Spectrophotometric Determination Methyldopa and Salbutamol by Oxidative Coupling, Cloud Point and Flow Injection in Pharmaceutical Formulations

Abstract

TThree methods study in this research simple, sensitive, an expensive and rapid Oxidative Coupling reaction, Cloud Point Extraction and Flow Injection spectrophotometric methods for determination Methyldopa and Salbutamol, the first method oxidative coupling reaction between the Methyldopa and thiosemicarbazide in presence of ferric nitrate anhydrous to yield dark green colored product that have absorbance at λ max 460 nm. Salbutamol coupling reaction with 4-nitrophenyl hydrazine in presence the potassium Iodide and sodium hydroxide to product the violet colored has absorbance at λ max 530 nm. Beer’s law is obeyed from (1-50) µg/ mL with sandall’s sensitivity (0.039,0.073), correlation coefficient (0.9998) and molar absorptivity (0.536×104,0.327×104) for Methyldopa and Salbutamol respectively. The secondly method to estimation the trace amount of phenolic drugs that product from the oxidative coupling reaction it is cloud point extraction, cloud point extraction enables the drugs to be precisely estimated under the optimal experimental conditions, the maximum absorption at λ max (470,535) nm respectively. The concentration was range (0.25-6) µg/mL, molar absorptivity 0.510×105 ,0.483×105 and enrichment factor (9.51,14.72) respectively for Methyldopa and Salbutamol.Flow injection analysis is simple method to determination the phenolic is based on the measurement of absorption signal for product resulting from oxidative coupling reaction , study all experimental parameters chemical and physical to development and stability the colored of product .Total flow injection of 1.5mL/min was pumped and active material was detect at λ max (460,530)nm respectively for Methyldopa and Salbutamol . In this the proposed methods were suxciffuly, applied to the determination Methyldopa and Salbutamol in pharmaceutical preparation.

Application of Cloud Point Method for Spectrophotometric Determination of Salbutamol Sulphate and Methyldopa

“…The present spectrophotometric method has been compared with other spectrophotometric methods for determination of salbutamol and methyldopa. These methods are depended on the reduction of gold to gold nanoparticles in the presence of SDS surfactant for determination of salbutamol [29], 2,6-dichloroquinone-4-chlorimide (DCQ) in the medium of acetate buffer as coupling reagent for determination of methyldopa [30], and application of cloud point extraction in oxidative coupling reaction for determination of methyldopa and salbutamol using thiosemicarbazide and 4-nitrophenyl hydrazine respectively [15]. As seen in Table 4, the suggested method is more sensitive, accurate and precise than other methods.…”

“…For the determination of salbutamol sulphate and methyldopa, different analytical techniques have been proposed, like spectrophotometric [4][5][6][7][8][9][10][11][12][13][14][15], chromatographic [16][17][18][19], voltammetric [20][21], potentiometric [22], flow injection [23] and kinetic [24] methods. Our determination of salbutamol sulphate and methyldopa spectrophotometrically is actually new, simple, and sensitive.…”

A novel sensitive colorimetric determination of catecholamine drug in dosage form via oxidative coupling reaction with MBTH and potassium ferricyanide

“…Many spectrophotometric procedures have been proposed for the estimation of MD in pharmaceutical preparations including difference UV-spectrophotometric assay in the presence of germanium dioxide at 292 nm [22], Flowinjection spectrophotometry [23][24][25][26], fluorimetry [27,28], kinetic spectrophotometry [29][30][31] and extractive spectrophotometry [32,33]. Moreover, the colorimetric method was the most widespread for estimation of MD in dosage form using I2 solution with acetate buffer of pH 4.7 [4], 2-aminothiazole in alkaline medium [25], thiosemicarbazide in presence of ferric nitrate [26], NH4VO3 in the presence H3PO4 [34], (NH4)6Mo7O24.4H2O solution in H2SO4 [35], Fe(III)-ophenanthroline [36], barbituric acid [37], isoniazid in presence of Nbromosuccinamide [38], diazotised sulphanilamide in the presence of molybdate [39], periodate in H2SO4 and determination of unreacted periodate by adding methylene blue and KI [40], iron (III) in the presence of 1,10phenanthroline and 2,2'-bipyridyl [41], p-nitroaniline in the presence of molybdate ions in acidic medium [42], Ce(IV) nitrate solution in H2SO4 [43], bromothymol blue in alkaline medium [44], sodium nitrite in an acid medium and further reacting the resultant nitroso derivative with sodium hydroxide [45], 2,2-diphenyil-picrylhydrazyl [46], 2,6dichloroquinone-4-chlorimide in acetate buffer and in water and ethanol solvents [47] and p-phenylenediamine in phosphate buffer at pH 7.4 [48]. 3-methylbenzothiazolin-2one hydrazone hydrochloride (MBTH) was used with (NH4)2SO4.Ce(SO4)2 in acetone or with K2Cr2O7 in methanol medium to determine MD.…”

Spectrophotometric Determination of Sulfadoxine Drug use Cloud point and Flow injection Methods in Pharmaceutical Formulations

“…However, many of these methods suffer from one or more disadvantages such as critical optimum conditions, heating, and extraction using an organic solvent, narrow linear dynamic range, poor selectivity and low sensitivity [18]. Flow injection is the best technique characterized as easy, inexpensive, quick and selective drug estimation [19], and the flow injection analysis (FIA) method has many interests, such as increasing sample throughput, low reagent use, reducing waste generation, and inexpensive equipment [20,21]. New methods for estimating sulfadoxine in conventional medicines are used in this work, based on eco-friendly and cheap methods that deliver quick, automated, reliable , accurate results that are applicable for use and do not require high work experience.…”