Micellar liquid chromatographic method for the simultaneous determination of norfloxacin and tinidazole in pharmaceutical dosage forms and human plasma

A micellar liquid chromatographic method was developed for the simultaneous analysis of a binary mixture of norfloxacin and tinidazole (NOR and TIN) in dosage forms and human plasma. The analysis was carried out using a Waters Symmetry® C18 column (250 mm x 4.6 mm i.d., 5 µm particle size). The running mobile phase consisting of 0.15 M sodium dodecyl sulphate (SDS), 0.3 % triethylamine (TEA), 5 % n-propanol, the pH was adjusted to 4 by addition of 0.02 M orthophosphoric acid pumped at a flow rate 1.0 mL/min with UV at 275 nm. Calibration curves were linear over the range 1-28 and 1.5-42 µg/mL for NOR and TIN, respectively. The quantification limits were 0.7 and 1.0 µg /mL for NOR and TIN respectively. The proposed method was successfully applied for the simultaneous determination of NOR and TIN in human plasma without prior precipitation of protein. The mean percentage recoveries of bioavailability test in human plasma (n = 3) were 90.31 ± 4.22 and 90.05 ± 1.3 for NOR and TIN, respectively.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Micellar liquid chromatographic method for the simultaneous determination of norfloxacin and tinidazole in pharmaceutical dosage forms and human plasma

A micellar liquid chromatographic method was developed for the simultaneous analysis of a binary mixture of norfloxacin and tinidazole (NOR and TIN) in dosage forms and human plasma. The analysis was carried out using a Waters Symmetry® C18 column (250 mm x 4.6 mm i.d., 5 µm particle size). The running mobile phase consisting of 0.15 M sodium dodecyl sulphate (SDS), 0.3 % triethylamine (TEA), 5 % n-propanol, the pH was adjusted to 4 by addition of 0.02 M orthophosphoric acid pumped at a flow rate 1.0 mL/min with UV at 275 nm. Calibration curves were linear over the range 1-28 and 1.5-42 µg/mL for NOR and TIN, respectively. The quantification limits were 0.7 and 1.0 µg /mL for NOR and TIN respectively. The proposed method was successfully applied for the simultaneous determination of NOR and TIN in human plasma without prior precipitation of protein. The mean percentage recoveries of bioavailability test in human plasma (n = 3) were 90.31 ± 4.22 and 90.05 ± 1.3 for NOR and TIN, respectively.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Simultaneous determination of sulpiride and mebeverine by HPLC method using fluorescence detection: application to real human plasma

A new simple, rapid and sensitive reversed-phase liquid chromatographic method was developed and validated for the simultaneous determination of sulpiride (SUL) and mebeverine Hydrochloride (MEB) in the presence of their impurities and degradation products. The separation of these compounds was achieved within 6 min on a 250 mm, 4.6 mm i.d., 5 m particle size Waters®-C18 column using isocractic mobile phase containing a mixture of acetonitrile and 0.01 M dihydrogenphosphate buffer (45:55) at pH = 4.0. The analysis was performed at a flow rate of 1.0 mL/min with fluorescence-detection at excitation 300 nm and emission at 365 nm. The concentration-response relationship was linear over a concentration range of 10- 100 ng/mL for both MEB and SUL with a limit of detection 0.73 ng/mL and 0.85 ng/mL for MEB and SUL respectively. The proposed method was successfully applied for the analysis of both MEB and SUL in bulk with average recoveries of 100.22 ± 0.757% and 99.96 ± 0.625% respectively, and in commercial tablets with average recoveries of 100.04 ± 0.93% and 100.03 ± 0.376% for MEB and SUL respectively. The proposed method was successfully applied to the determination of MEB metabolite (veratic acid) in real plasma simultaneously with SUL. The mean% recoveries (n = 3) for both MEB metabolite (veratic acid) and SUL were 100.36 ± 2.92 and 99.06 ± 2.11 for spiked human plasma respectively. For real human plasma, the mean% recoveries (n = 3) were and respectively

Preconcentration and Detection of Gefitinib Anti-Cancer Drug Traces from Water and Human Plasma Samples by Means of Magnetic Nanoparticles

