Spectrophotometric Determination of Some Tranquillizers and Antidepressants Using 2,3-Dichloro 5,6-Dicyano-p-Benzoquinone

Abstract

A simple and sensitive spectrophotometric method is described for the assay of some tranquillizers and antidepressants, namely, chlorpromazine, imipramine, amitriptyline and chlorprothexine. The method was based on the interaction of these drugs as n-electron donors with 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) as λ -acceptor to give a highly coloured radical anion which exhibits maximum absorption at 460 nm. The radical anion was proved by electron spin resonance measurements. The proposed method has been successfully applied for the determination of the examined drugs in tablets. The assay results were in accord with the pharmacopoeial results.     

TLC Determination of Amitriptyline HCl,Trifluoperazine HCl,Risperidone and Alprazolam in Pharmaceutical Products

A simple, sensitive, and precise thin layer chromatographic (TLC) method for simultaneous analysis of psychopharmacological drugs like amitriptyline HCl, trifluoperazine HCl, risperidone and alprazolam in their single dosage forms has been developed, validated, and used for determination of the compounds in commercial pharmaceutical products. The TLC separation was carried out on Merck TLC aluminium sheets of silica gel 60 F254 using carbon tetrachloride:acetone:triethylamine (8:2:0.3, v/v/v), as mobile phase. Densitometric measurements of their spots were achieved at 250 nm over the concentration range for amitriptyline HCl (50–1,200 ng spot⁻¹), trifluoperazine HCl (50–1,200 ng spot⁻¹), risperidone (100–2,400 ng spot⁻¹) and alprazolam (25–600 ng spot⁻¹). Limit of detection (LOD) for amitriptyline HCl (20 ng spot⁻¹), trifluoperazine HCl (20 ng spot⁻¹), risperidone (40 ng spot⁻¹) and alprazolam (5 ng spot⁻¹) was obtained. The study showed that TLC was sensitive and selective for determination of amitriptyline HCl, trifluoperazine HCl, risperidone and alprazolam using a single mobile phase. This proposed method is able for simultaneous determination of psychopharmacological drugs and also applicable for analysis of pharmaceutical formulations.

     

Reversed Phase High - Performance Liquid Chromatographic Analysis of Tricyclic Antidepressants in Plasma

Abstract

A reversed phase HPLC procedure is described for measuring the plasma concentration of four commonly used tricyclic anti-depressants (TCA): amitriptyline, desipramine, imipramine and nortriptyline in the range of 25 to 800ng per ml. The procedure involves rapid extraction, and HPLC analysis using a μBondapak C-18 column at 50°C, and a 254nm detector. Coefficients of variation are less than 5% for within run, and 7% for day-to-day experiments. Detection limits are: desipramine -0.5ng, nortriptyline or imipramine -0.6ng, and amitriptyline -0.7ng. Propoxyphene interferes with amitriptyline while chlorpromazine interferes with clomipramine. The procedure is easily adapted for clinical drug monitoring of TCA.     

The High-Pressure Liquid Chromatographic Determination of Chlordiazepoxide and Its N-Demethyl Metabolite in Mouse Brain

Abstract

This report presents a simple and accurate method for the analyses of chlordiazepoxide and its N-demethyl metabolite in small tissue samples such as mouse brains. The procedure involves the addition of diazepam as the internal standard, homogenization of the mixture with 0.01 N NaOH, and extraction with heptane containing 1.5% (v/v) iso-amyl alcohol. After evaporation of the organic solvent, the residue is dissolved in methanol and the compounds separated by reverse phase high pressure liquid chromatography with 66% (v/v) methanol in water as eluant in isocratic conditions. The analysis is linear for concentrations ranging from 0.5 to 50 ng/mg brain for chlordiazepoxide and the metabolite. The method was applied to the study of the distribution of chlordiazepoxide and the N-demethyl metabolite to the brain of mice receiving intraperitoneally 10 mg/kg chlordiazepoxide HCl.     

Application of Derivative and Ratio Spectra Derivative Spectrophotometry for the Determination of Pseudoephedrine Hydrochloride and Acrivastine in Capsules

Abstract

Two new spectrophotometric methods are used for the determination of acrivastine and pseudoephedrine hydochloride in their mixture without previous chemical separation. In the first, second derivative spectrophotometry, the measurements are made at 288.0 nm for acrivastine and at 270.2 nm for pseudoephedrine hydrochloride in the second derivative spectra of their solution in 0.1M NaOH. In the second, ratio spectra derivative spectrophotometry, the amplitudes are measured at 276.0 nm and 298.5 nm corresponding to two maximums for acrivastine, and at 252.6 nm and 268.3 nm corresponding to a maximum and a minumum, respectively, for pseudoephedrine hydrochloride in first derivative of their ratio spectra plotted by using of their solutions as divisor. The methods were successfully applied for the determination of these drugs in a commercial pharmaceutical formulation capsule.     

