Analysis of pharmaceutical preparations containing antihistamine drugs by micellar liquid chromatography

Green micellar factorial design optimized first derivative synchronous spectrofluorimetric method for tripelennamine and diphenhydramine determination in pharmaceutical gel

A green micellar synchronous spectrofluorimetric method was developed and validated for simultaneous determination of tripelennamine hydrochloride and diphenhydramine in bulk and combined pharmaceutical formulation. Synchronous fluorescence of tripelennamine hydrochloride and diphenhydramine was determined using Δλ = 60 nm. The first derivative of synchronous fluorescence was computed to resolve overlap in the synchronous fluorescence spectra. Tripelennamine hydrochloride was quantified at 375 nm, whereas diphenhydramine was quantified at 293 nm; each is the zero-crossing point of the other. As diphenhydramine exhibited weak native fluorescence, micelle enhancement upon incorporation of sodium dodecyl sulfate was considered. Two-level full factorial design was carried out to optimize experimental parameters. Optimum conditions involved using SDS (2% w/v) along with Teorell and Stenhagen buffer (pH 9). The method was found to be linear over the range 0.2-4.5 and 0.2-5 μg/mL for tripelennamine and diphenhydramine, respectively, with limits of detection 0.211 and 0.159 μg/mL. The method was successfully applied for simultaneous determination of tripelennamine hydrochloride and diphenhydramine in laboratory-prepared gel containing all possible excipients with mean percent recoveries ±SD 100.59 ± 0.79 and 98.99 ± 0.98 for tripelennamine hydrochloride and diphenhydramine, respectively. The proposed method was proved to be eco-friendly using different greenness assessment tools.

Green micellar liquid chromatographic method for simultaneous determination of antihistaminic drugs tripelennamine hydrochloride and diphenhydramine in pharmaceutical gel

A new green micellar liquid chromatographic method has been developed and validated for the simultaneous determination of diphenhydramine (DPH) and tripelennamine hydrochloride (TRP) using a micellar mobile phase consisting of 1 mM Tween 20 in phosphate buffer pH 4:isopropanol (85:15, %v/v). The method was linear in the range of 4-150 and 5-120 μg/mL for TRP and DPH, respectively. The method was successfully applied for the simultaneous determination of DPH and TRP in a laboratory-prepared gel containing all possible excipients with mean percent recoveries ± standard deviation of 100.346 ± 1.265 and 100.754 ± 1.117 for TRP and DPH, respectively. The method was validated according to the International Conference on Harmonization guidelines. The method is confirmed to have excellent greenness.

Analysis of canthin-6-one alkaloids derived from Eurycoma spp. by micellar liquid chromatography and conventional high-performance liquid chromatography: a comparative evaluation

Extracts of Eurycoma longifolia Jack (EL) and Eurycoma harmandiana Pierre (EH) contain numerous bioactive compounds and varying matrices that are challenging to separate using chromatographic techniques. Herein, micellar liquid chromatography (MLC) was used to analyze canthin-6-one alkaloids contained in these extracts, and the achieved performance was compared with that of a conventional high-performance liquid chromatography (HPLC) method. The optimal mobile phase of MLC corresponded to 15 : 85 (v/v) acetonitrile : water (pH 3) containing 110 mM sodium dodecyl sulfate and 10 mM NaH₂PO₄. The retention times of canthin-6-one-9-O-β-d-glucopyranoside, 9-hydroxycanthin-6-one, canthin-6-one, and 9-methoxycanthin-6-one were 4.78/15.42, 17.64/24.11, 32.84/38.27, and 39.04/39.86 min, respectively, in the cases of isocratic MLC and conventional HPLC. In both cases, the analyte resolution exceeded 1.5. The MLC elution behavior of the examined analytes was largely determined by their hydrophobicity and ionization. The sensitivity, precision, accuracy, and per-run acetonitrile consumption of the MLC method were comparable to those of the conventional HPLC method. However, the latter method exhibited higher performance for application to EL and EH samples, particularly those with low analyte concentrations and varying sample matrices. Overall, the analysis of canthin-6-one alkaloids using MLC was limited to trace analytes due to interference by the matrix.

