Simultaneous determination of albendazole and its major active metabolite in human plasma using a sensitive and specific liquid chromatographic–tandem mass spectrometric method

Factors associated with variation in single-dose albendazole pharmacokinetics: A systematic review and modelling analysis

Background

Albendazole is an orally administered anti-parasitic medication with widespread usage in a variety of both programmatic and clinical contexts. Previous work has shown that the drug’s pharmacologically active metabolite, albendazole sulfoxide, is characterised by substantial inter-individual pharmacokinetic variation. This variation might have implications for the efficacy of albendazole treatment, but current understanding of the factors associated with this variation remains incomplete.

Methodology/Principal findings

We carried out a systematic review to identify references containing temporally disaggregated data on the plasma concentration of albendazole and/or (its pharmacologically-active metabolite) albendazole sulfoxide following a single oral dose. These data were then integrated into a mathematical modelling framework to infer albendazole sulfoxide pharmacokinetic parameters and relate them to characteristics of the groups being treated. These characteristics included age, weight, sex, dosage, infection status, and whether patients had received a fatty meal prior to treatment or other drugs alongside albendazole. Our results highlight a number of factors systematically associated with albendazole sulfoxide pharmacokinetic variation including age, existing parasitic infection and receipt of a fatty meal. Age was significantly associated with variation in albendazole sulfoxide systemic availability and peak plasma concentration achieved; as well as the clearance rate (related to the half-life) after adjusting for variation in dosage due to differences in body weight between children and adults. Receipt of a fatty meal prior to treatment was associated with increased albendazole sulfoxide systemic availability (and by extension, peak plasma concentration and total albendazole sulfoxide exposure following the dose). Parasitic infection (particularly echinococcosis) was associated with altered pharmacokinetic parameters, with infected populations displaying distinct characteristics to uninfected ones.

Conclusions/Significance

These results highlight the extensive inter-individual variation that characterises albendazole sulfoxide pharmacokinetics and provide insight into some of the factors associated with this variation.

HPLC Determination of Imidazoles with Variant Anti-Infective Activity in Their Dosage Forms and Human Plasma

A suitable HPLC method has been selected and validated for rapid simultaneous separation and determination of four imidazole anti-infective drugs, secnidazole, omeprazole, albendazole, and fenbendazole, in their final dosage forms, in addition to human plasma within 5 min. The method suitability was derived from the superiority of using the environmentally benign solvent, methanol over acetonitrile as a mobile phase component in respect of safety issues and migration times. Separation of the four anti-infective drugs was performed on a Thermo Scientific^® BDS Hypersil C₈ column (5 µm, 2.50 × 4.60 mm) using a mobile phase consist of MeOH: 0.025 M KH₂PO₄ (70:30, v/v) adjusted to pH 3.20 with ortho-phosphoric acid at room temperature. The flow rate was 1.00 mL/min and maximum absorption was measured with UV detector set at 300 nm. Limits of detection were reported to be 0.41, 0.13, 0.18, and 0.15 µg/mL for secnidazole, omeprazole, albendazole, and fenbendazole, respectively, showing a high degree of the method sensitivity. The method of analysis was validated according to Food and Drug Administration (FDA)guidelines for the determination of the drugs, either in their dosage forms with highly precise recoveries, or clinically in human plasma, especially regarding pharmacokinetic and bioequivalence studies.

Assessment of the Performance of Solid Phase Extraction Based on Pipette Tip Employing a Hybrid Molecularly Imprinted Polymer as an Adsorbent for Enantioselective Determination of Albendazole Sulfoxide

Herein, an organic–inorganic hybrid molecularly imprinted polymer (MIP) was successfully synthesized with albendazole sulfoxide (ABZSO) as a template and 3-(trimethoxysilyl)propyl methacrylate, a bifunctional group compound, as a single cross-linking agent. In this study, a simple method using HPLC–DAD was developed for the determination of ABZSO enantiomers in human urine using pipette tip-based molecularly imprinted polymer solid phase extraction (PT–MIP–SPE). Enantioseparation with satisfactory retention times (5.17 and 7.09 min), acceptable theoretical plates (N = 4,535 and 5,091) and strong resolution (Rs = 5.45) was performed with an Agilent® Eclipse Plus C18 (100 mm × 4.6 mm, 3.5 μm) coupled with a Chiralpak® IA column (100 mm × 4.6 mm, 3 μm), a mixture with ethanol:water (50:50, v/v) as the mobile phase, temperature at 40°C, flow rate at 0.9 mL min−1 and λ = 230 nm. Thereafter, certain parameters affecting the PT–MIP–SPE were investigated in detail and the better conditions were: 300 μL of water as washing solvent, 500 μL of ethanol:acetic acid (9:1, v/v) as eluting solvent, 20 mg of MIP, 500 μL of human urine at pH 9 and no addition of NaCl. Recoveries/relative standard deviation (RSD%) for (R)-(+)-ABZSO and (S)-(−)-ABZSO were 78.2 ± 0.2% and 69.7 ± 1.7%, respectively.