Development and Validation of High Performance Liquid Chromatographic and UV-Derivative Spectrophotometric Methods for the Determination of Sotalol Hydrochloride in Tablets

Abstract

High performance liquid chromatographic (HPLC) and UV derivative spectrophotometric (UVDS) methods were developed and validated for the quantitative determination of sotalol hydrochloride in tablets. The HPLC method was performed on a C18 column with fluorescence detection. The excitation and emission wavelengths were 235 and 310 nm, respectively. The mobile phase was composed of acetonitrile-water containing 0.1% trietylamine (7:93 v/v) and pH adjusted to 4.6 with formic acid. The UVDS method was performed taking a signal at 239.1 nm in the first derivative. The correlation coefficients (r) obtained were 0.9998 and 0.9997 for HPLC and UVDS methods, respectively. The proposed methods are simple and adaptable to routine analysis.     

Flow Injection Analysis of Carboxylic Acid Drugs Using Cationic Dyes and On-Line Ion-Pair Extraction

Abstract

A flow injection system containing an on-line ion-pair extractor has been designed for the analysis of carboxylic acid drugs using either spectrophotometric detection with gentian violet as counterion or fluorescence detection with acridine orange. Salicylic acid, valproic acid, and ibuprofen were selected as model drugs. A mobile phase of 90:10 aqueous pH 7 phosphate buffer-absolute methanol was pumped through the system at 1 ml/min. A chloroform solution of the cationic dye was pumped into the mobile phase at 1.25 ml/min and the chloroform layer containing the dye-drug ion-pair separated prior to detection. Peak height and absorbance were linear for salicylic acid, valproic acid, and ibuprofen in the 0.5–10, 5–50, and 1–10 μg/ml ranges, respectively. Peak height and fluorescence were linear for salicylic acid, valproic acid, and ibuprofen in the 0.13–5, 2.5–50, and 0.5–20 μg/ml ranges, respectively. Accuracy and precision for the spectrophotometric assays were in the 2–6% and 3.3–6.6% ranges, respectively, and in the 0.3–4% and 1.3–5.4% ranges, respectively, for the fluorescence assays. Peak height and absorbance were also shown to be linear in the 16–500 μg/ml range for prostaglandin PGF_2α with accuracy and precision of 1–3% and 5–6%, respectively, for spiked samples. Commercial dosage forms containing valproic acid and ibuprofen were assayed by the spectrophotometric assay and found to be within acceptable USP limits. Spiked ibuprofen samples at the 5 and 10 μg/ml level were assayed using an octadecylsilane column inserted into the flow injection system. One to two percent accuracy and 2.5–5% precision were obtained for the drug using the FIA-column system.     

Simple Spectrophotometric Determination of Total Carbonate by Re-Extraction Via Ligand Exchange Using Chloroform Solutions of Uranyl Quinolin-8-Olate

Abstract

A method based on the decoloration of dilute chloroform solutions of ura nyl quinolin-8-olate by shaking with aqueous solution of anions is proposed for the spectrophotometric determination of carbonate. The effects of several variables on the decoloration (pH, shaking time, volume ratio, etc.) were established. The spectral stability of an organic solution of the metal chelate is increased with an excess of quinolin-8-ol in the organic phase, and it avoids its stripping with water. The decoloration of chloroformic solutions varies linearly with the carbonate concentration between 10 and 50 μg.ml^?1 in the aqueous phase (apparent molar absorptivity is found to be 2.03×10³ l.mol^?1 .cm^?1 at 390 nm). Interferences of many foreign ions (cations and anions) are also established. The method is relatively free from anion interferences.     

A Rapid and Inexpensive Thin Layer Chromatographic Method for Quantitative Analysis of Bleomycin Complex

Abstract

A densitometric and a spectrophotometric method for rapid but accurate determination of different components of bleomycin injections has been described. The bleomycin components were separated by reversed phase thin layer chromatography on silanized silicagel plates using a mixture of aqueous ammonium nitrate (2.5%) : methanol :: 7 : 3 (v/v) as mobile phase. Assay was done at the absorption maxima of the components (291 nm) by in situ densitometry or by spectroscopy after extracting the drugs from the adsorbent with the mobile phase. Results obtained by both the methods agreed well with each other and with those obtained by an official HPLC method. The densitometric method described was highly suitable for routine quality control of bleomycines as a large number of samples could be analysed within a short time (68 samples/analyst/day).     

