Simultaneous Determination of Docetaxel and Celecoxib in Porous Microparticles and Rat Plasma by Liquid-Liquid Extraction and HPLC with UV Detection: in vitro and in vivo Validation and Application

Abstract

Purpose: A simple, rapid, sensitive, and reliable HPLC method with UV detection was developed and validated for simultaneous quantitation of docetaxel and celecoxib and paclitaxel for dissolution characterization and pharmacokinetic studies. Methods: The HPLC assay was performed isocratically on a reversed-phase C18 μ-Bondapack column using a mobile phase of acetonitrile:water (45:55, v/v) at a flow rate of 1.2 mL/min, and the analytes were detected at 230 nm. Paclitaxel was used as an internal standard for analysis of plasma samples following simple liquid-liquid extraction with n-hexane:isoamyl alcohol (97:3). The method was validated for specificity, linearity, sensitivity, precision, accuracy, robustness, and in vitro-in vivo application. Results: The retention times for docetaxel, paclitaxel, and celecoxib were 10.94, 12.4, and 16.81 min, respectively. The standard curves covering 0.1-1 μg/mL and 0.05-4 μg/mL were linear using dissolution medium and rat plasma, respectively. The limit of quantitation of the method was 50 ng/mL using 100 μL of rat plasma sample and injection of 50 μL of the residue. Within- and between-day precision and accuracy did not exceed 16.86% and 12.10%, respectively. This validated method was successfully used to quantify docetaxel and celecoxib simultaneously in the release study of docetaxel-celecoxib -loaded porous microparticles and pharmacokinetics studies. The methods were found to be simple, specific, precise, accurate, and reproducible. In this study, paclitaxel was used as the internal standard while dexamethasone, flutamide, and budesonide proved suitable alternative as an internal standard. Conclusion: Since docetaxel and celecoxib could be co-administered for the treatment of a wide range of cancers such as non-small cell lung carcinoma, the developed method is particularly advantageous for routine therapeutic drug monitoring and pharmacokinetic studies of these drugs.

An Efficient HPLC-Uv Method for Determination of Tetrahydrocannabinol in Oil

“…The developed method achieved relatively low limits of [24]. HPLC coupled to MS increases sensitivity of the analysis, but the use of equipment requires skilled expertise to operate and is more expensive to run [9,25,26].…”

Development and validation of a new robust RP-HPLC method for simultaneous quantitation of insulin and pramlintide in non-invasive and smart glucose-responsive microparticles

“…Also, TFA has ion-pairing properties such that at low pHs (below the isoelectric pH of proteins), proteins are predominantly positively charged and are less hydrophobic to interact with the stationary phase, thus adding TFA to the mobile phase as an anionic counter ion, makes the protein more hydrophobic and interactive with the stationary phase, resulting in acceptable elution and retention time( 16 18 ). Moreover, the presence of TFA enhances the peak resolution and shapes as a result of minimizing the effect of metal impurities on peak shape in low-purity silica columns( 16 18 20 28 29 ). The volatility of ion-pairing reagents is an important issue because the risk of salt precipitation in the column is minimized (in comparison with phosphoric acid or buffers with acidic pH)( 16 17 18 19 20 ).…”

“…The analyte concentration that produced a signal-to-noise ratio of 3:1 was accepted as LOD. The LOQ was identified as the lowest concentration of the standard curve that could be quantified with acceptable accuracy, precision, and variability( 27 28 29 ).…”

“…The precision of the HPLC method was determined by intra-day and inter-day variations. Each level of precision was investigated by repeated analysis of standard solutions at concentrations ranging from 30 to 360 µg/mL for insulin and 1.5 to 12 µg/mL for pramlintide acetate in triplicate and three different media of mobile phase, loading and release media( 26 27 28 29 ). The percent coefficient of variance (% CV) or relative standard deviation indicating the precision of the assay, was determined using the following equation:…”

“…The robustness of the HPLC method was determined by analysis of samples under a variety of conditions such as small changes in the composition, pH, and the flow rate of the mobile phase, and the effects on peak parameters were studied( 26 27 28 29 ).…”