Validated Spectrophotometric Methods for the Determination of Oxybuprocaine Hydrochloride

Simple, rapid, accurate and reliable spectrophotometric methods were developed and validated for determination of Oxybuprocaine hydrochloride (OXY) in pure form and in pharmaceutical preparation. The methods depend on charge transfer reaction of OXY as n-electron donor with p-chloranilic acid (p-CA), 2, 3 – dichloro 5, 6 – dicyano 1, 4 benzoquinone (DDQ) and iodine as π and σ acceptors, respectively. These reactions were studied under various conditions and the optimum parameters were selected. Under the optimum reaction conditions, linear relationships with good correlation coefficients (0.9996, 0.9997, and 0.9998) were found between absorbance of the formed complexes and concentrations of OXY in the range of 20.0 - 220.0 μg/mL, 10.0-80.0 μg/mL and 4.0-44.0 μg/mL for (p-CA), DDQ and iodine methods, respectively. The methods were successfully applied for the determination of OXY in pure form and in dosage form. Job’s method was applied to determine the stoichiometry of the reactions. No significant difference was found at p = 0.05 when the obtained results of the proposed methods were statistically compared with those obtained by an official method

Titanium nanoparticles (TiO2)/graphene oxide nanosheets (GO): an electrochemical sensing platform for the sensitive and simultaneous determination of benzocaine in the presence of antipyrine.

An effective electrochemical sensing platform for the simultaneous determination of benzocaine (BEN) and antipyrine (ANT) based upon titanium dioxide nanoparticle (TiO2)/graphene oxide nanosheet (GO) bulk modified carbon paste electrodes (TiO2-GO/CPE) is reported. The TiO2-GO/CPE electrochemical sensing platform is found to exhibit linear ranges from 1.0 × 10-6 to 1.0 × 10-4 M and 1.2 × 10-8 to 8.0 × 10-5 M for BEN and ANT, respectively. The TiO2-GO/CPE sensor is explored towards the analysis of BEN and ANT in oral fluid (saliva) and pharmaceutical products. The synergy between the graphene oxide nanosheets and titanium dioxide nanoparticles results in a dramatic enhancement in the sensitivity of the sensor through a combination of increased surface area and improved electron transfer kinetics compared to other electrode alternatives. The fabricated TiO2-GO/CPE exhibits high sensitivity and good stability towards the sensing of BEN and ANT and has the potential to be utilised as a clinical assay and QA in pharmaceutical products

Simple spectrophotometric methods for the simultaneous determination of antipyrine and benzocaine

Antipyrine and benzocaine are formulated together for the treatment of ear inflammation and to relieve pain. Four spectrophotometric methods were developed for the simultaneous determination of antipyrine (AN) and benzocaine (BE) in their combined dosage form. Method A depends on applying dual wavelength method where antipyrine was determined by measuring the absorbance at 254.1 and 309.1 nm (corresponding to zero difference of benzocaine), while the absorbance difference at 230.1 and 263.5 nm (corresponding to zero difference of antipyrine) was selected for benzocaine determination in the laboratory prepared spectrum. Method B depends on measuring the peak amplitude of first derivative at 305 nm for calculating benzocaine concentration then the total concentration of both drugs was determined using isoabsorptive point at 257.4 nm (antipyrine concentration was then calculated by subtraction). Method C is based on measuring the peak difference of the ratio spectra at Δp (239.1–285 nm) and Δp (301.4–250 nm) for the determination of antipyrine and benzocaine, respectively. Method D depends on measuring peak to peak amplitude of the first derivative of ratio spectra at (234.5 + 244.2 nm) and peak amplitude at 295.5 nm for the determination of antipyrine and benzocaine, respectively. The proposed methods were validated and applied for the analysis of antipyrine and benzocaine in their laboratory prepared mixtures and pharmaceutical formulation. Statistical comparison between the results of the proposed methods and those of the reported methods showed no significant difference

Chromatographic methods for the simultaneous determination of binary mixture of Saxagliptin HCl and Metformin HCl

Two chromatographic methods were suggested for the simultaneous determination of a binary mixture containing Saxagliptin HCl (SAG) and Metformin HCl (MET). First method was RP-HPLC method. Chromatographic separation was done on Kinetex⢠columnâC18 (4.6 Ã 150 mm, 2.6 µm) using mobile phase consisted of acetonitrile:phosphate buffer pH = 4.5 ± 0.1 adjusted with orthophosphoric acid (13:87, v/v). Isocratic elution at a flow rate 1.5 mL/min and UV detection at 220.0 nm was performed. Second method was spectro-densitometric method. Chromatographic separation was done on precoated silica gel aluminium plates 60 F254 as a stationary phase and developing system consisting of chloroform:methanol:formic acid (80:20:0.3, by volume). The density of the separated bands was measured by UV detector at 210.0 nm. The proposed methods were validated as per the ICH guidelines parameters like Linearity, precision, accuracy, selectivity, limit of detection and limit of quantitation. Statistical comparison was done between the obtained results and those obtained by the reported methods, showing no significant difference with respect to accuracy and precision. Keywords: Saxagliptin HCl, Metformin HCl, RP-HPLC, TL

