Atomic Emission Spectrometric Determination of Antazoline,Hydralazine, Amiloride,Thiamine and Quinine Based on Formation of Ion Associates with Ammonium Reineckate.

Abstract

Ion-associate complexes of Antazoline HC1 (I), Hydralazine HC1 (II), Amiloride HC1 (III), Thiamine HC1 (IV) and Quinine sulphate (V) with ammonium reineckate were precipitated and their solubilities were studied as a function of pH, ionic strength and temperature. Saturated solutions of each ion-associate under the optimum precipitation conditions were prepared and the metal ion-content in the supernatent was determined. The solubility products were thus elucidated at different temperatures. A new accurate and precise method using direct coupled plasma-atomic emission spectrometry for the determination of the investigated drugs in pure solutions and in pharmaceutical preparations is described. The drugs can be determined by the present method in the ranges 0.3-3.0, 0.19-1.96, 0.3-3.0, 0.33-3.37 and 0.78-7.82 mg/25 ml solutions of I, II, III, IV and V, respectively.     

A Kinetic spectrophotometric method for determination of amlodipine and Nifedipine in pharmaceutical preparations

A simple, accurate, sensitive and economical procedure for the estimation of amlodipine besylate and nifedipine, both in pure and dosage forms, has been developed. The method is based on the reduction of iron(III) by the studied drugs and subsequent interaction of iron(II) with ferricyanide to form Prussian blue. The reaction develops through a slow kinetics and completes in about 10 min. Both initial slope and fixed time methods were used to derive calibration graphs. The resulted calibration equations were linear in the concentration ranges of 1.0-20.0 and 3.0-19.0 μg ml^-1 for AML and NIF, and the detection limits were 0.10 and 0.19 μg ml^-1, respectively. Seven replicate analyses of solutions containing three different levels of each drug resulted in very low relative error of prediction (less than 1.6%) and relative standard deviation (less than 4%) confirming accuracy and precision of the proposed method. The proposed method was applied to the determination of these drugs in pharmaceutical formulations and excellent recoveries were obtained.     

Extractive colorimetric method for the determination of dothiepin hydrochloride and risperidone in pure and in dosage forms

Three rapid, simple, reproducible and sensitive extractive colorimetric methods (A--C) for assaying dothiepin hydrochloride (I) and risperidone (II) in bulk sample and in dosage forms were investigated. Methods A and B are based on the formation of an ion pair complexes with methyl orange (A) and orange G (B), whereas method C depends on ternary complex formation between cobalt thiocyanate and the studied drug I or II. The optimum reaction conditions were investigated and it was observed the calibration curves resulting from the measurements of absorbance concentration relations of the extracted complexes were linear over the concentration range 0.1--12 microg ml(-1) for method A, 0.5--11 mug ml(-1) for method B, and 3.2--80 microg ml(-1) for method C with a relative standard deviation (RSD) of 1.17 and 1.28 for drug I and II, respectively. The molar absorptivity, Sandell sensitivity, Ringbom optimum concentration ranges, and detection and quantification limits for all complexes were calculated and evaluated at maximum wavelengths of 423, 498, and 625 nm, using methods A, B, and C, respectively. The interference from excipients commonly present in dosage forms and common degradation products was studied. The proposed methods are highly specific for the determination of drugs I and II, in their dosage forms applying the standard additions technique without any interference from common excipients. The proposed methods have been compared statistically to the reference methods and found to be simple, accurate (t-test) and reproducible (F-value).     

New method for detection and spectrophotometric determination of quinones

The reaction between 3-phenylthiazolidine-2,4-dione (I) and p-benzoquinone (II), tetrachloro-p-benzoquinone (III), and 1,4-naphthoquinone (IV) in ammoniacal medium is applied for detection and spectrophotometric determination of quinones. The absorbance-concentration relationship is linear up to 18 μg/ml of quinone concentration. The lower limits of identification in the detection reaction are 2.5, 3.0, and 1 μg for (II), (III), and (IV), respectively, which reflect high sensitivity. The reaction between (I) and quinones is proved to be a condensation reaction and highly selective.     