A simple and sensitive LC-MS/MS method for determination of doxylamine in human plasma and its application in a bioequivalence study in healthy Chinese volunteers

A simple, rapid, sensitive and specific LC-MS/MS method was developed and validated for the quantitative determination of doxylamine in human plasma, using isotope doxylamine-d5 as internal standard (IS). The detection was conducted on a QTRAP 5500 tandem mass spectrometer coupled with electrospray ionization (ESI) source in positive ion mode. Quantification was achieved by positive electrospray ionization containing multiple reaction monitoring (MRM) transitions of m/z 271.0→182.0 for doxylamine and m/z 276.2→187.3 for IS. The mobile phase A was methanol, and mobile phase B was 20 mM ammonium acetate (0.2 % formic acid) in water, using a gradient elution procedure at a flow rate of 0.6 mL/min. The method was validated with a sensitivity of 0.500 ng/mL and a linear concentration range of 0.500-200 ng/mL. The inter-batch precision (%CV) was less than 5.4 %, and the accuracy deviation (%RE) ranged from - 10.6 % to 3.7 %; the inter-batch precision (%CV) was less than 6.6 %, and the accuracy deviation (%RE) was ranged from - 2.7 % to 0.1 %. The selectivity, sensitivity, extraction recovery, matrix effect, carryover, dilution reliability, stability and other characteristics were within the acceptable range. This validated method was successfully applied to a bioequivalence study that orally administered 25 mg of doxylamine succinate tablets in 60 healthy Chinese volunteers.

Application of Micellar Mobile Phase for Quantification of Sulfonamides in Medicated Feeds by HPLC-DAD

Rapid chromatographic procedure for quantification of five sulfonamides in medicated feeds are proposed. Satisfactory separation of sulfonamides from medicated feeds was achieved using a Zorbax Eclipse XDB C18 column (4.6 × 150 mm, 5 µm particle size) with a micellar mobile phase consisting of 0.05 M sodium dodecyl sulphate, 0.02 M phosphate buffer, and 6% propan-2-ol (pH 3). UV quantitation was set at 260 nm. The proposed procedure allows the determination of sulfaguanidine, sulfadiazine, sulfamerazine, sulfamethazine, and sulfamethoxazole in medicated feeds for pigs and poultry. Application of the proposed method to the analysis of five pharmaceuticals gave recoveries between 72.7% to 94.7% and coefficients of variations for repeatability and reproducibility between 2.9% to 9.8% respectively, in the range of 200 to 2000 mg/kg sulfonamides in feeds. Limit of detection and limit of quantification were 32.7–56.3 and 54.8–98.4 mg/kg, respectively, depending on the analyte. The proposed procedure for the quantification of sulfonamides is simple, rapid, sensitive, free from interferences and suitable for the routine control of feeds. In the world literature, we did not find the described method of quantitative determination of sulfonamides in medicated feeds with the use of micellar liquid chromatography.

Determination of six drugs used for treatment of common cold by micellar liquid chromatography

The use of organic solvents as eluants in RP-HPLC has an important role to decrease retention time and improve peak shape; however, it has high environmental impacts. Their production and disposal represent economic and biohazard problems. So, alternatives had to be introduced and studied to minimize such pollution. Combination of sodium dodecyl sulfate (SDS) together with polyoxyethylene-23-lauryl ether (Brij-35) was studied as an alternative to the presence of organic solvents on the separation performance of six active pharmaceutical ingredients. Response surface methodology was applied to test the impact of three independent variables; concentrations of SDS and Brij-35, as well as, pH of the mobile phase; on retention, peak symmetry, and resolution of the analytes using a rotatable central composite design. Significant variables were determined and the suggested models for predicting retention and resolution parameters were significant. Meanwhile, the common cold is the most abundant disease treated with over-the-counter (OTC) medications worldwide. In 2015, the USA recorded $9.56 billion total sales of OTC cold and cough medicaments alone, with average individual patient expenditure of $338. The worldwide sales and generics of common cold and cough products keep growing annually. The six active pharmaceutical molecules under study, namely, paracetamol, guaifenesin, pseudoephedrine, ibuprofen, chlorpheniramine, and dextromethorphan, are widely used in common cold products. The predicted optimum conditions were validated using mobile phase consisting of 93.6 mM SDS, 32.0 mM Brij-35, and 10.0 mM sodium dihydrogen phosphate, adjusted at pH 5.2, column temperature 35° C, and detection at 215-nm wavelength. The method was successfully applied to determine 12 different combination formulae of the analytes in their pharmaceutical products and was assessed for greenness on two novel metrics. A thorough comparison to previously reported methods was included and methods were assessed against greenness metrics Green Analytical Procedure Index and Analytical Greenness Metric to demonstrate superiority.

