Efficacy of Palbociclib and Endocrine Treatment in Heavily Pretreated Hormone Receptor-positive/HER2-negative Advanced Breast Cancer: Retrospective Multicenter Trial

Background: The synthesis of CDK4/6 inhibitors with endocrine treatment in two series of treatment has been widely accepted as the standard for patients with estrogen receptor-positive metastatic breast cancer. In spite of this, the activity of CDK4/6 inhibitors in patients with metastatic breast cancer who have progressed despite receiving multiple lines of treatment is not well understood. Aims: To report the activity and safety of a CDK4/6 inhibitor (palbociclib) in patients in whom at least three lines of treatment for ER+ metastatic breast cancer had failed. Study Design: Multicenter retrospective observational cohort study. Methods: In this retrospective observational cohort study, we included 43 patients who received palbociclib after at least three lines of systemic treatment for ER+/HER2− metastatic breast cancer. Results: The median progression-free survival in our population was 7 months (25th-75th percentile, 4-10), and the median overall survival was 11 months (25th-75th percentile, 6-19). Although there were some adverse events, palbociclib was generally well tolerated, so dose reduction was needed for only six patients (14%). Conclusion: The efficacy of palbociclib among heavily treated hormone receptor-positive/HER2− patients with advanced breast cancer was acceptable in terms of clinical benefit, and it was generally well tolerated among this population.

Simultaneous determination of the counter ion and possible impurity from the synthetic route in the pharmaceutical substance prasugrel hydrochloride.

A fast and selective capillary electrophoresis method was developed and validated for the simultaneous determination of the hydrochloride and acetic acid content in prasugrel hydrochloride. Because of the poor chromophore, the indirect detection was chosen. Among different compositions studied as the background electrolyte, the pyromellitic acid with diethylamine (DEA) and myristyltrimethylammonium bromide (TTAB) was chosen. During the validation the specificity, linearity, accuracy, precision, range, and stability of the sample solution were confirmed. The results indicate that the method is suitable for the determination of the counter ion and impurity from the synthetic route of the pharmaceutical drug substance in the same assay.

Evaluation of the residual solvent content of counterfeit tablets and capsules.

A group of counterfeit samples of Viagra and Cialis were screened for their residual solvent content and compared to the content of the genuine products. It was observed that all counterfeit samples had higher residual solvent contents compared to the genuine products. A more diverse range of residual solvents was found as well as higher concentrations. In general these concentrations did not exceed the international imposed maximum limits. Only in a few samples the limits were exceeded. A Projection Pursuit analysis revealed clusters of samples with similar residual solvent content, possibly enabling some future perspectives in forensic research.

Detection and structure elucidation of hydroxythiovardenafil as an adulterant in a herbal dietary supplement.

A new derivative of vardenafil was detected in an alleged herbal dietary supplement and identified as 2-(2-ethoxy-5-(4-(2-hydroxyethyl)piperazin-1-ylsulfonyl)phenyl)-5-methyl-7-propyl-imidazo[1,5-f][1,2,4]triazin-4(3H)-thione. Structure elucidation was carried out by LC-UV-MS/MS and NMR. Results obtained with high resolution MS and IR spectroscopy confirmed the proposed chemical structure. The compound was distinguished from hydroxyvardenafil, a second active substance identified in the same product, by the conversion of the oxo group to a thio group on the imidazo-triazin moiety. Hydroxythiovardenafil was therefore suggested as a proprietary name for the new molecule. This is the first paper to describe a thio-analog of vardenafil in a commercially available product.

VICTORY project: a study of counterfeit PDE5 inhibitor (sildenafil) in Indonesia.