Acetylacetone-formaldehyde reagent for the spectrophotometric determination of some sulfa drugs in pure and dosage forms

A new simple and sensitive spectrophotometric procedure for the determination of sulfacetamide sodium (I), sulfadiazine (II), sulfadimidine (III) and sulfathiazole (IV) is based on the reaction of the drug with acetylacetone-formaldehyde reagent to give a yellow product having _max at 400 nm. Optimization of the reaction conditions has been investigated. A linear correlation was obtained between absorbance at _max and the concentration. The Beer's law limits of I, II, III and IV are 4–80, 4–72, 4–60 and 4–80 g/ml, respectively. For more accurate results, Ringbom optimum concentration ranges were evaluated to be 6–76, 8–66, 6–56 and 8–75 g/ml for I, II, III and IV, respectively. The molar absorptivities and Sandell sensitivities for all sulfa drugs under consideration were evaluated. Relative standard deviations of 0.98, 1.07, 0.86 and 0.79% were obtained for I, II, III and IV, respectively. The method has been compared to the official method and found to be simple, accurate (t-test) and reproducible (F-test). The developed procedures were applied for bulk sulfa drugs and some of their dosage forms without interferences from additive and common prescribed drugs.     

Reversed-Phase High Performance Liquid Chromatographic and Thin Layer Chromatographic Methods for the Simultaneous Determination of Benazepril Hydrochloride and Hydrochlorothiazide in Cibadrex Tablets

ABSTRACT

Two procedures were developed for simultaneous determination of benazepril hydrochloride (I) and hydrochlorothiazide (II) in pure, laboratory made mixtures and in pharmaceutical dosage form “Cibadrex tablets® using reversed phase high performance liquid chromatographic and thin layer chromatographic methods.

For reversed phase HPLC, a new very sensitive, rapid, selective method was developed. The linearity ranges were 32-448 ng/20 μl and 40-560 ng/20 μl for benazepril hydrochloride and hydrochlorothiazide, respectively. The corresponding recoveries were 99.38 ± 1.526 and 99.2 ± 1.123.

The minimum detection limits were 7 ng/20 μl and 14 ng/20 μl for benazepril hydrochloride and hydrochlorothiazide respectively.

On the other hand, a new, simple, sensitive and fast thin layer chromatographic scanning densitometric method was developed for simultaneous determination of benazepril hydrochloride and hydrochlorothiazide using ethyl acetate: methanol: ammonia (85: 20: 10 v/v) as the developing system. The R_f values were 0.33 & 0.68 for benazepril hydrochloride and hydrochlorothiazide respectively. The minimum detection limit obtained was 0.12 μg/spot for benazepril hydrochloride and 0.24 μg/spot for hydrochlorothiazide. The mean percentage recoveries were 100.04 ± 1.102 and 99.31 ± 1.009 for benazepril hydrochloride and hydrochlorothiazide respectively.

The two proposed methods were simple, precise, sensitive and could be successfully applied for the determination of pure, laboratory made mixtures and pharmaceutical dosage forms. The results obtained were compared with those obtained by A ^1%.     

Spectrophotometric determination of trazodone, amineptine and amitriptyline hydrochlorides through ion-pair formation using methyl orange and bromocresol green reagents

A simple and rapid extraction spectrophotometric procedure has been developed for the determination of tricyclic anti-depressant drugs such as trazodone (TZH), amineptine (APH) and amitriptyline (ATPH) hydrochlorides in pure form and in different dosage forms. The method involves the formation of intense yellow ion-pairs between these drugs under investigation and methyl orange (MO) and bromocresol green (BCG) reagents followed by their extraction with 1,2-dichloroethane and quantitative microdetermination at 420 and 410 nm using MO or BCG, respectively. The optimum experimental conditions for the ion-pairs formation are established. The method permits the determination of TZH, APH and ATPH over a concentration range of 2-50, 2-50 and 1-25 microg ml(-1) for TZH, APH and ATPH, using MO and 1-25 microg ml(-1) for TZH, APH and ATPH, using BCG, respectively. The Sandell sensitivity (S) is found to be 0.106, 0.1071 and 0.0907 g cm(-2) for TZH, APH and ATPH, respectively, using MO reagent and 0.0788, 0.0661 and 0.0494 g cm(-2) for TZH, APH and ATPH, respectively, using BCG. The method is applicable for the assay of the investigated drugs in different dosage forms and the results are in good agreement with those obtained by the official method.     