A comparative study of two novel validated spectrophotometric techniques for resolution of four-component mixtures with severely overlapping spectra

Two new smart spectrophotometric methods are developed and validated for the determination of the quatertnary mixture of paracetamol (acetaminophen), diphenhydramine, p-aminophenol, and N-oxide degradate of diphenhydramine. Method A is the novel triple divisor ratio difference method, where the triple divisor ratio spectrum of the component of interest shows a significant amplitude difference at two selected wavelengths where the three interfering substances are used as triple divisor and give constant amplitude all over the spectrum. The triple divisors are normalized spectra of tertiary mixtures containing 40 μg/mL of each of the 3 interfering components. The selected wavelengths are 256-290 nm, 220-230 nm, 230-245 nm and 275-260 nm for the 4 components, respectively. Method B is double divisor - ratio difference-dual wavelength, where the double divisor ratio spectrum of the component of interest shows a significant amplitude difference at two selected wavelengths where two interfering substances are used as double divisor and give constant amplitude all over the spectrum, while the third one shows zero amplitude difference at these two selected wavelengths. The double divisors used are normalized spectra of diphenhydramine /N-oxide degradate of diphenhydramine binary mixture for both paracetamol and p-aminophenol and paracetamol/p-aminophenol binary mixture for both diphenhydramine hydrochloride and its N-oxide degradate. The double divisors binary mixtures contain 40 μg/mL of each component. The selected wavelengths are 243-233 nm, 223.8-270.2 nm, 237-250 nm and 265-234.6 nm for the 4 compounds, respectively. Both methods were successfully applied for the quantification of the four components in laboratory prepared quaternary mixtures and for the quantification of paracetamol and diphenhydramine hydrochloride in panadol night® tablets. The results obtained by the developed methods were compared with those obtained by the United State Pharmacopeial method for the analysis of paracetamol and diphenhydramine, where no significant differences were found.

Application of HPTLC with Densitometry for Evaluation of the Impact of External Factors on Contents of Diphenhydramine in Its Solutions

The subject of durability of drugs is a very important problem investigated by researches. The method of accelerated aging is very often used for stability testing. It involves the influence of temperature, humidity, and light exposure. The aim of this work is estimation of contents of diphenhydramine in its standard solutions undergoing the impact of external factors, that is, temperature and UV light. The standard solutions of diphenhydramine were prepared in distilled water. The analysis of contents of compound investigated was carried out by use of HPTLC. Adsorption thin layer chromatography was performed on aluminum HPTLC plates precoated with silica gel 60F₂₅₄ using mixture of ammonia, methanol, and ethyl acetate as mobile phase. The solutions investigated were exposed to UV light as well as being heated in 40°C. The contents of diphenhydramine were measured in initial solution and during experiment. The additional peaks on densitograms as well as changes in color of solution were observed as a result of exposure to UV light which can give information about new substances, degradation products of diphenhydramine, which were created during experiment.

Electrochemical detection of chlorpheniramine maleate in the presence of an anionic surfactant and its analytical applications

Improvement of methods for the detection of an analyte at a low concentration with high sensitivity has become an important point of interest. An effort has been made to know the electrochemical behavior of chlorpheniramine maleate in the presence of an anionic surfactant. Voltammograms were obtained in the range of 6.0–11.2 pH, and the maximum peak current (IP) was observed at pH 10.4. Various physicochemical parameters were estimated, including the process on the surface of the electrode, which was found to be diffusion controlled, heterogeneous rate constant, number of electrons transferred, and charge transfer coefficient. Square wave voltammetry of chlorpheniramine maleate at the modified electrode exhibited a linear calibration curve in the concentration range of 1.0–100 μmol/L, with a limit of detection of 28 nmol/L. The proposed technique was successfully used for the determination of chlorpheniramine maleate in pharmaceuticals, as well as in biological samples.

RP-HPLC enantioseparation of β-adrenolytics using micellar mobile phase without organic solvents

Enantioseparation of a few commonly administered racemic β-adrenolytics (namely, carvedilol, betaxolol, salbutamol and bisoprolol) has been achieved using a water micellar mobile phase containing surfactants (sodium dodecyl sulphate and Brij-35) without organic solvents as a new approach in RP-HPLC. Two chiral derivatizing reagents based on enantiomerically pure (S)-(-)-levofloxacin were synthesized using N-hydroxysuccinimide and N-hydroxybenzotriazole as the activation auxiliaries. Diastereomeric derivatives of the chosen β-adrenolytics were synthesized under microwave irradiation in a very short reaction time. The (S)-(-)-levofloxacin moiety enhanced molar absorbance of the diastereomeric derivatives resulting in very low limit of detection (1.618 and 4.902 ng/mL, respectively, for diastereomeric derivatives of (RS)-betaxolol and better resolution with lower retention times (for all the analytes), in comparison to literature reports. There was 15-20 times less consumption of mobile phase because of lower retention time.

