Application of first-derivative UV-spectrophotometry, TLC-densitometry and liquid chromatography for the simultaneous determination of mebeverine hydrochloride and sulpiride

Potentiometric determination of mebeverine hydrochloride antispasmodic drug based on molecular docking with different ionophores host-guest inclusion as a theoretical study

The scientific community has continued to pay particular attention to potentiometric sensors based on ion-selective membrane sensors as an energy-efficient, easy-to-use method suitable for microfabrication. To this end, potentiometric ion-selective sensors were used as an alternative green analytical instrument. Three distinct sensors relying on various ionophores were built and assessed. A cationic exchanger, tetra phenyl borate, was used in the polyvinyl chloride polymeric plasticized matrix using di octyl phthalate, where α, β, and γ cyclodextrins were utilized as ionophores. A comparative potentiometric analysis was carried out using three ion-selective sensor designs: α, β, and γ cyclodextrins sensors. β-Cyclodextrin significantly reduced the detection limit and improved the discriminative performance of mebeverine hydrochloride (MBV) in the pharmaceutical dosage form over α- and γ-cyclodextrins in the presence of other interfering chemicals. Additionally, a significant connection was made between the practical perspective and a theoretical investigation based on computational research. Nernstian potentiometric results for the optimum sensor were obtained for MBV in the range of concentrations 1.0 × 10^-2 to 1.0 × 10^-6 M, its slope was -58.70 ± 0.12 mV per decade with lower detection limits 4.50 × 10^-7 M. This computational molecular docking investigation clarified that the binding sites and modes were in good agreement with the experiment results. This investigation was applied to expect the interaction between MBV and the proposed sensors to ensure which ionophores were the best for MBV.

Implementation of Two Chromatographic Methods for Simultaneous Quantitation of Thioctic Acid, Benfotiamine and Cyanocobalamin

Two accurate and sensitive chromatographic methods have been introduced and validated for the simultaneous determination of thioctic acid, benfotiamine and cyanocobalamin in bulk powders and in their pharmaceutical formulation. Method A is reversed-phase ultra performance liquid chromatographic method with an isocratic elution, where a rapid separation was accomplished on a Zorbax C8 column using a mobile phase of acetonitrile:0.05 M phosphate buffer (pH 6 adjusted by o-phosphoric acid) (23:77, v/v). The retention times (tR) were 0.578, 0.852 and 1.376 for cyanocobalamin, benfotiamine and thioctic acid, respectively. The separated peaks were revealed at 210.0 nm. Method B is a thin-layer densitometric method where the separation of the studied drugs was carried out on silica gel plates using methanol-chloroform-heptane-1-sulphonic acid sodium salt (0.4%) (7:3:0.1, by volume) as a mobile phase, and scanning of the separated bands was done at 240.0 nm. The retardation factor (Rf) values were 0.17, 0.48 and 0.75 for cyanocobalamin, benfotiamine and thioctic acid, respectively. Validation of the methods was achieved following ICH guidelines and the applied methods succeeded to determine the cited drugs in their pure forms and capsules. Results were statistically compared to the manufacturer's method where no significant difference was observed.

Simultaneous HPLC Determination of Chlordiazepoxide and Mebeverine HCl in the Presence of Their Degradation Products and Impurities

A simple, rapid, and sensitive RP-HPLC method was developed and validated for the simultaneous determination of chlordiazepoxide (CDO) and mebeverine HCl (MBV) in the presence of CDO impurity (2-amino-5-chlorobenzophenone, ACB) and MBV degradation product (veratric acid, VER). Separation was achieved within 9 min on a BDS Hypersil phenyl column (4.5 mm × 250 mm, 5 µm particle size) using a mobile phase consisting of acetonitrile: 0.1 M potassium dihydrogen phosphate: triethylamine (35 : 65 : 0.2, v/v/v) in an isocratic mode at a flow rate of 1 mL/min. The pH of the mobile phase was adjusted to 4.5 with orthophosphoric acid and UV detection was set at 260 nm. A complete validation procedure was conducted. The proposed method exhibited excellent linearity over the concentration ranges of 1.0–100.0, 10.0–200.0, 2.0–40.0, and 2.0–40.0 µg/mL for CDO, MBV, VER, and ACB, respectively. The proposed method was applied for the simultaneous determination of CDO and MBV in their coformulated tablets with mean percentage recoveries of 99.75 ± 0.62 and 98.61 ± 0.38, respectively. The results of the proposed method were favorably compared with those of a comparison HPLC method using Studentt-test and the variance ratioF-test. The chemical structure of MBV degradation product was ascertained by mass spectrometry and IR studies.

