Spectrofluorimetric determination of thioridazine and flupentixol in dosage forms; application to content uniformity test

A reliable, sensitive, cheap and non‐extractive spectrofluorimetric method has been developed and validated for determination of thioridazine and flupentixol based on ternary complex formation with eosin and lead(II) in the presence of methylcellulose as surfactant at pH 3.2. Under the optimum conditions, the quantitative quenching effect of investigated drugs on the native fluorescence of eosin has been investigated. The quenching of the eosin fluorescence was measured at 517 nm after excitation at 462 nm. The different experimental parameters affecting the development and stability of the reaction products were carefully studied and optimized, and the results were satisfactory. The calibration plots were constructed over the range of 0.5–3.0 µg mL^?1. The developed method was successfully applied for determination of investigated drugs in commercial tablets without interference from common excipients. It was further applied for content uniformity testing of flupentixol in its tablets. Statistical comparisons of the results with those of the reference methods revealed excellent agreement and indicated no significant difference in accuracy and precision. Copyright © 2015 John Wiley & Sons, Ltd.     

Racemization and degradation of thioridazine and thioridazine 2-sulfone in human plasma and aqueous solutions

We present two methods for the enantioselective analysis of thioridazine (THD) and thioridazine 2-sulfone (THD 2-SO(2)) in human plasma based on liquid-liquid extraction with diethyl ether and chiral resolution of the enantiomers on Chiralpak AD and Chiralcel OD-H columns, respectively. After validation, the methods were used to study the degradation and racemization of both drug and metabolite. Our results showed that both enantiomers of THD and THD 2-SO(2) were stable at varying temperatures, pH, and ionic strengths; however, solubility problems for THD and THD 2-SO(2) enantiomers were observed, mainly at pH 8.5. The influence of light on the stability of the THD and THD 2-SO(2) enantiomers was also studied. Degradation of the THD enantiomers was observed under UV light (254 and 366 nm) while THD 2-SO(2) enantiomers were stable at these wavelengths and also when exposed to visible light.     

DRUGSURV: a resource for repositioning of approved and experimental drugs in oncology based on patient survival information

The use of existing drugs for new therapeutic applications, commonly referred to as drug repositioning, is a way for fast and cost-efficient drug discovery. Drug repositioning in oncology is commonly initiated by in vitro experimental evidence that a drug exhibits anticancer cytotoxicity. Any independent verification that the observed effects in vitro may be valid in a clinical setting, and that the drug could potentially affect patient survival in vivo is of paramount importance. Despite considerable recent efforts in computational drug repositioning, none of the studies have considered patient survival information in modelling the potential of existing/new drugs in the management of cancer. Therefore, we have developed DRUGSURV; this is the first computational tool to estimate the potential effects of a drug using patient survival information derived from clinical cancer expression data sets. DRUGSURV provides statistical evidence that a drug can affect survival outcome in particular clinical conditions to justify further investigation of the drug anticancer potential and to guide clinical trial design. DRUGSURV covers both approved drugs (∼1700) as well as experimental drugs (∼5000) and is freely available at http://www.bioprofiling.de/drugsurv.     

Antipsychotic agent thioridazine sensitizes renal carcinoma Caki cells to TRAIL-induced apoptosis through reactive oxygen species-mediated inhibition of Akt signaling and downregulation of Mcl-1 and c-FLIP(L)

Thioridazine has been known as an antipsychotic agent, but it also has anticancer activity. However, the effect of thioridazine on tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) sensitization has not yet been studied. Here, we investigated the ability of thioridazine to sensitize TRAIL-mediated apoptosis. Combined treatment with thioridazine and TRAIL markedly induced apoptosis in various human carcinoma cells, including renal carcinoma (Caki, ACHN, and A498), breast carcinoma (MDA-MB231), and glioma (U251MG) cells, but not in normal mouse kidney cells (TMCK-1) and human normal mesangial cells. We found that thioridazine downregulated c-FLIP(L) and Mcl-1 expression at the post-translational level via an increase in proteasome activity. The overexpression of c-FLIP(L) and Mcl-1 overcame thioridazine plus TRAIL-induced apoptosis. We further observed that thioridazine inhibited the Akt signaling pathway. In contrast, although other phosphatidylinositol-3-kinase/Akt inhibitors ({"type":"entrez-nucleotide","attrs":{"text":"LY294002","term_id":"1257998346","term_text":"LY294002"}}LY294002 and wortmannin) sensitized TRAIL-mediated apoptosis, c-FLIP(L) and Mcl-1 expressions were not altered. Furthermore, thioridazine increased the production of reactive oxygen species (ROS) in Caki cells, and ROS scavengers (N-acetylcysteine, glutathione ethyl ester, and trolox) inhibited thioridazine plus TRAIL-induced apoptosis, as well as Akt inhibition and the downregulation of c-FLIP(L) and Mcl-1. Collectively, our study demonstrates that thioridazine enhances TRAIL-mediated apoptosis via the ROS-mediated inhibition of Akt signaling and the downregulation of c-FLIP(L) and Mcl-1 at the post-translational level.     

