Microextraction by packed sorbent and high performance liquid chromatography for simultaneous determination of lumefantrine and desbutyl-lumefantrine in plasma samples

Microextraction by packed sorbent and high-performance liquid chromatography for determination of benznidazole in human plasma

Benznidazole is the main drug used in Chagas disease and its determination in plasma samples is useful in several situations. Hence, robust and accurate bioanalytical methods are needed. In this context, sample preparation deserves special attention, as it is the most error-prone, labor-intensive and time-consuming step. Microextraction by packed sorbent (MEPS) is a miniaturized technique, developed to minimize the use of hazardous solvents and sample amount. In this context, this study aimed to develop and validate a MEPS coupled to high performance liquid chromatography method for the analysis of benznidazole in human plasma. MEPS optimization was performed by a 2⁴ full factorial experimental design, which resulted in about 25 % of recovery. The best condition was achieved when 500 µL of plasma,10 draw-eject cycles, sample volume drawn of 100 µL, and desorption with three times of 50 µL of acetonitrile were used. The chromatographic separation was performed with a C18 (150 × 4.5 mm, 5 µm) column. The mobile phase was composed of water:acetonitrile (60:40) at a flow rate of 1.0 mL min^-1. The developed method was validated and proved to be selective, precise, accurate, robust and linear in the range from 0.5 to 6.0 µg mL^-1. The method was applied to three healthy volunteers that made use of benznidazole tablets and showed to be adequate to assess this drug in plasma samples.

Determination of antimalarial drugs in pharmaceutical formulations and human blood by liquid chromatography: a review

Malaria is a life-threatening disease being treated by oral medication. This is the best treatment to reduce morbidity and mortality, prevent disease progression to the most severe form, lower the transmission of the disease and hinder the appearance of strains resistant to antimalarials. According to the World Health Organization, the most common antimalarial drugs are chloroquine, primaquine, mefloquine, lumefantrine, artemether, and artesunate in single dosage forms or fixed-dose combination. Within this context, the present review aims to show the evolution of different analytical methods that have been applied to the determination of these antimalarial drugs in pharmaceutical formulations and human blood by liquid chromatography in the last 10 years, along with statistical analyses of the methods.

Recent applications of microextraction sample preparation techniques in biological samples analysis

Analysis of biological samples is affected by interfering substances with chemical properties similar to those of the target analytes, such as drugs. Biological samples such as whole blood, plasma, serum, urine and saliva must be properly processed for separation, purification, enrichment and chemical modification to meet the requirements of the analytical instruments. This causes the sample preparation stage to be of undeniable importance in the analysis of such samples through methods such as microextraction techniques. The scope of this review will cover a comprehensive summary of available literature data on microextraction techniques playing a key role for analytical purposes, methods of their implementation in common biological samples, and finally, the most recent examples of application of microextraction techniques in preconcentration of analytes from urine, blood and saliva samples. The objectives and merits of each microextration technique are carefully described in detail with respect to the nature of the biological samples. This review presents the most recent and innovative work published on microextraction application in common biological samples, mostly focused on original studies reported from 2017 to date. The main sections of this review comprise an introduction to the microextraction techniques supported by recent application studies involving quantitative and qualitative results and summaries of the most significant, recently published applications of microextracion methods in biological samples. This article considers recent applications of several microextraction techniques in the field of sample preparation for biological samples including urine, blood and saliva, with consideration for extraction techniques, sample preparation and instrumental detection systems.