Development and validation of an ultra-performance liquid chromatography method for simultaneous analysis of 20 antihistaminics in dietary supplements

The purpose of this study was to develop and validate an ultra-performance liquid chromatography method for simultaneous analysis of 20 antihistamines (illegal additives) in dietary supplements. The limits of detection and quantitation of the method ranged from 1.5 to 2.5 µg/mL and from 20.0 to 50.0 µg/mL, respectively. The determination coefficient was >0.999, precisions were 0.2-5.1% (intra-day) and 0.1-8.8% (inter-day), and accuracies were 84.5-111.2% (intra-day) and 91.9-112.0% (inter-day). The mean recoveries of 20 targeted compounds from dietary supplements ranged from 75.4 to 119.3%. The relative standard deviations were <6.6% and complied with established international guidelines. The relative standard deviation of stability was <0.8%. Fifty-two commercially available dietary supplements were evaluated using this method, and were found to have none of the 20 antihistamines in significant abundance.

Recent theoretical and practical applications of micellar liquid chromatography (MLC) in pharmaceutical and biomedical analysis

Micellar liquid chromatography (MLC) is an analytical technique belonging to the wide range of reversed-phase liquid chromatographic (RP-LC) separation techniques. MLC with the use of surfactant solutions above its critical micellar concentration (CMC) and the addition of organic modifiers is currently an important analytical tool with still growing theoretical considerations and practical applications in pharmaceutical analysis of drugs and other biologically active compounds. The use of MLC as an alternative, relatively much faster in comparison to conventional chromatographic separation techniques has several advantages, especially as being suitable for screening pharmaceutical analysis. The analytical data received from MLC analysis are considered a useful source of information to predict passive drug absorption, drug transport and other pharmacokinetics and physicochemical measures of pharmaceutical substances. In the review several MLC assays for determination of drugs and other active compounds in biological samples were compared and critically discussed. The presented overview provides information on recent applications and achievements connected with the practical use of MLC. The review covers fields of interest related to theory and mechanism of MLC separation, direct applications of MLC in pharmaceutical analysis, including optimization and efficiency of separation with the use of modification of stationary phase and mobile phase compositions as well as the determination of physicochemical characteristics of drugs by MLC.

Determination of paracetamol: historical evolution

Paracetamol is a common analgesic and antipyretic drug that is used for the relief of fever, headaches and other minor aches and pains. Their determination in pharmaceuticals is of paramount importance, since an overdose of paracetamol can cause fulminating hepatic necrosis and other toxic effects. Many analytical methodologies have been proposed for the determination of paracetamol. The aim of the present study is to evaluate the utility of different techniques for quantification of paracetamol content in pharmaceutical formulations and biological samples.

Comparison between micellar liquid chromatography and capillary zone electrophoresis for the determination of hydrophobic basic drugs in pharmaceutical preparations

The determination of highly hydrophobic basic compounds by means of conventional reversed-phase liquid chromatographic methods has several drawbacks. Owing to the characteristics of micellar liquid chromatography (MLC) and capillary electrophoresis (CE), these techniques could be advantageous alternatives to reversed-phase chromatographic methods for the determination of these kinds of compounds. The objective of this study was to develop and compare MLC and CE methods for the determination of antipsychotic basic drugs (amitryptiline, haloperidol, perphenazine and thioridazine) in pharmaceutical preparations. The chromatographic determination of the analytes was performed on a Kromasil C(18) analytical column; the mobile phase was 0.04 m cetyltrimethylammonium bromide (CTAB), at pH 3, containing 5% 1-butanol, at a flow rate of 1 mL/min. The CE separation was performed in a fused-silica capillary with a 50 mm tris-(hydroxymethyl)-aminomethane buffer, pH 7, at an applied voltage of 20 kV, using barbital as internal stardard. The proposed methods are suitable for a reliable quantitation of these compounds in the commercial tablets and drops in terms of accuracy and precision and require a very simple pre-treatment of the samples. By comparing the performance characteristics and experimental details of the MLC and CE methods we conclude that CE seems to be slightly better than MLC in the determination of highly hydrophobic compounds in pharmaceuticals in terms of resolution and economy, taking into account that the limits of detection are not a handicap in pharmaceutical samples.