AIM: to quantify the extent of counterfeit sildenafil in Indonesia. METHODS: the study was conducted in 4 big areas: Jakarta, Bandung, East Java (Surabaya and Malang), and Medan. Sildenafil 100 mg tablets were purchased from pharmacies, drugstores, street peddlers, and 3 Indonesian websites. The outlets were chosen by random sampling in each stratum (type of outlet). Sildenafil tablets purchased were sent to Pfizer Quality Operations Division, Dalian, China, for authenticity evaluations (by infra red spectral analysis). All counterfeit tablets were then sent to Pfizer Counterfeit Medicines Laboratory, Sandwich, UK, a portion of which were analyzed quantitatively for sildenafil concentration per tablet (by HPLC). RESULTS: a total of 518 sildenafil 100 mg tablets were collected and sent to Dalian. Of these tablets, 284 tablets (55%) were genuine sildenafil and 234 tablets (45%) were counterfeit sildenafil. Counterfeit sildenafil were mostly found in street peddlers (100%), in drugstores (56%), and from internet (33%), but pharmacies also had (13%) counterfeit sildenafil. The sildenafil content of 106 counterfeit tablets analyzed varied from 24 to 157 mg per 100 mg tablet. No analysis was done to determine other active ingredient. CONCLUSION: 45% sildenafil 100 mg tablets in Indonesia were found counterfeit and widely distributed in street peddlers, drugstores, and pharmacies. This report is aimed to alert the potential consumers, health professionals and regulators of this problem.

Determination of imatinib mesylate and related compounds by field amplified sample stacking with large volume sample injection capillary electrophoresis.

Imatimib mesylate is a drug for the treatment of gastrointestinal stroma tumor and chronic myelogenous leukemia. In this study, capillary electrophoretic analysis of imatinib mesylate and related compounds was developed. The optimized separation condition was NaH(2)PO(4) (10 mM) aqueous solution containing 5 mM of 2-hydroxypropyl-ß-cyclodextrin at a pH of 2.0. The separation could be obtained in less than 20 min when the separation voltage was 20 kV. To enhance the sensitivity, field amplified sample stacking combining with large volume sample injection was adopted. The optimal injection conditions were obtained by using methanol containing 0.5 mM HCl as the sample dilution solution and performing injection at a voltage of 15 kV for 60 s. The linearity ranges of ima amine, N-desmethyl imatinib and imatinib mesylate were 0.005-0.500 µg/ml, and 4-chloromethyl-N-(4-methyl-3-((4-(pyridin-3-yl) pyrimidin-2-yl) amino) phenyl) benzamide was 0.010-0.500 µg/ml, with good linear correlation coefficients (r(2)>0.9900). The intra-day and inter-day relative standard deviations of peak areas were satisfactory. Under the optimized condition, five batches of the synthesized samples were detected and ima amine was found in all the batches. Due to its simplicity, effectiveness and low price, the developed method can be used for quality control analysis of imatinib mesylate.

Development and validation of a stability-indicating gas chromatographic method for quality control of residual solvents in blonanserin: a novel atypical antipsychotic agent.

Blonanserin is a novel atypical antipsychotic agent for the treatment of schizophrenia. Ethyl alcohol, isopropyl alcohol and toluene are utilized in the synthesis route of this bulk drug. A new validated gas chromatographic (GC) method for the simultaneous determination of residual solvents in blonanserin is described in this paper. Blonanserin was dissolved in N, N-dimethylformamide to make a sample solution that was directly injected into a DB-624 column. A postrun oven temperature at 240°C for approximately 2 h after the analysis cycle was performed to wash out blonanserin residue in the GC column. Quantitation was performed by external standard analyses and the validation was carried out according to International Conference on Harmonization validation guidelines Q2A and Q2B. The method was shown to be specific (no interference in the blank solution), linear (correlation coefficients ≥0.99998, n = 10), accurate (average recoveries between 94.1 and 101.7%), precise (intra-day and inter-day precision ≤2.6%), sensitive (limit of detection ≤0.2 ng, and limit of quantitation ≤0.7 ng), robust (small variations of carrier gas flow, initial oven temperature, temperature ramping rate, injector and detector temperatures did not significantly affect the system suitability test parameters and peak areas) and stable (reference standard and sample solutions were stable over 48 h). This extensively validated method is ready to be used for the quality control of blonanserin.

Stability-indicating UPLC method for determination of Imatinib Mesylate and their degradation products in active pharmaceutical ingredient and pharmaceutical dosage forms.

