High-Performance Thin-Layer Chromatography Method for Simultaneous Determination of Antipsychotic and Medicinally Important Five ß-Carboline Alkaloids.

This is the first report on the development and validation of high-performance thin-layer chromatography (HPTLC) method for simultaneous analysis of five antipsychotic and medicinally important ß-carboline alkaloids (ßCAs), namely, harmalol, harmaline, harmine, harmane and norharmane. These ßCAs occurs in both plant and animal system including human being. In the present investigation, their best separation was achieved using an optimized mobile phase, chloroform: methanol: glacial acetic acid (7.8:2.2:0.2, v/v/v) on aluminum TLC plates precoated with silica gel 60 F254. The quantification was performed by densitometric scanning in fluorescence mode at 366 nm. The calibration curves were drawn using linear regression, plotted over the range 25-250 ng band-1 of standard ßCAs with correlation coefficient (R2) between 0.97 and 0.992. Accuracy in terms of recovery (83.95-112.40%), repeatability of application (0.61-2.42%), repeatability of measurement (1.94-3.05%) and intermediate precision (0.62-11.16%) of developed method were simultaneously determined. The limit of detection and limit of quantification were between 4.95-6.59 and 16.50-21.93 ng band-1, respectively. The method was validated according to ICH guidelines and was simple, cost-effective, precise, sensitive and specific for the determination of ßCAs in herbs, Fagonia schweinfurthii, Peganum harmala and Tribulus terrestris. The developed HPTLC method would have importance in forensic and industrial chromatographic analysis and fingerprinting of various herbs and drug formulations containing ßCAs.

Mining the Potential of Label-Free Biosensors for In Vitro Antipsychotic Drug Screening.

The pharmaceutical industry is facing enormous challenges due to high drug attribution rates. For the past decades, novel methods have been developed for safety and efficacy testing, as well as for improving early development stages. In vitro screening methods for drug-receptor binding are considered to be good alternatives for decreasing costs in the identification of drug candidates. However, these methods require lengthy and troublesome labeling steps. Biosensors hold great promise due to the fact that label-free detection schemes can be designed in an easy and low-cost manner. In this paper, for the first time in the literature, we aimed to compare the potential of label-free optical and impedimetric electrochemical biosensors for the screening of antipsychotic drugs (APDs) based on their binding properties to dopamine receptors. Particularly, we have chosen a currently-used atypical antipsychotic drug (Buspirone) for investigating its dopamine D3 receptor (D3R) binding properties using an impedimetric biosensor and a nanoplasmonic biosensor. Both biosensors have been specifically functionalized and characterized for achieving a highly-sensitive and reliable analysis of drug-D3R binding. Our biosensor strategies allow for comparing different affinities against the D3R, which facilitates the identification of strong or weak dopamine antagonists via in vitro assays. This work demonstrates the unique potential of label-free biosensors for the implementation of cost-efficient and simpler analytical tools for the screening of antipsychotic drugs.

Efficacy of drug screening in forensic autopsy: retrospective investigation of routine toxicological findings.

Toxicological analysis is indispensable in forensic autopsy laboratories, but often depends on the limitations of individual institutions. The present study reviewed routine drug screening data of forensic autopsy cases (n=2996) during an 18.5-year period (January 1996-June 2014) at our institute to examine the efficacy of the procedures and findings in autopsy diagnosis and interpretation. Drug screening was performed using on-site immunoassay screening devices and gas chromatography/mass spectrometry (GC/MS) in all cases, followed by re-examination using GC/MS and liquid chromatography/tandem mass spectrometry (LC/MS/MS) at a cooperating institute in specific cases in the last 4 years. GC/MS detected drugs in 486 cases (16.2%), including amphetamines (n=160), major tranquilizers (n=72), minor tranquilizers (n=294), antidepressants (n=21), cold remedies (n=77), and other drugs (n=19). Among these cases, fatal intoxication (n=123) involved amphetamines (n=73), major tranquilizers (n=37), minor tranquilizers (n=86), antidepressants (n=3), and cold remedies (n=9); most cases involved self-administration, alleged suicide and accidental overdose, while homicide was not included. These drugs were also identified in other manners of death, including homicide (n=40/372), suicide (n=34/226), accidental falls (n=27/129), and natural death (n=72/514). In these cases, on-site immunoassay screening of drugs of abuse showed negative findings in 2440 cases (81.4% in all cases), while GC/MS detected other drugs in 218 cases (7.3% in all cases), including several antipsychotic drugs, acetaminophen and salicylic acid. Further analysis using LC/MS/MS detected low concentrations of benzodiazepines in 32 cases, and also anti-diabetic and hypertensive drugs in a case of fatal abuse. These observations indicate the efficacy of systematic routine toxicological analysis to investigate not only the cause of death but also the background of fatalities in forensic autopsy. The provision of extensive drug screening is needed for forensic and social risk management, considering the marked diversity of medical and illicit drugs.

