Determination of irinotecan and its metabolite SN-38 in rabbit plasma and tumors using a validated method of tandem mass spectrometry coupled with liquid chromatography

Development and validation of an UPLC-MS/MS method for the determination of irinotecan (CPT-11), SN-38 and SN-38 glucuronide in human plasma and peritoneal tumor tissue from patients with peritoneal carcinomatosis

Irinotecan (CPT-11), an antineoplastic drug, is used for the treatment of colorectal and pancreatic cancer due to its topoisomerase I inhibitory activity. CPT-11 is a prodrug which is converted to its active metabolite SN-38 by carboxylesterases. SN-38 is further metabolized to its inactive metabolite SN-38 glucuronide. When evaluating the pharmacokinetic properties of CPT-11 and its metabolites, it is important to accurately assess the concentrations in both plasma as well as tumor tissues. Therefore, the aim of the current study was to develop and validate a robust and sensitive ultra-high performance liquid chromatography-tandem mass spectrometry method to quantify the concentration of CPT-11 and its metabolites (SN-38 and SN-38 glucuronide) in human plasma and peritoneal tumor tissue. The sample preparation of plasma and tumor tissue consisted of protein precipitation and enzymatic digestion/liquid-liquid extraction, respectively. Chromatographic separation was achieved with an Acquity UPLC BEH C18 column combined with a VanGuard pre-column. The mobile phases consisted of water +0.1 % formic acid (mobile phase A) and acetonitrile +0.1 % formic acid (mobile phase B). Mass analysis was performed using a Xevo TQS tandem mass spectrometer in the positive electrospray ionization mode. Method validation was successfully performed by assessing linearity, precision and accuracy, lower limit of quantification, carry over, selectivity, matrix effect and stability according to the following guidelines: "Committee for Medicinal Products for Human use, Guideline on Bioanalytical Method Validation". A cross-validation of the developed method was performed in a pilot pharmacokinetic study, demonstrating the usefulness of the current method to quantify CPT-11 and its metabolites in the different matrices.

Evaluation on the Metabolic Activity of Two Carboxylesterase Isozymes in Mouse Liver Microsomes by a LC-MS/MS Method

An applicable method for the precise measurement of major carboxylesterase (CESs) activity in liver still limited. Clopidogrel and irinotecan are specific substrates for CES1 and CES2, respectively. Clopidogrel is metabolized to the inactive metabolite clopidogrel carboxylate (CCAM) by CES1. Irinotecan is metabolized to the active metabolite 7-ethyl-10-hydroxycamptothecin (SN-38) by CES2. In the present study, the LC-MS/MS method for the determination of CCAM and SN-38 were separately developed to characterize the metabolic activities of CES1 and CES2 in mouse liver microsomal. CCAM was separated on a Ecosil ODS column with an isocratic mobile phase consisted of 5 mmol/L ammonium formate and 0.1% formic acid in water and acetonitrile (15:85, V:V) at a flow rate of 0.4mL/min. SN-38 was separated on a Waters symmetry C18 column with an gradient mobile phase consisted of 5 mmol/L ammonium formate and 0.1% formic acid in water and acetonitrile at a flow rate of 0.3 mL/min. Calibration curves were linear within the concentration range of 100-20,000 ng/mL for CCAM and 1-200 ng/mL for SN-38. The results of method showed excellent accuracy and precision. The recovery rate, matrix effect and stability inspection results were within the acceptance criteria. The optimized incubation conditions were as follows: protein concentration of microsomes were all 0.1 mg/mL, incubation time was 60 min for clopidogrel and 30 min for irinotecan, respectively. This method was sensitive and applicable for the determination of the activity of CESs in the mouse liver microsomes.