Extraction and Spectrophotometric Determination of Zirconium(IV)

Abstract

A sensitive and selective method for the extraction and spectrophotometric determination of Zr(IV) with N-p-chlorophenyl-3,4-,5-trimethoxycinnamohydroxamic acid (PTCHA) has been developed. The binary complex of Zr(IV)-PTCHA is extracted from 2–6 M HCl into chloroform, having a maximum absorbance at 385 nm; molar absorptivity 2.1 × 10⁴ 1 mol^?1 cm^?1. A ternary complex with xylenol orange (Zr-PTCHA-XO) have been studied in chloroform-ethanol media, which absorbs at 540 nm; molar absorptivity 4.3 × 10⁴ 1 mol^?1 cm^?1. The present method is applied for the analysis of zirconium in standard samples.     

Quantitative Determination of Nadolol in Tablets by High‐Performance Liquid Chromatography and UV‐Derivative Spectrophotometry

Abstract

High‐performance liquid chromatographic (HPLC) and UV derivative spectrophotometric (UVDS) methods were developed and validated for the quantitative determination of nadolol in tablets. The HPLC method was performed on a C18 column with fluorescence detection. The excitation and emission wavelengths were 230 and 300 nm, respectively. A mobile phase composed by acetonitrile‐water containing 0.1% triethylamine (15∶85 v/v) and pH adjusted to 4.6 with formic acid was used. The UVDS method was performed taken a signal at 279.5 nm. The correlation coefficient (r) obtained for both methods was 0.9999. The proposed methods are simple, precise, accurate, and can be used in routine analysis.     

Simultaneous Determination of Cilazapril and Hydrochlorothiazide in Tablets by Spectrophotometric Methods

Abstract

In this study, two new spectrophotometric methods were used for the simultaneous determination of cilazapril and hydrochlorothiazide in their binary mixture. In the first method, derivative spectrophotometry, dA/dδ values were measured at 242.8 nm and 282.8 nm for cilazapril and hydrochlorothiazide, respectively, in the first derivative spectra of their combination. The relative standard deviation of the method was found to be 0.77% for cilazapril and 0.24% for hydrochlorothiazide. In the second, the absorbancy ratio method, the quantification of cilazapril and hydrochlorothiazide was performed by using the absorbances read at 210.4 nm. 250.2 nm and 270.6 nm in the zero-order spectra of their mixture; relative standard deviations of the method were found to be 1.26 % and 0.81 % for cilazapril and hydrochlorothiazide, respectively. These two methods have been successfully applied to a tablet containing these drugs.     

Spectrophotometric Determination of Neomycin With 2,4-Dinitrofluorobenzene

Abstract

A spectrophotometric method is described for the determination of neomycin based on the reaction with 2,4-dinitrofluorobenzene. the best conditions for the reaction were obtained by using 0.02 M borate buffer (pH 9.0) as diluent, under ambient conditions after 50 minutes of reaction.     

Search For A New Reagents From The Nitrosoamine Group For Spectrophotometric Determination Of Sulphur Dioxide

Abstract

p-Nitrosodiphenylamine as a representative of nitrosoamine group was tested as a new reagent for the spectrophotometric determination of SO₂. A mixture containing: p-nitrosodiphenylamine, formaldehyde, HCl, di-methylformamide and water was added to the aqueous test solutions of sulphites forming after 5 min, a blue complex with Λ_max=675 nm stable for one hour. The Lambert-Beer law was obeyed in the 0 to 50 /ug SO₂/cm³ range. Molar absorptivity was equal to 2000 and the specific absorption was 0.062. The investigations should lead to search for other reagents from the nitrosoamine group suitable for this purpose.     

Spectral Investigation on Ruthenium(III)-allyl Thiourea System

Abstract

Ruthenium(III) forms a 1:2 complex with allyl thiourea. Conformity to Beer's law was observed for up to 12 pg/ml of ruthenium, in acidic medium.

The molar absorptivity of the complex is 1.66E+04 1 mol^?1 cm^?1, at 270 nm; the Sandell's sensitivity of the reaction for ruthenium is 0.0061 μg cm^?2 per 0.001 absorbance unit.

The tolerance to diverse ions is quite satisfactory.

The infrared spectra of allyl thiourea and of its ruthenium complex, recorded in the 2.5 - 50 μ region, reveal that only sulphur-to-ruthenium bonds are present in the complex.

A comparison with the main, most recent, spectrophotometric reagents for ruthenium is reported. The present method has the advantages of simplicity and reasonable sensitivity.     