Enantioselective analysis of amisulpride in pharmaceutical formulations by means of capillary electrophoresis.

A capillary electrophoretic method has been developed for the enantioselective analysis of amisulpride in pharmaceutical formulations, using beta-cyclodextrin sulfate as the chiral selector. Several parameters, such as cyclodextrin type and concentration, buffer concentration and pH and capillary temperature were investigated for method optimisation. Baseline enantioseparation of the racemic compound was achieved in less than 10 min using a fused silica capillary (50 microm i.d. and 33.0, 8.5 cm, total and effective length, respectively), filled with a background electrolyte consisting of a 10mM citrate buffer at pH 3.5 supplemented with 0.22% (w/v) beta-cyclodextrin sulfate at 20 degrees C and applying a voltage of +15 kV. Formulation analysis was carried out after analyte extraction by methanol. The method was fully validated, with good results in terms of precision, selectivity, accuracy and amount of drug found with respect to the label claim. Thus, the method seems to be suitable for the enantiomeric analysis of amisulpride in pharmaceutical formulations.

An on-chip cardiomyocyte cell network assay for stable drug screening regarding community effect of cell network size.

We investigate the effect of haloperidol on a four-cell and nine-cell cardiomyocyte network on an agarose microchamber array chip to evaluate a cell-based model for drug screening. Using a network of cardiomyocytes whose beating intervals were stable and relatively uniform (they only fluctuated 10% from the mean beating interval), we easily observed the effect of haloperidol on the cell network beating interval 5 min after administering it. We also observed the beating interval returned to its original state 10 min after the haloperidol was washed out of the chip. Although the four-cell network showed the unstable recovery of its beating rhythm after washout of haloperidol, the nine-cell network recovered completely to the stable original beating rhythm even after a second administration of haloperidol. The results indicate the importance of the community size in cell networks used in the stable cell-based screening model. Moreover, they indicate the advantage of using direct cell-based measurements in which the amount of drug administered and the time course over which it is administered are strictly controlled for evaluating the quantitative chemical effects of drugs on cells.

Compatibility of lithium citrate syrup with 10 neuroleptic solutions.

The visual compatibility of lithium citrate syrup (1.6 meq Li+/ml) in mixtures with each of 10 neuroleptic drug solutions or concentrates was studied. Lithium citrate syrup (5 or 10 ml) was mixed with four volumes (representing minimal to maximal clinical dosages) of each of 10 liquid neuroleptic drug products--chlorpromazine hydrochloride, haloperidol lactate, thioridazine hydrochloride, trifluoperazine hydrochloride, fluphenazine hydrochloride, loxapine hydrochloride, mesoridazine besylate, molindone hydrochloride, perphenazine, and thiothixene hydrochloride. Samples were prepared in duplicate by both orders of mixing at 25 +/- 2 degrees C and 4 +/- 1 degrees C and observed visually immediately and six hours later. Samples observed to be incompatible were centrifuged, and resulting layers were tested for drug with thin-layer chromatography. At six hours after mixing, pH values of the mixtures were measured. Chlorpromazine, haloperidol, thioridazine, and trifluoperazine products were incompatible with lithium citrate syrup; other products were compatible. Centrifugation of incompatible mixtures yielded two liquid phases--a more voluminous clear supernatant and a viscous, translucent, hydrophobic sediment. Thin-layer chromatography verified the presence of the neuroleptic drug in both phases. The incompatibility is independent of pH and lithium or citrate ions. The four incompatible neuroleptic solutions were each mixed with 1.64 M sodium chloride solution, and the same incompatibility was noted as with 5 ml of lithium citrate syrup. This suggested that the precipitation is caused by excessive ionic strength in the mixtures, resulting in salting out of undissociated, solvated ion pairs of the protonated neuroleptic bases and their respective anions. The incompatible mixtures should be avoided because clinically important underdoses could occur.