Enantioseparation of hydrochloride salts using carbon dioxide-based mobile phases with on-line polarimetric detection

Most HPLC enantioseparations of amine analytes are performed using normal-phase systems containing mobile phases of heptane with ethanol (or 2-propanol) and an amine additive. Since salt-forms of amine analytes are usually insoluble in normal-phase eluents, free-base forms are synthesized for preparative chromatography. It would be highly desirable to directly chromatograph salt forms of amine analytes using mobile phases of carbon dioxide (CO(2)) and methanol (MeOH). Such separations would be readily suitable for preparative chromatography, since most amine salts are highly soluble in MeOH. In this article, advantages are shown for the use of supercritical fluid chromatography (SFC) instrumentation with tandem UV and polarimetric detection for confirming enantioseparation as well as for determining optimum preparative column injections. Examples are shown for racemic mixtures of propranolol HCl (I), thioridazine HCl (II), tramadol HCl (III), and flurbiprofen (IV), all of which resolved on Chiralpak AD-H chiral stationary phase using mobile-phase systems of CO(2) and MeOH without the use of basic or acidic additives.     

Effect of thioridazine on gap junction intercellular communication in connexin 43-expressing cells

Propagation of electrical activity between myocytes in the heart requires gap junction channels, which contribute to coordinated conduction of the heartbeat. Some antipsychotic drugs, such as thioridazine and its active metabolite, mesoridazine, have known cardiac conduction side-effects, which have resulted in fatal or nearly fatal clinical consequences in patients. The physiological mechanisms responsible for these cardiac side-effects are unknown. We tested the effect of thioridazine and mesoridazine on gap junction-mediated intercellular communication between cells that express the major cardiac gap junction subtype connexin 43. Micromolar concentrations of thioridazine and mesoridazine inhibited gap junction-mediated intercellular communication between WB-F344 epithelial cells in a dose-dependent manner, as measured by fluorescent dye transfer. Kinetic analyses demonstrated that inhibition by 10 μmol/L thioridazine occurred within 5 min, achieved its maximal effect within 1 h, and was maintained for at least 24 h. Inhibition was reversible within 1 h upon removal of the drug. Western blot analysis of connexin 43 in a membrane-enriched fraction of WB-F344 cells treated with thioridazine revealed decreased amounts of unphosphorylated connexin 43, and appearance of a phosphorylated connexin 43 band that co-migrated with a “hyperphosphorylated” connexin 43 band present in TPA-inhibited cells. When tested for its effects on cardiomyocytes isolated from neonatal rats, thioridazine decreased fluorescent dye transfer between colonies of beating myocytes. Microinjection of individual cells with fluorescent dye also showed inhibition of dye transfer in thioridazine-treated cells compared to vehicle-treated cells. In addition, thioridazine, like TPA, inhibited rhythmic beating of myocytes within 15 min of application. In light of the fact that the thioridazine and mesoridazine concentrations used in these experiments are in the range of those used clinically in patients, our results suggest that inhibition of gap junction intercellular communication may be one factor contributing to the cardiac side-effects observed in some patients taking these medications.     

Diastereotopic analysis of mesoridazine besylate (Serentil)

NMR studies were conducted with the aim of determining the diastereoisomeric ratio of a commercially supplied sample of mesoridazine (MES) and to compare the results with a freshly synthesised sample of MES. The results indicated that the commercially supplied MES consisted almost entirely of one diastereoisomeric pair, which was in agreement with previous findings reported by Eap et al. The synthesised sample of MES was analysed by NMR in two stages: 1) as the initial product isolated as the free base from the direct synthesis, and 2) as the free base isolated from the crystallised besylate salt of the synthetic product. The NMR results show that the initial synthetic product consisted of two equal pairs of diastereoisomers. The diastereoisomeric pairs were further separated by the addition of the chiral shift reagent (R)-(-)-N-(3,5 dinitrobenzoyl)-alpha-benzylamine to reveal equal quantities of all four enantiomers, clearly observed at the methyl sulfoxide proton peak of the NMR scan. The sample obtained from the crystallisation of MES besylate, however, indicated a significant difference, with a diastereoisomeric ratio of 75:25. The results suggest that MES besylate undergoes preferential crystallisation of one pair of diastereoisomers, with the other pair remaining in solution.     

硫利达嗪联合溶瘤腺病毒ZD55-TRAIL对HeLa细胞抑制作用及其机制探讨

靶向基因-病毒治疗方法是近年来产生的一种较为有效的癌症生物治疗方法。但其癌症治疗效果仍需进一步提高。在该研究工作中,通过联合使用临床神经治疗药物硫利达嗪（thior_idazine）与溶瘤腺病毒ZD55-TRAIL来增强对HeLa细胞的杀伤作用。通过MTT实验、倒置显微镜观察、结晶紫染色实验观察了联合使用thioridazine和ZD55-TRAIL对子宫颈癌细胞株HeLa细胞的毒性作用;使用Hoechst33342染色、流式细胞实验和Western blot实验检测了联合使用thioridazine和ZD55-TRAIL在引起HeLa细胞发生凋亡上的作用。结果表明,小分子药物thioridazine与病毒ZD55-TRAIL联合使用可以增强对HeLa细胞的杀伤作用,通过下调抗凋亡蛋白XIAP的水平,更显著地促进HeLa细胞发生凋亡。该研究首次报道了联合使用精神疾病药物thioridazine和ZD55-TRAIL对子宫颈癌细胞HeLa的抑制作用,可能是子宫颈癌治疗的一种有效方法。