Development and Validation of Micellar-Enhanced Spectrofluorimetric Method for Determination of Sulpiride in Pharmaceutical Formulations and Biological Samples

Sensitive and simple spectrofluorometric method has been developed and validated for the quantification of sulpiride in pure, commercial formulations, human plasma and urine in the presence of sodium dodecyl sulphate (SDS) surfactant micelle. The experimental parameters like buffer, surfactant type and volume were studied. A linear relationship was found between sulpiride concentration and fluorescence intensity in the range of 0.02 μg mL–1–7.0 μg mL–1 containing 0.2 M sodium dodecyl sulphate with λex 292 nm and λem 343 nm with a correlation coefficient of 0.9987. The limit of detection (LOD) and limit of quantification (LOQ) was found to be 1.9 × 10–2 μg mL–1 and 5.9 × 10–2 μg mL–1 respectively. The proposed method was successfully applied for the determination of sulphiride in pure and dosage form; the percentage recoveries agreed well with the label value. The effect of common excipients used as additive in pharmaceutical formulations was studied and no interferences was found. Similarly the effect of some common cations and compounds present in urine and plasma were also investigated and the method was found free of interferences. The method was further extended to the in-vitro determination of sulphiride in spiked human plasma and urine samples with percentage recoveries from 98.33%–99.75% and 95.67%–101.67% respectively. The results of the proposed method have been compared with the literature HPLC method and no significant difference was found between them.

Comparative study of novel spectrophotometric methods manipulating ratio spectra: an application on pharmaceutical ternary mixture of omeprazole, tinidazole and clarithromycin

Three simple, specific, accurate and precise spectrophotometric methods manipulating ratio spectra are developed for simultaneous determination of omeprazole (OM), tinidazole (TN) and clarithromycin (CL) in tablets. Method A, is an extended ratio subtraction one (EXRSM). Method B is a ratio difference spectrophotometric one (RDSM), while method C is mean centering of ratio spectra (MCR). The calibration curves are linear over the concentration range of 1-20 μg/mL, 10-60 μg/mL and 0.25-1.0 mg/mL for OM, TN and CL, respectively. The specificity of the developed methods is investigated by analyzing laboratory prepared mixtures of the three drugs and their combined dosage form. Standard deviation values are less than 1.5 in the assay of raw materials and tablets. The three methods are validated as per ICH guidelines and accuracy, precision, repeatability and robustness are found to be within the acceptable limits.

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.

Quantitative HPLC analysis of mebeverine, mesalazine, sulphasalazine and dispersible aspirin stored in a Venalink monitored dosage system with co-prescribed medicines

An HPLC method for the quantitative analysis of mebeverine HCl, 5-aminosalicylic acid (5-ASA), sulphasalazine and dispersible aspirin has been developed and then applied to these specific medicines when stored, with other medications, in Venalink blister packs (monitored dosage system) for periods of up to 35 days. Chromatographic separation was achieved on a reversed-phase C(12) column with an isocratic mixture of methanol, water and acetic acid as the mobile phase. The method was validated regarding: accuracy, precision, detection limits, quantification limits, specificity and robustness.

Synthesis, spectroscopic and thermal characterization of sulpiride complexes of iron, manganese, copper, cobalt, nickel, and zinc salts. Antibacterial and antifungal activity

Sulpiride (SPR; L) is a substituted benzamide antipsychotic which is reported to be a selective antagonist of central dopamine receptors and claimed to have mood-elevating properties. The ligation behaviour of SPR drug is studied in order to give an idea about its potentiality towards some transition metals in vitro systems. Metal complexes of SPR have been synthesized by reaction with different metal chlorides. The metal complexes of SPR with the formula [MCl(2)(L)(2)(H(2)O)(2)].nH(2)O [M=Mn(II), Co(II), Ni(II), Cu(II) and Zn(II); n=0-2] and [FeCl(2)(HL)(H(2)O)(3)]Cl.H(2)O have been synthesized and characterized using elemental analysis (CHN), electronic (infrared, solid reflectance and (1)H NMR spectra) and thermal analyses (TG and DTA). The molar conductance data reveal that the bivalent metal chelates are non-electrolytes while Fe(III) complex is 1:1 electrolyte. IR spectra show that SPR is coordinated to the metal ions in a neutral monodentate manner with the amide O. From the magnetic and solid reflectance spectra, octahedral geometry is suggested. The thermal decomposition processes of these complexes were discussed. The correlation coefficient, the activation energies, E*, the pre-exponential factor, A, and the entropies, DeltaS*, enthalpies, DeltaH*, Gibbs free energies, DeltaG*, of the thermal decomposition reactions have been derived from thermogravimetric (TG) and differential thermogravimetric (DTG) curves. The synthesized ligand and its metal complexes were also screened for their antibacterial and antifungal activity against bacterial species (Escherichia coli and Staphylococcus aureus) and fungi (Aspergillus flavus and Candida albicans). The activity data show that the metal complexes are found to have antibacterial and antifungal activity than the parent drug and less than the standard.