Simultaneous Analysis of Cimetidine and Ranitidine in Human Plasma by HPLC

Abstract

A rapid method for the simultaneous quantitation of the H₂-receptor antagonist drugs cimetidine and ranitidine in human plasma by isocratic ion-pair reverse-phase HPLC is described. The method involves a simple organic extraction step of the alkalinized plasma containing added internal standard followed by back extraction of the extract with dilute acetic acid and subsequent analysis of the aqueous acidic phase on a reverse-phase (C18) column. The eluting solvent was acetonitrile-water (20:80 v/v) containing 0.005 mole/litre octanesulphonic acid and was monitored at 229 nm. The run time for the assay was 12.5 minutes, with a detection limit for cimetidine of 50 ng/m1/(0.2 μmole/1) and that for ranitidine was 20 ng/ml (0.06 umole/1).     

Simultaneous Spectrophotometric Estimation and Validation of Three Component Tablet Formulation Containing Pioglitazone Hydrochloride,Metformin Hydrochloride and Glibenclamide

Abstract

Simultaneous estimation of active ingredients in multicomponent pharmaceutical products normally requires the use of separation techniques, such as HPLC, HPTLC, or GC, followed by their quantitation. Presented here are two spectrophotometric methods that do not require prior separation for simultaneous estimation of three drugs—pioglitazone HCl, metformin HCl, and glibenclamid—in a tablet formulation. Shimadzu UV 1700, capable of multicomponent analysis, was used for quantitation. In method I, absorbance of the sample solution was measured at 285 nm and 300 nm for the estimation of pioglitazone HCl and glibenclaimide, and at 237 nm for estimation of metformin hydrochloride, respectively. Method II is based on a multiwavelength spectroscopic method. Recording the absorbances of standard solutions at 237 nm, 268 nm, 280 nm, and 300 nm were processed by means of statistical calculations and results of the sample solution were obtained. All three drugs obey Beer's law in the concentration ranges used for the methods. The result of the analysis for both methods were tested and validated for various parameters according to ICH guidelines. The utility of the developed methods has been demonstrated by an analysis of commercial formulation containing all the three drugs.     

Determination of Chlordiazepoxide and Its Metabolites in Plasma by High Pressure Liquid Chromatography

Abstract

A rapid, sensitive and specific high pressure liquid chromatographic (HPLC) assay was developed for the determination of chlordiazepoxide and its metabolites from plasma. The assay involves extraction of chlordiazepoxide and its metabolites into diethyl ether from plasma buffered to pH 9. The overall recovery of chlordiazepoxide is 80 ± 5.0% (S.D.) and the sensitivity limit of detection is 50 to 100 ng/ml of plasma, using a 1 ml specimen. The assay was used in the determination of plasma levels of chlordiazepoxide and its metabolites in man following oral administration of chlordiazepoxide. HCl.

The chromatographic behavior of other clinically important benzodiazepines and their major metabolites is also reported.     

Simultaneous Determination of Dipyrone and Papaverine in Pharmaceutical Formulation using PLS Regression and UV Spectrophotometry

Abstract

A combination of sodium dipyrone and papaverine hydrochloride is used as an analgesic and antispasmodic drug. A simple and rapid procedure is proposed for simultaneous determination of these drugs in commercial formulations (Melpaz^®) based on partial least squares (PLS) regression and UV spectrophotometric measurements in the range of 218–300 nm. The calibration set was built with 25 solutions in concentrations ranging from 15.0–35.0 mg ml^?1 for dipyrone and from 0.5–1.5 mg ml^?1 for papaverine in methanol. The relative standard deviation (RSD) was 1.05% for dipyrone and 1.55% for papaverine in pharmaceutical formulations. The percent of relative recovery was 95.9% for dipyrone and 95.2% for papaverine. Figures of merit, such as accuracy, precision, sensitivity and adjust were also determined. The methodology was validated by using an independent method, based on high performance liquid chromatography (HPLC).     

Extraction-Spectrophotometric or -Atomic Absorption Spectrophotometric Determination of Titanium Using Caffeic Acid and a Liquid Ion Exchanger

Abstract

A selective and sensitive method for the extraction followed by a spectrophotometric or atomic absorption spectrophotometric determination of titanium(IV) in trace amounts is described. The molar absorptivity of the caffeic acid-Aliquat 336 complex is 5.7 × 10⁴ l mol^?1 cm^?1 at 380 nm; the yellow coloured complex obeys Beer's law in the range 0.05–1.2 mg/l of titanium in the final extract. The method is applied to the preconcentration, separation and determination of titanium(IV) in steel, industrial effluents and environmental samples.