharmaceutical formulations using carbon paste electrode [13][14][15].Flow injection systems are useful tools for the automation, miniaturization and simplification of analytical processes. These procedures permit obtain results faster and accurate than batch procedures [16].Flow injection spectrophotometric systems with spectrophotometric detection were described using nitrite as reactant [17][18][19]. Other spectrophotometric flow injection methods based on reaction of paracetamol to produce a indophenol dye [20][21][22][23][24] and systems with solid phase UV spectrophotometric detection [25][26][27][28] have been described for paracetamol determination in pharmaceutical formulations. Flow procedures with chemiluminescence detection were described using luminol based reaction [29,30] Abstract: A spectrophotometric flow injection method for the determination of paracetamol in pharmaceutical formulations is proposed. The procedure was based on the oxidation of paracetamol by sodium hypochloride and the determination of the excess of this oxidant using o-tolidine dichloride as chromogenic reagent at 430 nm. The analytical curve was linear in the paracetamol concentration range from 8.50 x 10 -6 to 2.51 x 10 -4 mol L -1 with a detection limit of 5.0 x 10 -6 mol L -1 . The relative standard deviation was smaller than 1.2% for 1.20 x 10 -4 mol L -1 paracetamol solution (n = 10). The results obtained for paracetamol in pharmaceutical formulations using the proposed flow injection method and those obtained using a USP Pharmacopoeia method are in agreement at the 95% confidence level.

Determination of Paracetamol and Kinetic Parameters Using Nickel Hexacyanoferrate Modified Carbon Paste Electrode.

“…The methods are titrimetric analysis [5], Spectrofluorimetry [6], Chronoamperometry [7], Colorimetry [8], Amperometry [9], Chemiluminescence [10], Spectrophotometry (Uv-spectrophotometry) [11], Derivative Spectrophotometry [12], various kinds of High Performance Liquid Chromatography [13], Quantitative Thin-layer Chromatography (TLC), [14]. Flow Injection Analysis (FIA) (using different methods of detection), [15]. Gas Chromatography [16], Capillary Electrophoresis conducted in single component as well as multi-component systems have to be mentioned [17].…”

Simple and Improved Visible Spectrophotometric Method for Determination of Paracetamol Using Sodium Nitroprusside Chromogenic Reagent

“…Literature survey revealed many methods with different analytical techniques for individual or simultaneous determination of PCT in different sample types. The technique includes voltammetry [9][10][11][12][13][14] , CE [15][16] , TLC [17][18] , HPLC [19][20][21] , RP-HPLC [22][23] , LC-MS 24 , LC-MS-MS [25][26][27][28] , GC 29 , FTIR 30 , spectrofluorimetry [31][32][33][34] , kinetic spectrophotometry [35][36] , derivative spectrophotometry [37][38] , indirect spectrophotometry 39 , direct spectrophotometry [40][41][42][43][44][45] etc. The techniques other than spectrophotometry require lengthy procedures, highly sophisticated analytical instruments and some amount of the organic solvents contributing towards high cost of the analysis.…”

A multicommuted flow analysis method for the photometric determination of amoxicillin in pharmaceutical formulations using a diazo coupling reaction

“…5 A comprehensive review of the literature indicates a number of analytical methods for the determination of amoxicillin. These include methods based on spectrophotometry, [6][7][8][9][10][11][12] chemiluminescence, 3,13 fluorometry, 14,15 polarography, 16 and mass spectrometry. 17,18 Electrophoresis capilar, 5,19 and HPLC 20,21 are included when separation techniques are used.…”