Along of widespread application of anti-cancer drug Gefitinib (GEF), it appears in human body fluids as well as clinical wastewater. Consequently, a reliable and easy-to-adapt detection technique is of essential importance to quantify the drug in different media. The extraction and quantitative detection of anti-cancer drug Gefinitib (GEF) is demonstrated based on a straightforward and efficient magnetic nanoparticle-assisted preconcentration route from water and human plasma samples. Iron oxide magnetic nanoparticles (Fe3O4) have been prepared with an average particle size of 15 nm and utilized as extractible adsorbents for the magnetic solid-phase extraction (MSPE) of GEF in aqueous media. The method is based on MSPE and preconcentration of GEF followed by High-Performance Liquid Chromatography-Ultraviolet Detection (HPLC-UV). The yield of GEF extraction under the optimum MSPE conditions were 94% and 87% for water and plasma samples, respectively. The chromatographic separation was carried out isocratically at 25 °C on a Phenomenex C8 reversed phase column (150 mm × 4.6 mm, with 5 µm particle size). The proposed method was linear over concentration ranges of 15.0–300.0 and 80.0–600.0 ng/mL for water and plasma samples with limits of detection of 4.6 and 25.0 ng/mL in a respective order. Relative standard deviations (%RSD) for intra-day and inter-day were 0.75 and 0.94 for water samples and 1.26 and 1.70 for plasma samples, respectively. Using the magnetic nanoparticles (MNPs) as loaded drug-extractors made the detection of the anti-cancer drug environmentally friendly and simple and has great potential to be used for different drug-containing systems

Validated spectrophotometric methods for determination of Alendronate sodium in tablets through nucleophilic aromatic substitution reactions

<p>Abstract</p> <p>Background</p> <p>Alendronate (ALD) is a member of the bisphosphonate family which is used for the treatment of osteoporosis, bone metastasis, Paget's disease, hypocalcaemia associated with malignancy and other conditions that feature bone fragility. ALD is a non-chromophoric compound so its determination by conventional spectrophotometric methods is not possible. So two derivatization reactions were proposed for determination of ALD through the reaction with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) and 2,4-dinitrofluorobenzene (DNFB) as chromogenic derivatizing reagents.</p> <p>Results</p> <p>Three simple and sensitive spectrophotometric methods are described for the determination of ALD. Method I is based on the reaction of ALD with NBD-Cl. Method II involved heat-catalyzed derivatization of ALD with DNFB, while, Method III is based on micellar-catalyzed reaction of the studied drug with DNFB at room temperature. The reactions products were measured at 472, 378 and 374 nm, for methods I, II and III, respectively. Beer's law was obeyed over the concentration ranges of 1.0-20.0, 4.0-40.0 and 1.5-30.0 μg/mL with lower limits of detection of 0.09, 1.06 and 0.06 μg/mL for Methods I, II and III, respectively. The proposed methods were applied for quantitation of the studied drug in its pure form with mean percentage recoveries of 100.47 ± 1.12, 100.17 ± 1.21 and 99.23 ± 1.26 for Methods I, II and III, respectively. Moreover the proposed methods were successfully applied for determination of ALD in different tablets. Proposals of the reactions pathways have been postulated.</p> <p>Conclusion</p> <p>The proposed spectrophotometric methods provided sensitive, specific and inexpensive analytical procedures for determination of the non-chromophoric drug alendronate either per se or in its tablet dosage forms without interference from common excipients.</p> <p>Graphical abstract</p> <p><display-formula><graphic file="1752-153X-6-25-i3.gif"/></display-formula></p

Validated stability-indicating spectrofluorimetric methods for the determination of ebastine in pharmaceutical preparations

Two sensitive, selective, economic, and validated spectrofluorimetric methods were developed for the determination of ebastine (EBS) in pharmaceutical preparations depending on reaction with its tertiary amino group. Method I involves condensation of the drug with mixed anhydrides (citric and acetic anhydrides) producing a product with intense fluorescence, which was measured at 496 nm after excitation at 388 nm

Spectrofluorimetric determination of sertraline in dosage forms and human plasma through derivatization with 9-fluorenylmethyl chloroformate