Utility of NBD-Cl for the spectrophotometric determination of some skeletal muscle relaxant and antihistaminic drugs

A simple, accurate, precise and sensitive colorimetric method for the determination of some skeletal muscle relaxant drugs, namely orphenadrine citrate (I), baclofen (II), antihistaminic drugs as acrivastine (III) and fexofenadine hydrochloride (IV) is described. This method is based on the formation of charge transfer complex with 4-chloro-7-nitro-2,1,3-benzoxadiazole (NBD-Cl) in non-aqueous medium. The orange color products were measured at 472, 465, 475 and 469 nm for drugs I, II, III and IV, respectively. The optimization of various experimental conditions was described. Beer's Law was obeyed in the range (2.5-17.5), (5-70), (2.5-25) and (10-50)microg/ml for drugs I, II, III and IV, respectively. The molar absorptivity (epsilon), sandell sensitivity, detection((LOD)) and quantitation limits((LOQ)) are calculated. The procedure was favorably applied for determination of certain pharmaceutical dosage forms containing the studied drugs. The obtained results were compared with the official and reported methods. There were no significant differences between proposed, reported and the official methods.     

Determination of procaine, benzocaine and tetracaine by sequential injection analysis with permanganate-induced chemiluminescence detection

Local anaesthetics procaine hydrochloride (I), benzocaine (II), and tetracaine hydrochloride (III) were determined by the technique of sequential injection analysis (SIA) with chemiluminescence (CL) detection. The CL was emitted during the oxidation of the analytes by permanganate in aqueous sulphuric acid in the presence of various CL enhancers (4-hydroxybiphenyl, Rhodamine B, glycolaldehyde, glutaraldehyde and formic acid). The optimum enhancer or reagent concentrations, order and volumes of the injected zones were: 0.37 M formic acid (40, 23 or 28 mul for I-III, respectively), sample (40 mul), 2.3 M H(2)SO(4) (20, 16 or 18 mul for I-III, respectively), and 0.5 mM KMnO(4) (19, 13 or 15 mul for I-III, respectively). After a double (or single for III) reversal of the flow the mixed zone was pushed into the detector at a flow rate of 100 mul s(-1). The transient CL signal was recorded at >/=390 nm. The calibration graphs relating the intensity of the emission (peak heights) to the concentration of the analytes were curvilinear (a second order polynomial showed the best fit) and they were suitable for determining I-III in the ranges 0.5-50, 0.5-25 and 0.2-25 mug ml(-1), respectively. The limits of detection (3sigma) were 0.3 mug ml(-1) for I and II and 0.1 mug ml(-1) for III. The sample throughput was 120 h(-1). The relative standard deviations were 相似文献   

Spectrophotometric determination of trazodone, amineptine and amitriptyline hydrochlorides through ion-pair formation with molybdenum and thiocyanate

Extraction spectrophotometric method has been developed for the determination of tricyclic drugs such as trazodone (TZH), amineptine (APH) and amitriptyline (ATPH) hydrochlorides in pure form and in the dosage forms coming from different Egyptian markets. The method based on the formation of ion-pairs between these drugs under investigation and inorganic complex of Mo(V)-thiocyanate followed by its extraction with methylene chloride. The optimum conditions for the ion-pairs formation are established. The method permits the determination of TZH, APH and ATPH over the concentration range of 2-28, 2-32 and 1-30 microg ml(-1), respectively. The Sandell sensitivity (S) is found to be 0.105, 0.138 and 0.118 g cm(-2) for TZH, APH and ATPH, respectively. The SD is found to be 0.16-0.377, 0.12-0.259 and 0.091-0.286 and the R.S.D. are 0.14-0.55, 0.12-0.399 and 0.095-0.485 for TZH, APH and ATPH, respectively. The method is applicable for the assay of the investigated drugs in different dosage forms and the results are in good agreement with those obtained by the official method.     