Identification of the bioactive components of Banxia Xiexin Decoction that protect against CPT-11-induced intestinal toxicity via UPLC-based spectrum-effect relationship analyses

ETHNOPHARMACOLOGICAL RELEVANCE

Irinotecan (CPT-11) is a valuable chemotherapeutic compound, but its use is associated with severe diarrhea in some patients. The CPT-11 prodrug is converted into the active 7-ethyl-10-hydroxycamptothecin (SN-38) metabolite, which can then be retained for extended periods in the intestine, leading to the onset of diarrhea and related symptoms. Banxia Xiexin Decoction (BXD) is commonly employed for the treatment of gastroenteritis in traditional Chinese medicine (TCM), and in clinical settings, it is used to prevent diarrhea in patients undergoing CPT-11 treatment. To date, however, there have been no studies specifically examining which components of BXD can alleviate the gastrointestinal symptoms associated with CPT-11 administration.

AIM

This study aimed to identify the main herbal components of BXD associated with protection against CPT-11-induced intestinal toxicity in a murine model system.

MATERIALS AND METHODS

SN-38 levels were measured by UPLC-ESI-MS/MS in samples collected from mice subjected to CPT-11-induced diarrhea that had been administered BXD or different components thereof. Pearson correlation and Grey relational analyses were then used to explore spectrum-effect relationships between reductions in intestinal SN-38 levels and specific chemical fingerprints in samples from mice administered particular combinations of BXD component herbs.

RESULTS

We found that different herbal combinations were associated with significant differences in intestinal SN-38 reductions in treated mice. Our spectrum-effect analysis revealed that BXD components including chrysin 6-C-arabinoside-8-C-glucoside, coptisine, hydroxyl oroxylin A 7-O-glucuronide (hydroxyl wogonoside), baicalin, an isomer of 5,6,7-trihydroxyl-flavanone-7-O-glucuronide, berberine, palmatine, and chrysin-7-O-glucuronide were all directly linked with reductions in intestinal SN-38 levels. We therefore speculate that these compounds are the primary bioactive components of BXD, suggesting that they offer protection against CPT-11-induced diarrhea.

CONCLUSION

By utilizing UPLC to analyze SN-38 levels in mice treated with a variety of herbal combinations, we were able to effectively explore BXD spectrum-effect relationships and to thereby establish the components of this medicinal preparation that were bioactive and capable of preventing CPT-11-induced diarrhea in mice. This and similar spectrum-effect studies represent a robust means of exploring the mechanistic basis for the pharmacological activity of TCM preparations.

Intratumoral Injection Administration of Irinotecan-Loaded Microspheres: In Vitro and In Vivo Evaluation

To reduce the toxic and side effects of intravenous chemotherapeutic drugs on the tumor-patients, the aims of this study were to design and study intratumor-administrated irinotecan-loaded PLGA microspheres (CPT-11-PLGA-MS) in vitro and in vivo according to the structure characteristics of CPT-11. PLGA microspheres containing irinotecan were prepared by emulsion solvent evaporation method and evaluated in terms of their morphology, particle size analysis, in vitro drug release, drug retention and leakage studies in vivo, and pharmacodynamics studies. The CPT-11-PLGA-MS were spherical with mean size of 9.29 ± 0.02 μm, and average encapsulation efficiency were measured of 77.97 ± 1.26% along with the average drug loading of 7.08 ± 0.11%. DSC results indicated that the drug existed in the phase of uncrystallization in the microspheres. The formulation of CPT-11-PLGA-MS could prolong the in vitro drug release to 16 days following Weibull equation. In CPT-11-PLGA-MS after intratumor injection administration was significantly improved. The results demonstrated that the slow-sustained release of CPT-11-PLGA-MS in tumor tissue after intratumor injection of microspheres can reduce the drug leakage to the circulation system, maintain the drug retention, and improve the therapeutic effect, which could become a promising drug delivery system for CPT-11 and could maintain the most effective concentration at the target site to maximum limit.