<p>Abstract</p> <p>Background</p> <p>Sertraline is primarily used to treat major depression in adult outpatients as well as obsessive-compulsive, panic and social anxiety disorders in both adults and children. A survey of the literature reveals that most of the reported methods are either insufficiently sensitive or tedious and require highly sophisticated and dedicated instrumentation. The proposed method is considered to be specific for determination of SER in presence of its metabolite (deaminated form).</p> <p>Results</p> <p>A sensitive, simple and specific spectrofluorimetric method was developed for the determination of sertraline (SER) in pharmaceutical formulations and biological fluids. The method is based on its reaction with 9-fluorenylmethyl chloroformate (FMOC-Cl) in borate buffer of pH 8.0 to yield a highly fluorescent derivative peaking at 315 nm after excitation at 265 nm. The different experimental parameters affecting the development and stability of the reaction product were carefully studied and optimized. The fluorescence concentration plot was rectilinear over the range of 0.05-1.0 μg mL^-1with a lower detection limit of 5.34 × 10^-3μg mL^-1and limit of quantitation of 0.016 μg mL^-1.</p> <p>Conclusions</p> <p>The proposed method was successfully applied to the analysis of commercial tablets and the results obtained were in good agreement with those obtained using the reference method. Furthermore, the method was applied for the determination of SER in spiked and real human plasma. The mean % recovery (n = 3) was 94.33 ± 1.53 and 92.00 ± 2.65, respectively. A proposal of the reaction pathway was postulated.</p

Spectrophotometric determination of tizanidine and orphenadrine via ion pair complex formation using eosin Y

A simple, sensitive and rapid spectrophotometric method was developed and validated for the determination of two skeletal muscle relaxants namely, tizanidine hydrochloride (I) and orphenadrine citrate (II) in pharmaceutical formulations. The proposed method is based on the formation of a binary complex between the studied drugs and eosin Y in aqueous buffered medium (pH 3.5). Under the optimum conditions, the binary complex showed absorption maxima at 545 nm for tizanidine and 542 nm for orphenadrine. The calibration plots were rectilinear over concentration range of 0.5-8 μg/mL and 1-12 μg/mL with limits of detection of 0.1 μg/mL and 0.3 μg/mL for tizanidine and orphenadrine respectively. The different experimental parameters affecting the development and stability of the complex were studied and optimized. The method was successfully applied for determination of the studied drugs in their dosage forms; and to the content uniformity test of tizanidine in tablets

Utility of certain nucleophilic aromatic substitution reactions for the assay of pregabalin in capsules

<p>Abstract</p> <p>Background</p> <p>Pregabalin (PG) is an anticonvulsant, analgesic and anxiolytic drug. A survey of the literature reveals that all the reported spectrophotometric methods are either don't offer high sensitivity, need tedious extraction procedures, recommend the measurement of absorbance in the near UV region where interference most probably occurs and/or use non specific reagent that don't offer suitable linearity range.</p> <p>Results</p> <p>Two new sensitive and simple spectrophotometric methods were developed for determination of pregabalin (PG) in capsules. Method (I) is based on the reaction of PG with 1,2-naphthoquinone-4-sulphonate sodium (NQS), yielding an orange colored product that was measured at 473 nm. Method (II) is based on the reaction of the drug with 2,4-dinitrofluorobenzene (DNFB) producing a yellow product measured at 373 nm. The different experimental parameters affecting the development and stability of the reaction product in methods (I) and (II) were carefully studied and optimized. The absorbance-concentration plots were rectilinear over the concentration ranges of 2-25 and 0.5-8 μg mL^-1for methods (I) and (II) respectively. The lower detection limits (LOD) were 0.15 and 0.13 μg mL^-1and the lower quantitation limits (LOQ) were 0.46 and 0.4 μg mL^-1for methods (I) and (II) respectively.</p> <p>Conclusion</p> <p>The developed methods were successfully applied to the analysis of the drug in its commercial capsules. The mean percentage recoveries of PG in its capsule were 99.11 ± 0.98 and 100.11 ± 1.2 (n = 3). Statistical analysis of the results revealed good agreement with those given by the comparison method. Proposals of the reaction pathways were postulated.</p

Synchronous fluorescence spectrofluorimetric method for the simultaneous determination of metoprolol and felodipine in combined pharmaceutical preparation

A rapid, simple and sensitive synchronous specrtofluorimetric method has been developed for the simultaneous analysis of binary mixture of metoprolol (MTP) and felodipine (FDP). The method is based upon measurement of the synchronous fluorescence intensity of the two drugs at Δλ of 70 nm in aqueous solution. The different experimental parameters affecting the synchronous fluorescence intensities of the two drugs were carefully studied and optimized. The fluorescence intensity-concentration plots were rectilinear over the ranges of 0.5-10 μg/mL and 0.2-2 μg/mL for MTP and FDP, respectively. The limits of detection were 0.11 and 0.02 μg/mL and quantification limits were 0.32 and 0.06 μg/mL for MTP and FDP, respectively. The proposed method was successfully applied for the determination of the two compounds in their commercial tablets and the results obtained were favorably compared to those obtained with a comparison method