Complex compounds of terbium(III) with some nonsteroidal anti-inflammatory drugs and their analytical applications

Luminescence properties of the complexes of terbium(III) with nonsteroidal anti-inflammatory drugs (ibuprofen and orthofen) were studied. It was demonstrated that in the presence of organic bases (2,2’-dipyridyl and 1,10-phenanthroline) mixed-ligand complexes are formed and the luminescence intensity of terbium(III) increases by a factor of up to 250. The optimum complexation conditions were determined. It was proposed to use these complexes as analytical forms for the luminescence determination of nonsteroidal anti-inflammatory drugs (ibuprofen and orthofen) in pharmaceutical dosage forms. The detection limits are 2 and 0.05 μg/mL, respectively.     

Spectrophotometric Microdetermination of Some Pharmaceutically Impor tant Aminoquinoline Antimalarials, as Ion-Pair Complexes

 A simple, rapid, accurate and sensitive spectrophotometric method for the microdetermination of some pharmaceutically important aminoquinoline antimalarials, namely amodiaquine dihydrochloride (I), chloroquine phosphate (II) and primaquine phosphate (III) is described. The method is based on the interaction of these drugs with calmagite indicator to give highly coloured ion-pair complexes which exhibit maximum absorption at 663, 665 and 666 nm, respectively, Beer’s law is obeyed in the concentration ranges 1.0–25.0, 1.0–28.0 and 1.0–33.0 μg/ml for the drugs I, II and III, respectively. For more accurate analysis, the Ringbom optimum concentration ranges are 2.5–22.5, 2.0–26.0 and 3.0–30.0 μg/ml, respectively. The apparent molar absorptivities were calculated. Statistical treatment of the experimental results indicates that the method is sufficiently accurate and precise. The accuracy of the method is indicated by the recovery (99.8±1.4%) and the precision by the relative standard deviation (>1.5%). The proposed method has been applied to the determination of these drugs in certain formulations, with results that compared favourably with those obtained by the official methods. Received November 2, 1998. Revision February 29, 2000.     

Colorimetric determination of amoxycillin in pure form and in pharmaceutical preparations

A simple and selective method for the determination of amoxycillin in pure form and in pharmaceutical preparations is described. The procedure is based on the reaction of amoxycillin with 4-nitrophenol (I), 2,4-dinitrophenol (II), 3,5-dinitrobenzoic acid (III) or 3,5-dinitrosalicylic acid (IV) in alkaline medium. The method has been used for the determination of 1-24 mug/ml of amoxycillin trihydrate in solution. The method is selective for the determination of amoxycillin in the presence of its degradation products, other antibiotics and different amines that are normally encountered in dosage forms.     

Spectrofluorimetric determination of drugs containing active methylene group using N1-methyl nicotinamide chloride as a fluorigenic agent

A spectrofluorimetric method was described for the determination of drugs containing active methylene groups adjacent to carbonyl groups. The method was applied successfully to the determination of three life saving cardiovascular drugs, with narrow therapeutic indices: pentoxifylline (I), propafenone hydrochloride (II) and acebutolol hydrochloride (III), in laboratory-prepared mixtures, in commercial tablets and in plasma samples. The method involved the reaction of each of the tested drugs with N1-methyl nicotinamide chloride (NMNCl) in the presence of alkali, followed by addition of formic acid, where highly fluorescent reaction products were produced. The produced fluorescence were measured quantitatively at 472 nm (lambdaex 352 nm), 409 nm (lambdaex 310 nm) and 451 nm (lambdaex 266 nm) for (I), (II), and (III) respectively. The method was linear over concentration ranges of 10-1000 microg/ml , 0.2-12 microg/ml and 0.08-10 microg/ml in standard solutions for (I), (II), and (III) respectively. In spiked human plasma samples, calibration graphs were linear over concentration ranges of 20-1000 microg/ml, 0.2-15 microg/ml and 0.08-10 microg/ml for (I), (II), and (III) respectively. The method showed good accuracy, specificity and precision in both laboratory-prepared mixtures and spiked human plasma samples. The proposed method is simple, with low instrumentation requirements, suitable for quality control application, bioavailability and bioequivalency studies.     