Pharmacokinetics and tissue distribution study of 10-methoxycamptothecin in rats following intragastric administration

Natural bioactive derivatives of camptothecin (CPT), 10-methoxycamptothecin (MCPT) and 10-hydroxycamptothecin (HCPT) have been confirmed to possess high antitumor activities. MCPT could be metabolized to HCPT in vivo. The HPLC method for the quantification of MCPT and HCPT was established and validated, and the pharmacokinetics and the tissue distribution of MCPT in rats after i.v. administration have been well carried out in our previous studies. To improve the further understanding of the in vivo behavior of MCPT, a rapid and sensitive UPLC-MS/MS method was developed and validated for the quantification of MCPT and HCPT in plasma and tissue samples, and the pharmacokinetics and tissue distribution as well as the bioavailability of MCPT after i.g. were also illustrated. The results showed that MCPT could be highly converted to its active metabolite HCPT in plasma with the AUC_0-∞ value of (185.28±61.73) ngh/mL and (717.25±165.67) ngh/mL for MCPT and HCPT, respectively. Meanwhile, MCPT and HCPT were rapidly absorbed and diffused into all the tested tissues (heart, liver, spleen, lung, kidney and brain) after i.g. administration. Similar with the results after i.v. administration of MCPT, MCPT concentration in lung tissue was also extremely higher than in other tested tissues, which implied that MCPT might have a great potential for the treatment of lung cancer.

Antineoplastic drugs and their analysis: a state of the art review

We provide an overview of the analytical methods available for the quantification of antineoplastic drugs in pharmaceutical formulations, biological and environmental samples.

Development and validation of an UPLC-MS/MS method for the quantification of irinotecan, SN-38 and SN-38 glucuronide in plasma, urine, feces, liver and kidney: Application to a pharmacokinetic study of irinotecan in rats

The objective of this research is to develop and validate a sensitive and reproducible UPLC-MS/MS method to quantify irinotecan, its active metabolite SN-38 and SN-38 glucuronide (phase II metabolite of SN-38) simultaneously in different bio-matrices (plasma, urine, feces), tissues (liver and kidney) and to use the method to investigate its pharmacokinetic behavior in rats. Irinotecan, SN-38 and SN-38 glucuronide has been resolved and separated by C18 column using acetonitrile and 0.1% formic acid in water used as the mobile phases. Triple quadruple mass spectrometer using multiple reaction monitoring (MRM) with positive scan mode were employed to perform mass analysis. The results showed that the linear response range of irinotecan and SN-38 in plasma, feces, liver and kidney is 4.88-10000 nM, 39-5000 nM, 48.8-6250 nM and 48.8-6250 nM, respectively (R(2)>0.99). In case of SN-38 glucuronide, the standard curves were linear in the concentration range of 6.25-2000 nM, 4.88-1250 nM, 9.8-1250 nM and 9.8-1250 nM in plasma, feces, liver and kidney homogenates, respectively. The lower limit of detection (LLOD) of irinotecan, SN-38 and SN-38 glucuronide was determined to be less than 25 nM in all bio-matrices as well as tissue homogenates. Recoveries of irinotecan, SN-38 and SN-38 glucuronide at three different concentrations (low, medium and high) were not less than 85% at three different concentrations in plasma and feces. The percentage matrix factors in different bio-matrices and tissues were within 20%. The UPLC-MS/MS method was validated with intra-day and inter-day precision of less than 15% in plasma, feces, liver and kidney. Owing to the high sensitivity of this method, only 20 μl of plasma, urine and homogenates of liver, kidney and feces is needed. The validated method has been successfully employed for pharmacokinetic evaluation of irinotecan in male wistar rats to quantify irinotecan, SN-38 and SN-38 glucuronide in plasma, feces, and urine samples.

Integrated microfluidic system for cell co-culture and simulation of drug metabolism

We present a microfluidic integrator for cell cocultivation and simulation of pharmaceutical kinetic processes of oral drugs including intestinal absorption, liver metabolism, and anticancer activity.