A simple, precise, accurate stability-indicating gradient reverse phase ultra-performance liquid chromatographic (RP-UPLC) method was developed for quantitative determination of purity of Imatinib Mesylate (IMM) drug substance and drug products in the presence of its process related impurities, and degradation products. The proposed RP-UPLC method utilizes Acquity UPLC BEH 50-mm, 2.1mm and 1.7 µm C-18 column at 30 °C, with a gradient program of 9.0 min at a flow rate of 0.3 mL/min. The compounds of interest were monitored at 237 nm. Resolution for Imatinib and eight related components was found to be greater than 1.5 for any pair of components. The correlation coefficients (r(2)>0.9990) obtained indicate clear correlations between the concentrations and their peak areas for the investigated compounds. RSD obtained for the repeatability and intermediate precision experiments, was less than 5.0%. Accuracy of the method was further ascertained by performing recovery studies through spiking experiments. The drug substance was subjected to hydrolytic, oxidative, photolytic and thermal stress conditions as per ICH. The developed method was validated according to the current ICH guidelines for specificity, limit of detection, limit of quantitation, linearity, accuracy, precision, ruggedness and robustness. The method is also suitable for the assay determination of IMM in pharmaceutical dosage forms.

Rapid and sensitive determination of udenafil in plasma by LC-MS/MS for intranasal pharmacokinetic study in rats.

A rapid and sensitive analytical method for udenafil in rat plasma was developed and validated using liquid chromatography-tandem mass spectrometry (LC-MS/MS). This chromatographic procedure was then applied to the in vivo pharmacokinetic studies in rats for determining the advantages of intranasal administration of the drug over oral administration. Using liquid-liquid extraction (LLE), udenafil and the internal standard (IS) sildenafil were extracted with dichloromethane from 100 µl of plasma samples. Chromatographic separation was performed using Pursuit XRS C18 column (50 mm × 2.1 mm, i.d., 3 µm, Varian Inc., CA, U.S.A.) with an isocratic mobile phase consisting of acetonitrile and 10 mM ammonium acetate (90 : 10, v/v) at a flow rate of 0.2 ml/min over a total run time of 2.5 min. Detection and quantification was performed by mass spectrometry using the multiple reaction-monitoring mode at m/z 517.4→283.1 for udenafil and m/z 475.3→100.0 for IS. Results showed that the developed method was sensitive and specific for udenafil. Linearity was obtained in the range of 0.5-1000 ng/ml. The coefficient of variation of both intra- and inter-day validation were below 11.6% and the intra- and inter-day accuracy ranged from 91.5 to 109.9%. Udenafil concentration was successfully measured from plasma after intranasal as well as after intravenous or oral administration at clinical dose (1.67 mg/kg) in rats. Moreover, the T(max) values obtained from pharmacokinetic studies suggested that administration of udenafil intranasally could be more effective than by the oral route.

The trazodone metabolite meta-chlorophenylpiperazine can cause false-positive urine amphetamine immunoassay results.

Amphetamines and methamphetamines are part of an important class of drugs included in most urine drugs of abuse screening panels, and a common assay to detect these drugs is the Amphetamines II immunoassay (Roche Diagnostics). To demonstrate that meta-chlorophenylpiperazine (m-CPP), a trazodone metabolite, cross-reacts in the Amphetamines II assay, we tested reference standards of m-CPP at various concentrations (200 to 20,000 g/L). We also tested real patient urine samples containing m-CPP (detected and quantified by HPLC) with no detectable amphetamine, methamphetamine, or MDMA (demonstrated by GC MS). In both the m-CPP standards and the patient urine samples, we found a strong association between m-CPP concentration and Amphetamines II immunoreactivity (r = 0.990 for the urine samples). Further, we found that patients taking trazodone can produce urine with sufficient m-CPP to result in false-positive Amphetamines II results. At our institution, false-positive amphetamine results occur not infrequently in patients taking trazodone with at least 8 trazodone-associated false-positive results during a single 26-day period. Laboratories should remain cognizant of this interference when interpreting results of this assay.

Determination of exposure multiples of human metabolites for MIST assessment in preclinical safety species without using reference standards or radiolabeled compounds.

A simple, reliable, and accurate method was developed for quantitative assessment of metabolite coverage in preclinical safety species by mixing equal volumes of human plasma with blank plasma of animal species and vice versa followed by an analysis using high-resolution full-scan accurate mass spectrometry. This approach provided comparable results (within (±15%) to those obtained from regulated bioanalysis and did not require synthetic standards or radiolabeled compounds. In addition, both qualitative and quantitative data were obtained from a single LC-MS analysis on all metabolites and, therefore, the coverage of any metabolite of interest can be obtained.

Safety of the electroconvulsive therapy-ziprasidone combination.

