Spectrophotometric investigation of the chemical compatibility of the anticancer drugs irinotecan-HCl and epirubicin-HCl in the same infusion solution

Irinotecan and berberine co-delivery liposomes showed improved efficacy and reduced intestinal toxicity compared with Onivyde for pancreatic cancer

Onivyde is the first irinotecan (IRI) nanoliposome that could improve pharmacokinetics and tumor biodistribution of irinotecan. Although FDA approves Onivyde for the treatment of pancreatic cancer patients who are not effective for GEM, the gastrointestinal toxicity caused by Onivyde is still a problem to be solved in clinical application. Berberine (BER), an isoquinolone alkaloid extracted from several different plants, has been reported to exhibit beneficial effect in alleviating intestinal mucositis and generating synergistic anticancer effect in combination with cytotoxic drugs. However, its therapeutic effect is affected by the different pharmacokinetic behavior of two drugs. Therefore, we utilized triethylamine-sucrose octasulfate gradient to construct nanoliposomes for co-delivery of irinotecan and berberine, termed as lipBI. This co-delivery nanoliposomes remained the synergistic ratio in the body and improved tumor distribution of IRI and BER. The lipBI significantly inhibited tumor growth in the BXPC-3 pancreatic cancer model compared with Onivyde (p < 0.05) and reduced the gastrointestinal toxicity in mice caused by IRI. Overall, IRI/BER co-loaded liposomes possessed great potential in the treatment of pancreatic cancer.

Structural and photodynamic properties of the anti-cancer drug irinotecan in aqueous solutions of different pHs

This work reports on photophysical studies of the irinotecan (IRT) anti-cancer drug in water solutions of different acidities (pH = 1.11-9.46). We found that IRT co-exists as mono-cationic (C1), di-cationic (C2), or neutral (N) forms. The population of each prototropic species depends on the pH of the solution. At pH = 1.11-3.01, the C1 and C2 structures are stabilized. At pH = 7.00, the most populated species is C1, while at pH values larger than 9.46 the N form is the most stable species. In the 1.11-2.61 pH range, the C1* emission is efficiently quenched by protons to give rise to the emission from C2*. The dynamic quenching constant, KD, is ∼32 M-1. While the diffusion governs the rate of excited-state proton-transfer (ESPT) under these conditions, the reaction rate increases with the proton concentration. A two-step diffusive Debye-Smoluchowski model was applied at pH = 1.11-2.61 to describe the protonation of C1*. The ESPT time constants derived for C1* are 382 and 1720 ps at pH = 1.11 and 1.95, respectively. We found that one proton species is involved in the protonation of C1* to give C2*, in the analyzed acidic pH range. Under alkaline conditions (pH = 9.46), the N form is the most stable structure of IRT. These results indicate the influence of the pH of the medium on the structural and dynamical properties of IRT in water solution. They may help to provide a better understanding on the relationship between the structure and biological activity of IRT.

Validation of an LC-MS/MS method for the determination of epirubicin in human serum of patients undergoing drug eluting microsphere-transarterial chemoembolization (DEM-TACE)

Drug Eluting Microsphere-Transarterial Chemoembolization (DEM-TACE) is a new delivery system to administrate drugs in a controlled manner useful for application in the chemoembolization of colorectal cancer metastases to the liver. DEM-TACE is focused to obtain higher concentrations of the drug to the tumor with lower systemic concentrations than traditional cancer chemotherapy. Therefore a specific, precise and sensitive LC-ESI-MS/MS assay procedure was properly designed to detect and quantify epirubicin at the concentrations expected from a transarterial chemoembolization with microspheres. Serum samples were kept acidic (pH approximately of 3.5) and sample preparation consisted of a solid phase extraction (SPE) procedure with HLB OASIS cartridges using a methylene chloride/2-propanol/methanol mixture solution to recover epirubicin. The analyses consisted of reversed-phase high-performance liquid chromatography (rp-HPLC) coupled with tandem mass spectrometry (MS/MS). Accuracy, precision and matrix effect of this procedure were carried out by analyzing four quality control samples (QCs) on five separate days. The validation parameters were assessed by recovery studies of spiked serum samples. Recoveries were found to vary between 92 and 98% at the QC levels (5, 40, 80 and 150 microg/L) with relative standard deviation (RSD) always less than 3.7%. The limit of detection (LOD) was set at 1 microg/L. The developed procedure has been also applied to investigate the different capability of two types of commercially available microspheres to release epirubicin into the human circulatory system.