Pharmacokinetics of Albendazole, Albendazole Sulfoxide, and Albendazole Sulfone Determined from Plasma, Blood, Dried-Blood Spots, and Mitra Samples of Hookworm-Infected Adolescents

Albendazole is an effective anthelmintic intensively used for decades. However, profound pharmacokinetic (PK) characterization is missing in children, the population mostly affected by helminth infections. Blood microsampling would facilitate PK studies in pediatric populations but has not been applied to quantify albendazole's disposition. Quantification methods were developed and validated using liquid chromatography-tandem mass spectrometry to analyze albendazole and its metabolites albendazole sulfoxide and albendazole sulfone in wet samples (plasma and blood) and blood microsamples (dried-blood spots [DBS]; Mitra). The use of DBS was limited by a matrix effect and poor recovery, but the extraction efficiency was constant throughout the concentration range. Hookworm-infected adolescents were venous and capillary blood sampled posttreatment with 400 mg albendazole and 25 mg/kg oxantel pamoate. Similar half-life (t _1/2 = ∼1.5 h), time to reach the maximum concentration (t _max = ∼2 h), and maximum concentration (C _max = 12.5 to 26.5 ng/ml) of albendazole were observed in the four matrices. The metabolites reached C _max after ∼4 h with a t _1/2 of ca. 7 to 8 h. A statistically significant difference in albendazole sulfone's t _1/2 as determined by using DBS and wet samples was detected. C _max of albendazole sulfoxide (288 to 380 ng/ml) did not differ among the matrices, but higher C _max of albendazole sulfone were obtained in the two microsampling devices (22 ng/ml) versus the wet matrices (14 ng/ml). In conclusion, time-concentration profiles and PK results of the four matrices were similar, and the direct comparison of the two microsampling devices indicates that Mitra extraction was more robust during validation and can be recommended for future albendazole PK studies.

Liquid chromatography--tandem mass spectrometry method for simultaneous determination of albendazole and albendazole sulfoxide in human plasma for bioequivalence studies

An improved high performance liquid chromatography--tandem mass spectrometry (LC–MS/MS) method has been developed for sensitive and rapid determination of albendazole (ABZ) and its active metabolite, albendazole sulfoxide (ABZSO), in the positive ionization mode. The method utilized solid phase extraction (SPE) for sample preparation of the analytes and their deuterated internal standards (ISs) from 100 µL human plasma. The chromatography was carried out on Hypurity C₁₈ column using acetonitrile-2.0 mM ammonium acetate, pH 5.0 (80:20, v/v) as the mobile phase. The assay exhibited a linear response over the concentration range of 0.200–50.0 ng/mL for ABZ and 3.00–600 ng/mL for ABZSO. The recoveries of the analytes and ISs ranged from 86.03%–89.66% and 89.85%–98.94%, respectively. Matrix effect, expressed as IS-normalized matrix factors, ranged from 0.985 to 1.042 for the both analytes. The method was successfully applied for two separate studies in healthy subjects using single dose of 400 mg conventional tablets and 400 mg chewable ABZ tablets, respectively.

Rationale for the coadministration of albendazole and ivermectin to humans for malaria parasite transmission control

Recently there have been calls for the eradication of malaria and the elimination of soil-transmitted helminths (STHs). Malaria and STHs overlap in distribution, and STH infections are associated with increased risk for malaria. Indeed, there is evidence that suggests that STH infection may facilitate malaria transmission. Malaria and STH coinfection may exacerbate anemia, especially in pregnant women, leading to worsened child development and more adverse pregnancy outcomes than these diseases would cause on their own. Ivermectin mass drug administration (MDA) to humans for malaria parasite transmission suppression is being investigated as a potential malaria elimination tool. Adding albendazole to ivermectin MDAs would maximize effects against STHs. A proactive, integrated control platform that targets malaria and STHs would be extremely cost-effective and simultaneously reduce human suffering caused by multiple diseases. This paper outlines the benefits of adding albendazole to ivermectin MDAs for malaria parasite transmission suppression.

