Simple, Rapid and Validated LC Determination of Lopinavir in Rat Plasma and Its Application in Pharmacokinetic Studies

Abstract

Lopinavir is a new specific and potent HIV-1 protease inhibitor. A simple and rapid Reverse Phase High-Performance Liquid Chromatographic method using UV detection was developed and validated for the analysis of lopinavir in rat plasma under isocratic conditions. The method involves a single step protein precipitation technique. The detector response was linear over the concentration range of 250 to 4000 ng mL −1. High recovery ranging from 97.5 to 101.2 percent was obtained which precludes the use of internal standard. The developed method was validated as per standard guidelines. Validation of the developed method demonstrated accuracy, precision and selectivity of the proposed method. The drug was found to be stable under various processing and storage conditions. This rapid and cost-effective method was successfully applied in the estimation of lopinavir and determination of various pharmacokinetic parameters during post intravenous bolus administration of the drug in rats. The developed method can be suitably employed in preclinical pharmacokinetic evaluation of new formulations designed to improve the bioavailability of lopinavir.

A hybrid design to optimize preparation of lopinavir loaded solid lipid nanoparticles and comparative pharmacokinetic evaluation with marketed lopinavir/ritonavir coformulation

“…Post‐dosing, samples were collected at following time points: 0.17, 0.25, 0.5, 1, 2, 3, 4, 6, 8 and 12 h. These samples were further harvested for plasma by centrifuging at 4°C for 10 min at 650 g and then stored at −70°C until further analysis. A validated HPLC method, previously reported[23] from our lab for estimation of LPV in rat plasma matrix, was used to analyze the samples.…”

Development and validation of a cost‐effective and sensitive bioanalytical HPLC‐UV method for determination of lopinavir in rat and human plasma

“…All QC samples (LQC, MQC and HQC) were considered to be stable under different realistic storage conditions, with the values of accuracy (RE) and precision (RSD) in the acceptable range (RE within ±15%, RSD ≤ 15%). Very limited LPV stability data in rat plasma have been reported in previous studies and only included freeze–thaw, short‐term and autosampler stability experiments (Vats et al, 2011). To the best of our knowledge, this is the first report that covers full validation and stability of LPV in rat plasma according to FDA guidelines (Food and Drug Administration, 2018).…”

“…The individual plasma concentration–time profiles of LPV in three rats are shown in Figure 2, and mean plasma pharmacokinetic parameters obtained using non‐compartmental analysis are presented in Table 4. Limited number of preclinical pharmacokinetic studies following single intravenous bolus of LPV in rats have been reported (Kumar et al, 2004; Vats et al, 2011). The elimination t 1/2 (0.49 ± 0.01 hr) obtained in this study is shorter than the t 1/2 previously reported (0.82 ± 0.03 hr) using the HPLC‐UV method for the detection of LPV (Vats et al, 2011).…”

“…Limited number of preclinical pharmacokinetic studies following single intravenous bolus of LPV in rats have been reported (Kumar et al, 2004; Vats et al, 2011). The elimination t 1/2 (0.49 ± 0.01 hr) obtained in this study is shorter than the t 1/2 previously reported (0.82 ± 0.03 hr) using the HPLC‐UV method for the detection of LPV (Vats et al, 2011). The lower sensitivity of the previously reported method (LLOQ = 250 ng/mL) limited sampling up to 3 hr, which resulted in sampling duration of less than four times the elimination t 1/2 .…”

“…To date, a large number of bioanalytical methods were developed for the determination of LPV with other antiretroviral drugs in plasma using HPLC with UV detection (Faux, Venisse, Olivier, & Bouquet, 2001; Justesen, Pedersen, & Klitgaard, 2003; Notari et al, 2006; Poirier, Robidou, & Jaillon, 2005; Ray, Pang, & Carey, 2002; Rezk, Tidwell, & Kashuba, 2004; Weller, Brundage, Balfour, & Vezina, 2007) or LC–tandem mass spectrometry (LC–MS/MS; Else et al, 2010; Estrela, Ribeiro, Seixas, & Suarez‐Kurtz, 2008; Martin et al, 2009; Temghare, Shetye, & Joshi, 2009). However, previously reported bioanalytical methods for determination of LPV utilizing the HPLC‐UV methodology are not sensitive enough when low‐volume samples are used (Vats, Murthy, & Ravi, 2011). By contrast, the LC–MS/MS methodology does provide sufficient sensitivity, but is too expensive for efficient TDM or preclinical research in resource‐limited countries.…”