Kinetic and Conventional Spectrophotometric Determination of Bumadizone in its Tablets via Oxidative Coupling with 3-Methyl-2-Benzothiazolinone Hydrazone

Two simple, sensitive and accurate spectrophotometric methods have been developed for the determination of bumadizone in bulk drug and its tablets. Both methods based on the oxidative coupling reaction with 3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH) and measuring the absorbance of the developed colors by direct or kinetic spectrophotometric method. Upon treatment of a mixture of the chromogenic reagent and drug with cerium (IV) ammonium sulfate (method I) or ferric chloride (method I), a red or violet color was developed immediately or after 30 minutes measurable at 557 nm for method I or II, respectively. The absorbance-concentration plots were rectilinear over the ranges of 1-10 μg/mL (r = 0.9999) for method I and 2-16 μg/mL (r = 0.9998) for method II. The detection limits were  0.15 and 0.27 μg/mL & the quantitation limits were 0.46 and 0.84 μg/mL for methods I and II, respectively. Different experimental parameters affecting the development and stability of the reactions products were studied and optimized. The proposed methods were applied successfully to the determination of bumadizone in its tablets, and the results obtained were in good agreement with those obtained using a comparison  method.Â

Simultaneous Determination of Sitagliptin and Metformin in Pharmaceutical Preparations by Capillary Zone Electrophoresis and its Application to Human Plasma Analysis

A novel, quick, reliable and simple capillary zone electrophoresis CZE method was developed and validated for the simultaneous determination of sitagliptin (SG) and metformin (MF) in pharmaceutical preparations. Separation was carried out in fused silica capillary (50.0 cm total length and 43.0 cm effective length, 49 μm i.d.) by applying a potential of 15 KV (positive polarity) and a running buffer containing 60 mM phosphate buffer at pH 4.0 with UV detection at 203 nm. The samples were injected hydrodynamically for 3 s at 0.5 psi and the temperature of the capillary cartridge was kept at 25 °C. Phenformin was used as internal standard (IS). The method was suitably validated with respect to specificity, linearity, limit of detection and quantitation, accuracy, precision, and robustness. The method showed good linearity in the ranges of 10–100 μg/mL and 50–500 μg/mL with limits of detection of 0.49, 2.11 μg/mL and limits of quantification of 1.48, 6.39 μg/mL for SG and MF, respectively. The proposed method was successfully applied for the analysis of the studied drugs in their synthetic mixtures and co-formulated tablets without interfering peaks due to the excipients present in the pharmaceutical tablets. The method was further extended to the in-vitro determination of the two drugs in spiked human plasma. The estimated amounts of SG/MF were almost identical with the certified values, and their percentage relative standard deviation values (% R.S.D.) were found to be #1.50% (n = 3). The results were compared to a reference method reported in the literature and no significant difference was found statistically

Spektrofluorimetrijsko određivanje ciklopiroks olamina prevođenjem u ternarni kompleks s Tb(III) i EDTA

A highly sensitive and selective spectrofluorimetric method was developed for the determination of ciclopirox olamine in raw material and in dosage forms. The proposed method is based on the formation of a ternary complex with Tb(III) in the presence of ethylenediaminetetraacetic acid. It was found that this complex manifests intense fluorescence at λem 489 and 545 nm with excitation at 295 nm. Different experimental parameters affecting the fluorescence intensity of the complex were carefully studied and incorporated into the procedure. Under the described conditions, the method is applicable over the concentration range of 30150 and 1070 ng mL-1 with minimum detectability of 6.7 and 0.9 ng mL-1 at λem 489 and 545 nm, respectively. The mean percentage recovery at λem 489 and λem 545 nm ranged between 98.7 and 100.2 for the pure substance, solution, and cream. Relative error of 0.10.4% and RSD up to 0.9% were estimated at λem 489 and 545 nm. A proposal of the reaction pathway is given.Razvijena je vrlo osjetljiva i selektivna spektrofluorimetrijska metoda za određivanje antimikotika ciklopiroks olamina, kao čiste supstancije i u ljekovitim oblicima. Metoda se temelji na stvaranju kompleksa s Tb(III) u prisutnosti etilendiamintetraoctene kiseline. Nakon ekscitacije pri 295 nm taj kompleks intenzivno fluorescira pri λem 489 i 545 nm. Proučavani su različiti eksperimentalni parametri koji utječu na intenzitet fluorescencije kompleksa. Za opisane uvjete metoda se može primijeniti u koncentracijskom području 30150 i 10 70 ng mL-1. Minimalna koncentracija koja se može odrediti je 6,7, odnosno 0,9 ng mL-1 na λem 489, odnosno 545 nm. Analitički povrat pri λem 489 i λem 545 nm iznosio je 98,7100,2% za čistu supstanciju, otopinu i kremu. Relativna pogreška metode je 0,10,4%, a relativna standardna devijacija 0,9%. Predložena je jednažba kemijske reakcije

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

Utilization of oxidation-reduction reaction of Folin-Ciocalteu’s phenol reagent in colorimetric determination of amlodipine in pharmaceutical dosage form

A simple visible spectrophotometric method has been developed for determination of amlodipine in commercial tablets. Amlodipine (AMO) is 1,4-dihydropyridine derivative, this group when reacted with Folin-Ciocaluts phenol reagent in presence of 10% sodium carbonate, intense blue color was formed that exhibits maximum absorbance at wave length 745 nm. The intensity of color was found to be affected by many parameters. Optimization of the method parameters was done. The method was validated over a concentration range of 10 to 110 µg/mL. The values of each validation items were within the acceptable range for precision and accuracy. The lower limit for quantitation and lower of detection were founded to be 3.21 and 9.72 µg/mL, respectively. The proposed method was successfully applied to the quantitative determination of amlodipine in tablets without interference from tablet additives. The simplicity and accuracy of this method will allow many laboratories to determine the concentration of amlodipine in dosage form in easy way

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