Two charge-transfer complex spectrophotometric methods for the determination of sulpiride in pharmaceutical formulations

Two simple, rapid, accurate and sensitive spectrophotometric methods are described for the determination of sulpiride. They are based on charge transfer complexation between the drug as n-electron donor and p-chloranilic acid as π acceptor or iodine as σ-acceptor. These give highly coloured complexes with absorption maxima at 518 and 363, 294 nm, respectively. Beer’s law linear ranges were 13.7–341.4 and 1.7–20.5 µg mL−1 for the p-chloranilic acid and iodine methods. The methods were successfully applied to the determination of the drug in Dogmatil® Fort tablets and the results compared with the official method. The complex association constants and standard free energy changes were calculated using Benesi-Hildebrand plots.

Development of membrane selective electrode for determination of the antipsychotic sulpiride in pharmaceuticals and urine

The construction and electrochemical response characteristics of a poly(vinyl chloride) (PVC) membrane selective electrode for the determination of sulpiride (SPD) are described. The sensing membrane comprised an ion-exchanger formed between the protonated drug and tetraphenylborate (TPB(-)) in a plasticized PVC matrix. The influence of membrane composition on the electrode response was studied. The electrode showed a fast, stable and Nernstian response over a sulpiride concentration range (1 × 10(-4) - 1 × 10(-2) M) with a mean slope of 58.4 ± 0.9 mV dec(-1) of concentration, a mean detection limit of 4.2 × 10(-5) ± 1.2 × 10(-5) M, a wide working pH range (2 - 8) and a fast response time (< 15 s). The electrode showed good selectivity towards sulpiride with respect to some inorganic and organic compounds. When the electrode was applied to the determination of sulpiride in pharmaceuticals and human urine, a high percentage of recovery was attained with no need for sample pretreatment procedures because of the lack of interfering matrix effects.

Spectrophotometric determination of benzydamine HCl, levamisole HCl and mebeverine HCl through ion-pair complex formation with methyl orange

A simple, rapid and sensitive spectrophotometric method has been proposed for the assay of benzydamine HCl (BENZ), levamisole HCl (LEV) and mebeverine HCl (MBV) in bulk and pharmaceutical formulations. The method based on the reaction of the selected drugs with methyl orange (MO) in buffered aqueous solution at pH 3.6. The formed yellow ion-pair complexes were extracted with dichloromethane and measured quantitatively with maximum absorption at 422 nm. The analytical parameters and their effects on the reported systems are investigated. The extracts are intensely colored and very stable at room temperature. The calibration graphs were linear over the concentration range of 2-10 microg ml(-1) for BENZ, 6-24 microg ml(-1) for LEV and 4-14 microg ml(-1) for MBV. The stoichiometry of the reaction was found to be 1:1 in all cases and the conditional stability constant (K(f)) of the complexes have been calculated. The proposed method was successfully extended to pharmaceutical preparations-tablets. Excipients used as additive in commercial formulations did not interfere in the analysis. The proposed method can be recommended for quality control and routine analysis where time, cost effectiveness and high specificity of analytical technique are of great importance.

A validated chiral HPLC method for the determination of mebeverine HCl enantiomers in pharmaceutical dosage forms and spiked rat plasma

A new, precise, simple and accurate HPLC method was developed for the first time to separate and determine mebeverine enantiomers. Enantiomeric resolution was achieved on a cellulose Tris (3,5-dimethylphenyl carbamate) column known as Chiralcel OD, with UV detection at 263 nm. The mobile phase consisted of n-hexane, isopropyl alcohol and triethylamine (90:9.9:0.1 v/v/v). Sample run time was 18 min. On using the chromatographic conditions described, mebeverine enantiomers were well resolved with mean retention times of about 11 and 14 min. A linear response (r>0.999) was observed over the concentration range 0.5-20 microg/mL racemic mebeverine. Precision, accuracy and stability were studied according to ICH guidelines. The limit of detection was found to be 0.05 microg/mL for each enantiomer of mebeverine. The proposed method was applied for analysis of mebeverine in commercially available tablets dosage formulations. Examples of application to biological samples are also given. Reanalysis of samples several weeks after the initial analysis showed no degradation of mebeverine.