Validated chromatographic methods for the simultaneous determination of Mometasone furoate and Formoterol fumarate dihydrate in a combined dosage form

Two chromatographic methods were developed and validated for the simultaneous determination of Mometasone furoate (MO) and Formoterol fumarate dihydrate (FOR). Combination of MO and FOR is used for the treatment of asthma in patients suffering from reversible obstructive airway disease. The first chromatographic method was based on using aluminum TLC plates pre-coated with silica gel GF254 as the stationary phase and chloroform:ethyl acetate:methanol:toluene:formic acid (5:2:2:2:0.1, by volume) as the mobile phase followed by densitometric measurement of the separated bands at 233 nm. The second method is a high performance liquid chromatographic method for the separation and determination of MO and FOR using reversed phase C18 column with isocratic elution. The mobile phase composed of methanol: 0.5% ammonium acetate pH adjusted with acetic acid (80:20, v/v) at a flow rate of 1.0 mL/min. Quantitation was achieved with UV detection at 220 nm. The specificity of the developed methods was investigated by analyzing the pharmaceutical dosage form. The validity of the proposed methods was assessed using the standard addition technique. The obtained results were statistically compared with those obtained by the reported methods, showing no significant difference with respect to accuracy and precision at p = 0.05

Novel stability indicating methods for the determination of certain synthetic estrogen level modifiers

Tamoxifen citrate (TC) and raloxifene hydrochloride (RH) are two selective estrogen receptor modifiers. TC is usually used in the treatment of breast cancer while RH is used in the treatment of osteoporosis. Two stability indicating methods, namely, first derivative of ratio spectra (1DD) and TLC-densitometric method are used for the determination of TC in the presence of its photodegradants and RH in the presence of its oxidative degradants. For the first derivative of ratio spectra method, TC was quantitatively measured at 263 nm and 298.2 nm in a concentration range of 10–60 μg/mL while RH was determined at 267.6 nm in a concentration range of 2–18 μg/mL. In the spectro-densitometric method, TC was separated from its photodegradants using a developing system consisting of acetonitrile: 33% ammonia solution (10: 0.1, v/v) in a concentration range of 6–20 μg/band while RH was separated from its oxidative degradants using ethyl acetate: methanol: 33% ammonia solution (7: 3: 0.1, by volume) as a developing system in a concentration range of 3–11 μg/band. The two methods were successfully applied for the stability indicating the determination of the two drugs in a pure powdered form and a pharmaceutical dosage form and showing good recoveries. Statistical comparison between the results obtained by applying the proposed methods and the official method or the reported method for TC and RH, respectively was done and no significant difference was found at p = 0.05

Spectrophotometric Methods for Simultaneous Determination of Oxytetracycline HCl and Flunixin Meglumine in Their Veterinary Pharmaceutical Formulation

Four precise, accurate, selective, and sensitive UV-spectrophotometric methods were developed and validated for the simultaneous determination of a binary mixture of Oxytetracycline HCl (OXY) and Flunixin Meglumine (FLU). The first method, dual wavelength (DW), depends on measuring the difference in absorbance (ΔA 273.4–327 nm) for the determination of OXY where FLU is zero while FLU is determined at ΔA 251.7–275.7 nm. The second method, first-derivative spectrophotometric method (1D), depends on measuring the peak amplitude of the first derivative selectively at 377 and 266.7 nm for the determination of OXY and FLU, respectively. The third method, ratio difference method, depends on the difference in amplitudes of the ratio spectra at ΔP 286.5–324.8 nm and ΔP 249.6–286.3 nm for the determination of OXY and FLU, respectively. The fourth method, first derivative of ratio spectra method (1DD), depends on measuring the amplitude peak to peak of the first derivative of ratio spectra at 296.7 to 369 nm and 259.1 to 304.7 nm for the determination of OXY and FLU, respectively. Different factors affecting the applied spectrophotometric methods were studied. The proposed methods were validated according to ICH guidelines. Satisfactory results were obtained for determination of both drugs in laboratory prepared mixture and pharmaceutical dosage form. The developed methods are compared favourably with the official ones