Contents lists available at ScienceDirect Microchemical Journal journal homepage: www.elsevier.com/locate/microc Quantifcation of rifampicin and rifabutin in plasma of tuberculosis patients by micellar liquid chromatography Maria Ángeles Goberna Bravo a , Abhilasha Durgbanshi b , Devasish Bose c , Pooja Mishra b , Jaume Albiol-Chiva d , Josep Esteve-Romero d , Juan Peris-Vicente a,⁎∗ a Department of Analytical Chemistry, Faculty of Chemistry, Universitat de València, Burjassot, 46100, Spain b Department of Chemistry, Doctor Harisingh Gour Vishwavidyalaya (A Central University), Madhya Pradesh, 470003, India c Department of Criminology and Forensic Science, Doctor Harisingh Gour Vishwavidyalaya (A Central University), Madhya Pradesh, 470003, India d Bioanalytical Chemistry, Department of Physical and Analytical Chemistry, ESTCE, Universitat Jaume I, Castelló, 12071, Spain ARTICLE INFO Keywords: Antituberculosis Drug Micellar Optimization Plasma Patients ABSTRACT A Micellar Liquid Chromatographic method is described to determine Rifampicin and Rifabutin in plasma from Tuberculosis patients. Samples were diluted in mobile phase and then directly injected, avoiding long and te- dious extraction steps. The analytes were resolved from the matrix without interferences from endogenous compounds using a mobile phase of sodium dodecyl sulfate 0.15 mol L-1–6%(v/v) 1-pentanol and phosphate bufer at pH 3, running at 1 mL min −1 through a C18 column at 25 °C. Detection was carried out by UV absorbance at 270 nm. Under these conditions, the fnal chromatographic analysis time was 22 min. The ana- lytical methodology was validated following the FDA 2018 Bioanalytical Method Validation Guidance for Industry. The response of the drugs in plasma was linear in the 0.05–5 μg/mL range, with r 2 > 0.9993. Trueness and precision were <14% for both substances. Carry over and matrix efects were negligible. Dilution integrity, robustness and stability were also investigated. Method was reliable, economic, eco-friendly, safe, easy-to- conduct, and with a high sample throughput, thus useful for routine analysis. Finally, the analytical method was used to determine both antituberculosis drugs in incurred plasma samples of Tuberculosis patients. 1. Introduction Tuberculosis remains a leading health issue worldwide and Rifampicin is the preferred frst-line drug for its treatment [1–3]. Al- though it is quite well tolerated in a usual dose regime, adverse efects could be developed including gastrointestinal reactions, exanthema, hepatotoxicity and immunological reactions, as thrombocytopenia, leukopenia, eosinophilia, hemolytic anemia, agranulocytosis, vasculitis, acute interstitial nephritis and septic shock [4,5]. While some adverse efects may be resolved with symptomatic treatment or spontaneously, others may require regimen changes because they are dose-dependent [6]. On the other hand, Rifabutin has activity against Mycobacterium tuberculosis similar to Rifampicin, in fact in most of the cases may be more efective [7]. Main diference between them is that rifabutin has lower incidence of severe adverse efects [8,10]. This point makes Ri- fabutin more attractive as a substitute in situations where Rifampicin might cause adverse efects or is not well tolerated. Furthermore, Ri- fampicin has more drug interactions than Rifabutin due to it is a potent inducer of the CYP450 system [11]. Due to this fact rifabutin has been used in patients coinfected with tuberculosis and HIV [12], trying to avoid possible difculties with drug interactions and avoiding the dis- ease spreading between susceptible people [13]. On the other hand, Rifabutin is the only frontline antituberculosis drug that has activity against an emergent disease as Mycobacterium Abcessus, an opportu- nistic pathogen causing dangerous pulmonary infections because are intrinsically multidrug resistant [14]. Rifampicin (Fig. 1; log Po/w = 2.7 [15]) is the principal anti- tuberculosis chemotherapy tool. However, Mycobacterium Tubercu- losis develop resistance to this drug with high frequency restricting the utility of its use for treatment. Tuberculosis strains classifed as multi- drug-resistant (MDR) are those resistant at least to the two most potent frst-line antituberculosis drugs, i.e. isoniazid and rifampicin [16–18]. The clinically signifcant resistance mechanism is mutation within a defned region of the rpoB gene, which encodes the target of RIF, the β subunit of bacterial RNA polymerase [19,20]. Most rifampicin-resistant Mycobacterium tuberculosis isolates are also resistant to rifapentine, while approximately 15-20% of them are susceptible to rifabutin [21]. Although that confers a signifcant advantage, Rifabutin (Fig. 1; log Po/ https://doi.org/10.1016/j.microc.2020.104865 Received 3 March 2020; Received in revised form 19 March 2020; Accepted 23 March 2020 ⁎ Corresponding author. E-mail address: juan.peris@uv.es (J. Peris-Vicente). Microchemical Journal 157 (2020) 104865 Available online 24 April 2020 0026-265X/ © 2020 Elsevier B.V. All rights reserved. T