Canine versus in vitro data for predicting input profiles of L-sulpiride after oral administration

The objective of this study was to assess the relative usefulness of canine versus in vitro data sets in the prediction of absorption of L-sulpiride (a low permeability compound) from an immediate and an extended release formulation. To reduce species differences on upper gastrointestinal residence times, human and canine data were collected in the fed state. In vitro permeability data (that were additionally confirmed by rat perfusion data) were obtained from the literature. In vitro release data were obtained in media simulating the gastric composition (without and with simultaneous protein digestion) and intestinal composition in the fed state. The results showed that, regardless of the formulation, canine input profiles were vastly different from human profiles at times longer than 2h after administration and led to 2.7 times higher total amount absorbed in dogs. In contrast, reliable in vitro permeability data in combination with in vitro release data collected in biorelevant media led to successful prediction of the human input profile; regardless of the dosage form, simulated and actual mean input profiles differed by less than 20%.

Potentiometric flow injection analysis of mebeverine hydrochloride in serum and urine

Four PVC membrane electrodes for the determination of mebeverine hydrochloride (MvCl) were fabricated and fully characterized in terms of composition, life span, usable pH range, working concentration range and temperature. The membranes of these electrodes consist of mebeverinium-silicotungstate (Mv-ST), silicomolybdate (Mv-SM), phosphotungstate (Mv-PT), or phosphomolybdate (Mv-PM) ion-associations dispersed in PVC matrix with dibutyl phthalate plasticizer. The electrodes showed near-Nernstian response over the concentration range of 4.0 x 10(-6) to 1.0 x 10(-2)M MvCl and were applied to the potentiometric determination of mebeverinium ion in pharmaceutical preparations, serum and urine in steady state and flow injection (FI) conditions with average recoveries of 96.4-102 % and relative standard deviations of 0.132-1.86%. The electrodes exhibit good selectivity for MvCl with respect to a large number of inorganic cations, organic cations, sugars and amino acids. The sensitivities of these electrodes are high enough to measure as low as 1.86 microg/ml of MvCl which permit the determination of the Ksp values of the ion-associates used. The proposed potentiometric methods offer the advantages of simplicity, accuracy, automation feasibility and applicability to turbid and colored sample solutions.

Recent Developments of Derivative Spectrophotometry and Their Analytical Applications

Articles about the development of derivative spectrophotometric methods and analytical applications of derivative spectrophotometry (DS) published in the last nine years (since 1994) are reviewed.

Simultaneous Determination of Mebeverine Hydrochloride and Sulpiride Using the First Derivatives of Ratio Spectra and Chemometric Methods

Two methods are described for the simultaneous determination of mebeverine hydrochloride (MB) and sulpiride (SU) in their combinations. The first method depends on the first derivative of the ratio spectra by measurement of the amplitudes at 263.7 and 234.9 nm for MB and SU, respectively. The linear ranges and detection limits are 4.0-40.0 and 0.72 microg/ml for MB and 1.0-10.0 and 0.34 microg/ml for SU. In the second case, a chemometric (classical least squares) method was developed. The concentration data matrices were obtained by using different concentrations of pure drugs in 0.1 M HCl. The absorbance data matrix corresponding to each concentration data matrix was obtained by the measurements of absorbances in the range 200-300 nm in their zero order spectra; then calibration was obtained by using the absorbance data matrix and the concentration data matrix for the prediction of the unknown concentrations of MB and SU in their mixture. The numerical values were calculated by using Matlab R12 version 6.0 and Origin 5.0 software. The procedures do not require any separation steps. These two methods were successfully applied for assaying the pharmaceutical formulation, of Colona tablets.

Spectrophotometric microdetermination of nefopam, mebevrine and phenylpropanolamine hydrochloride in pharmaceutical formulations using alizarins

Simple and rapid spectrophotometric procedures have been established for quantitation of nefopam hydrochloride (NF) mebevrine hydrochloride (MB) and phenylpropanolamine hydrochloride (PP). The procedures are based on the reaction between the examined drugs (NF, MB and PP) and alizarin (I), alizarin red S (II), alizarin yellow G (III) and quinalizarin (IV) producing ion-pair complexes which can be measured at the optimum wavelength. The optimization of the reaction conditions is investigated. Beer's law is obeyed in the concentration ranges 0.5-30.0 microg ml(-1). The molar absorptivity, Sandell sensitivity, detection and quantification limits are also calculated. The correlation coefficient was > or =0.9988 (n=6) with a relative standard deviation (R.S.D.) of < or =1.3, for six determinations of 20 microg ml(-1). The methods are successfully applied to the determination of NF, MB and PP in their pharmaceutical formulations.