Spectrophotometric Determination of Trimethoprim in Pure Form and in Pharmaceutical Preparations using Bromothymol Blue,Bromocresol Green and Alizarin Red S

ABSTRACT

Simple, sensitive and selective methods for the determination of trimethoprim (TMP) in pure form and in pharmaceutical formulations are described. The methods are based on the reaction of TMP as a π-electron donor with bromothymol blue (BTB), bromocresol green (BCG) and alizarin red S (ARS) as electron acceptors. The coloured products are quantified spectrophotometrically at their corresponding λ_max.

Beer's law is obeyed in case of BTB in the range 2.9-23.2 μg/ml (CHCl₃), 2.9-20.0 μg/ml (CH₂Cl₂) and 5.0-29.0 μg/ml (ClC₆H₅), in the case of BCG 2.9-27.5 μg/ml (H₂O/alc.), 2.9-18.3 μg/ml (CHCl₃) and 2.9-20.3 μg/ml (CH₂Cl₂) and for ARS in the range 3.0-12.0 μg/ml in H₂O/alc medium.

The specific absorptivities, molar absorptivities, Sandell sensitivities, standard deviations and percent recoveries are evaluated. Application of the suggested methods to dosage forms is presented and compared with the pharmacopoeial method. The interference from additives and sulfa compounds, especially sulfamethoxazole, has been overcome by extraction into chloroform or methylene chloride.     

Spectrofluorimetric determination of guanethidine sulphate, guanoxan sulphate and amiloride hydrochloride in tablets and in biological fluids using 9,10-phenanthraquinone

A highly sensitive spectrofluorimetric method for the determination of some drugs of the monosubstituted guanidine derivatives in laboratory made tablets, in spiked human serum and in urine samples is presented. The method is based on the reaction of guanethidine sulphate (I), guanoxan sulphate (II) and amiloride hydrochloride (III) with 9,10-phenanthraquinone (IV) to give highly fluorescent derivatives. The linearity ranges were found to be 0.06-0.96 mug/ml for (I) and (II) and 0.04-0.28 mug/ml for (III), with relative standard deviation less than 2%. Mean percentage recoveries for tablets were found to be 99.9 +/- 1.3, 100.5 +/- 1.1 and 100.0 +/- 1.6 for I, II and III, respectively. For I and III the results are highly correlated with the B.P. methods. Using the synchronous fluorimetry, differentiation between I and II was possible. Chloroform, dichloromethane and ethyl acetate have been used to extract I, II and III, respectively from serum and urine at basic pH, followed by applying the proposed fluorimetric method. Percentage recoveries were found to be 95.7-102.2%. The limit of detection is 0.04 mug/ml for I and II and 0.02 mug/ml for III.     

Spectrophotometric Determination of Metoclopramide and Oxybuprocaine Through Ion Pair Formation with Thiocyanate and Molybdenum(V) or Cobalt(II)

Abstract

Two spectrophotometric methods involve the formation of two different ion pairs between the drug and inorganic complexes, Mo(V) and Co(II) thiocyanates followed by their extraction with dichlor?methane and o-nitrotoluene, respectively. The optimum conditions for the ion pair formation are established. The methods permit the determination of metoclopramide and oxybuprocaine hydrochlorides over a concentration range of 1-20 μg ml^?1 and 20–240 μg ml^?1 using Mo(V) and Co(II) thiocyanates, respectively. Molar ratio of drug to Mo(V) or Co(II) indicates a 2:1 ratio for the two drugs studied in the presence of excess thiocyanate concentration. Results of the analysis of drug substances and their dosage forms by the proposed methods are in good agreement with those obtained by the official methods.     