Current bioanalytical methods for pharmacokinetic studies of drugs used in neglected tropical diseases

Neglected tropical diseases are conditions directly associated to poverty and affect millions of people in tropical areas. Considering the necessity of pharmacokinetic and therapeutic drug monitoring studies to assess the disposition of agents clinically employed in the treatment of these diseases, especially in the involved population, this article will overview the current bioanalytical methods developed in the last 10 years, particularly those fully validated and using standard techniques, such as chromatographic procedures combined or not with mass spectrometry. The characteristics of each assay reported will be summarized and critically discussed. Furthermore, emphasis will also be given to the pros and cons in order to highlight the application of each method, especially in routine laboratories.

Study on the interaction between albendazole and eosin Y by fluorescence, resonance Rayleigh scattering and frequency doubling scattering spectra and their analytical applications

In pH 3.25-3.35 Britton-Robinson (BR) buffer solution, albendazole (ABZ) could react with eosin Y (EY) to form a 1:1 ion-association complex, which not only results in the quenching of fluorescence, but also resulted in the great enhancement of resonance Rayleigh scattering (RRS) and frequency doubling scattering (FDS). Furthermore, a new RRS spectrum will appear, and the maximum RRS wavelength was located at about 356nm. The detection limit for ABZ were 21.51ng mL(-)(1) for the fluorophotometry, 6.93ng mL(-)(1) for the RRS method and 12.89ng mL(-)(1) for the FDS method. Among them, the RRS method had the highest sensitivity. The experimental conditions were optimized and effects of coexisting substances were evaluated. Meanwhile, the influences of coexisting substances were tested. The methods have been successfully applied to the determination of ABZ in capsules and human urine samples. The composition and structure of the ion-association complex and the reaction mechanism were discussed.

Highly sensitive LC-MS/MS-ESI method for simultaneous quantitation of albendazole and ricobendazole in rat plasma and its application to a rat pharmacokinetic study

A highly sensitive and specific LC-MS/MS-ESI method was developed for simultaneous quantification of albenadazole (ABZ) and ricobendazole (RBZ) in rat plasma (50 μL) using phenacetin as an internal standard (IS). Simple protein precipitation was used to extract ABZ and RBZ from rat plasma. The chromatographic resolution of ABZ, RBZ and IS was achieved with a mobile phase consisting of 5 m m ammonium acetate (pH 6) and acetonitrile (20:80, v/v) at a flow rate of 1 mL/min on a Chromolith RP-18e column. The total chromatographic run time was 3.5 min and the elution of ABZ, RBZ and IS occurred at 1.66, 1.50 and 1.59 min, respectively. A linear response function was established for the ranges of concentrations 2.01-2007 and 6.02-6020 ng/mL for ABZ and RBZ, respectively. The intra- and inter-day precision values for ABZ and RBZ met the acceptance as per FDA guidelines. ABZ and RBZ were stable in battery of stability studies, viz. bench-top, auto-sampler and freeze-thaw cycles. The developed assay was applied to a pharmacokinetic study in rats.

Simultaneous determination of albendazole metabolites, praziquantel and its metabolite in plasma by high-performance liquid chromatography–electrospray mass spectrometry

The analysis of albendazole sulfoxide, albendazole sulfone, praziquantel and trans-4-hydroxypraziquantel in plasma was carried out by high-performance liquid chromatography-mass spectrometry ((LC-MS-MS). The plasma samples were prepared by liquid-liquid extraction using dichloromethane as extracting solvent. The partial HPLC resolution of drug and metabolites was obtained using a cyanopropyl column and a mobile phase consisting of methanol:water (3:7, v/v) plus 0.5% of acetic acid, at a flow rate of 1.0 mL/min. Multi reaction monitoring detection was performed by electrospray ionization in the positive ion mode, conferring additional selectivity to the method. Method validation showed relative standard deviation (precision) and relative errors (accuracy) lower than 15% for all analytes evaluated. The quantification limit was 5 ng/mL and the linear range was 5-2500 ng/mL for all analytes. The method was used for the determination of drug and metabolites in swine plasma samples and proved to be suitable for pharmacokinetic studies.