Dissolution media simulating the intralumenal composition of the small intestine: physiological issues and practical aspects

The objective of this study was to test various aspects of dissolution media simulating the intralumenal composition of the small intestine, including the suitability of the osmolality-adjusting agents and of the buffers, the substitution of crude sodium taurocholate (from ox bile) for pure sodium taurocholate and the substitution of partially hydrolysed soybean phosphatidylcholine for egg phosphatidylcholine. It was concluded that biorelevant media should contain sodium as the major cation species to better reflect the physiology. However, the use of non-physiologically relevant buffers is inevitable, especially for simulation of the fed state in the small intestine. The buffers used may affect the solubility product of weakly basic compounds with pK(a)(s) higher than about 5, the solubility of extremely highly lipophilic compounds due to salting in/out properties of the anion of the buffer and the stability of the dissolving compound. It is prudent in relevant situations to run an additional dissolution test in a modified fed state simulated intestinal fluid (FeSSIF) (or fasted state simulated intestinal fluid (FaSSIF), where applicable) containing alternative buffer species. Although a mixture of bile salts is physiologically more relevant than pure sodium taurocholate, this issue seems to be of practical importance in only a few cases. Adequate simulations in these cases will probably require the use of a number of pure substances and could substantially increase the cost of the test. Finally, unless the drug is extremely lipophilic (ca. logP> 5), egg phosphatidylcholine can be substituted by partially hydrolysed soybean phosphatidylcholine.

Determination of Sulpiride by Capillary Electrophoresis with End-Column Electrogenerated Chemiluminescence Detection

Background: Capillary electrophoresis (CE) with tris(2,2′-bipyridyl)ruthenium(II) [Ru(bpy)32+]-electrogenerated chemiluminescence (ECL) detection is a promising method for clinical analysis. In this study, a method combining CE with Ru(bpy)32+ ECL (CE-ECL) detection that can be applied to amine-containing clinical species was developed, and the performance of CE-ECL as a quantitative method for determination of sulpiride in human plasma or urine was evaluated.

Methods: Sulpiride was separated by capillary zone electrophoresis in uncoated fused-silica capillaries [50 cm × 25 μm (i.d.)] filled with phosphate buffer (pH 8.0) and a driving voltage of +15 kV, with end-column Ru(bpy)32+ ECL detection. A platinum disc electrode was used as working electrode. Sulpiride in human plasma or urine samples (100 μL) was extracted by a double-step liquid-liquid extraction procedure, dried under nitrogen at 35 °C in a water bath, and reconstituted with 100 μL of filtered water. The extraction solvent was ethyl acetate–dichloromethane (5:1 by volume).

Results: Under optimum conditions (pH 8.0 phosphate buffer, injection for 6 s at 10 kV, and +1.2 V as detection potential), separation of sulpiride was accomplished within 4 min. The calibration curve was linear over a concentration range of 0.05–25.0 μmol/L, and the limit of detection was 2.9 × 10−8 mol/L for sulpiride. Intra- and interday CVs for ECL intensities were &lt;6%. Extraction recoveries of sulpiride were 95.6–101% with CVs of 2.9–6.0%. The method was clinically validated for patient plasma and urine samples.

Conclusions: CE combined with Ru(bpy)32+ ECL is reproducible, precise, selective, and enables the analysis of sulpiride in human plasma and urine. It thus is of value for rapid and efficient analysis of amine-containing analytes of clinical interest.

Simultaneous determination of benzocaine and cetylpiridinium chloride in tablets by first-derivative spectrophotometric method

A new spectrophotometric method for the simultaneous determination of benzocaine and cetylpiridinium chloride in pharmaceutical tablets, which does not require any preliminary separation or treatment of the samples, is described. The quantitative determination of both drugs was carried out using the first derivative values measured at 231.40 and 310.00 nm for benzocaine and at 220.70 nm for cetylpiridinium chloride using the zero-crossing method. The calibration graphs were linear in the ranges from 10 to 25 mg/l of benzocaine and from 4 to 20 mg/l of cetylpiridinium chloride. The developed method was successfully applied for the assay of pharmaceutical tablets and proved to be simple, sensitive and selective. Thermogravimetric techniques, Karl Fischer and loss on drying were also used for a stoichiometric evaluation of the substances studied.