Indirect atomic absorption and atomic emission spectrometric determination of antazoline,hydralazine and amiloride hydrochlorides and quinine sulphate

Ion-association complexes of antazoline HCl [I], hydralazine HCl [II], amiloride HCl [III] and quinine sulphate [IV] with [Co(SCN)₄]^2– and [Co(NO₂)₆]^3– were precipitated and the excess unreacted cobalt complex was determined. A new method using atomic emission and atomic absorption spectrometry for the determination of the above drugs in pure solutions and pharmaceutical preparations is given. The drugs can be determined in the ranges 0.3–3.0, 0.19–1.96, 0.3–3.0, and 0.78–7.82 mg/25 ml solutions of I, II, III, and IV, respectively, with mean relative standard deviations of 0.65–2.03 % and recovery values of 95.76–101.2% indicating high precision and accuracy.     

Generic nonextractive spectrophotometric method for determination of 4-quinolone antibiotics by formation of ion-pair complexes with beta-naphthol

This paper describes the development of a generic spontaneous nonextractive spectrophotometric method for determination of 13 pharmaceutically important 4-quinolone antibiotics. The method was based on the formation of yellow-colored water-soluble ion-pair complexes between 2% (w/v) beta-naphthol reagent and each of the studied drugs in sulfuric acid medium at room temperature. The formed ion-pair chromogens have maximum absorption peaks in the range of 365-391 nm. The concentrations of the reagents and the experimental conditions affecting the reaction were optimized. Under the optimum conditions, linear relationships with good linear coefficients (0.9987-0.9995) were found between the absorbance and concentration of the investigated drugs in the range of 10-350 microg/mL. The assay limits of detection and quantitation were 1-9.9 and 3.4-32.9 microg/mL, respectively. The precision of the method was satisfactory; the values of relative standard deviations did not exceed 2%. The proposed method was successfully applied to the analysis of the investigated drugs in pure and pharmaceutical dosage forms with good accuracy and precision; the percentages of label claim ranged from 97.8-102.8 +/- 0.35-1.60%. The results obtained by the proposed spectrophotometric method were comparable with those obtained by the official or reported methods. The proposed method is superior to all the previously reported ion-pair formation-based methods in terms of simplicity because it did not involve extraction procedures for the ion-pair complex. Therefore, this method might be recommended for routine use in quality control laboratories for analysis of the investigated 4-quinolone antibiotics in their pure forms, as well as in pharmaceutical dosage forms.     

Kinetic and Spectrophotometric Determination of Thioctic Acid in Bulk and Pharmaceutical Formulations

Three simple and sensitive spectrophotometric methods were developed for the determination of thioctic acid in bulk and in its pharmaceutical preparations using iron(III) as an oxidizing agent. Method A is based on kinetic investigation of oxidation reaction of the drug with iron(III) and a subsequent chelation of the produced iron(II) with ferricyanide to form prussian blue colored product at room temperature for a fixed time of 15 minutes at 750 nm. Methods B and C are based on oxidation of the studied drug with iron(III). The equivalent iron(II) produced is allowed to react with either o‐phenanthroline or bipyridyl to give colored species measurable at 510, 522 nm, respectively. Regression analysis of Beer‐Lambert plots showed a good correlation in the concentration ranges of 0.4–4 μg/mL with a detection limit of 0.095 μg/mL for method A and 0.5–5 μg/mL with detection limits 0.137 and 0.127 for method B and C, respectively. The three methods were successfully applied for the determination of the drug in its dosage forms. The percentage recoveries were 99.88 ± 1.40, 99.98 ± 1.26 and 100.64 ± 1.07, respectively.