In clinical practice, a nonnegligible proportion of patients with mood or psychotic disorders undergo electroconvulsive therapy (ECT) concomitantly with pharmacotherapy. Ziprasidone, a combined serotonin and dopamine receptor antagonist, is a second-generation antipsychotic agent with a lower incidence of extrapyramidal motor symptoms and prolactin elevation and a safer profile of adverse effects on plasma lipids, glucose levels, and body weight than other antipsychotics. To the best of our knowledge, there are as yet no available reports on the safety of the ECT-ziprasidone combination. We report here on a series of 8 female inpatients who underwent ECT while receiving ziprasidone (20-80 mg/d) as part of their regimen. Seven patients were treated for major depressive episode in the context of unipolar major depressive disorder (n = 5) or of bipolar disorder I (n = 2), whereas 1 patient was treated for exacerbation of schizophrenic symptoms. In all cases, the combination was well tolerated with only minimal adverse effects and unremarkable changes in corrected QT interval.

[Counterfeit phosphodiesterase type 5 inhibitors--growing safety risks for public health]. / Sfalszowane inhibitory fosfodiesterazy typu 5--narastajace zagrozenie dla zdrowia publicznego.

Counterfeit drugs, medical devises and dietary supplements are inherently dangerous and a growing problem. In Europe the growth of the counterfeit medication market is attributable in part to registration of phosphodiesterase type 5 inhibitors (PDE-5) used for the erectile dysfunction. "Viagra, Levitra and Cialis belong to this group. It has been estimated that up to 2.5 million men in Europe are exposed to an illicit sildenafil, suggesting that there may be as many illegal as legal users of sildenafil. In Europe a strong trend is observed towards increasingly professional counterfeits and imitations of Viagra, Cialis and Levitra, with regard to the appearance of tablets, capsules and packaging. The professional presentation will deceive potential consumers into assuming these products are legal, efficacious and safe. Globally, increased obstacles for counterfeiters are necessary to combat pharmaceutical counterfeiting, including fines and penalties. The worldwide nature of the counterfeit problem requires proper coordination between countries to ensure an adequate enforcement. We described the usefulness of the time-of-flight mass spectrometry with the electrospray ionization (LC-ESI-MS-TOF) and the X-ray powder diffraction method (XRPD) for PDE-5 counterfeit screening from the Polish illegal market.

Safety and quality assessment of 175 illegal sexual enhancement products seized in red-light districts in Singapore.

BACKGROUND: In recent years, there has been increasing interest in the use of herbs and supplements as an alternative to drugs used for the treatment of erectile dysfunction, in order to enhance sexual performance. Over the years, adverse events associated with the consumption of natural health products for sexual enhancement and the treatment of erectile dysfunction have been reported. OBJECTIVE: The objective of this work was to assess the safety and quality of 175 sexual enhancement health products seized from makeshift stalls in red-light districts of Singapore. METHOD: Seven raids were conducted by the Health Sciences Authority, Singapore, in two red-light districts in February and March 2008. 175 sexual enhancement health products seized from makeshift stalls were extracted with methanol and screened for Western drug adulterants using high performance liquid chromatography and gas chromatography-mass spectrometry. The labels and claims of the products were also evaluated. RESULTS: Of the 175 products evaluated, 134 (77%) were found to be adulterated with Western drugs or their analogues. Most of these 134 samples (123 [92%]) were found to be adulterated with sildenafil. The extent of adulteration of these illegal health products with Western drugs, including synthetic phosphodiesterase type 5 enzyme (PDE-5) inhibitors, and the risks of consuming such illegal sexual enhancement products are discussed in this study. Because of the scope of the raids, sildenafil was the most common adulterant found. In addition, some products were found to contain high contents of sildenafil (>100 mg) and high contents of the antidiabetic drug, glibenclamide (glyburide). The resultant severe hypoglycaemia has led to ten fatalities. CONCLUSION: The presence of Western drug adulterants and their analogues in illegal sexual enhancement products seized from red-light districts in Singapore, and their often misleading labels and claims, put the health of consumers at risk. To safeguard public health, greater public awareness of the danger of consuming such illegal products and the lack of quality control of these illegal sexual enhancement health products is important.

Determination of analogs of sildenafil and vardenafil in foods by column liquid chromatography with a photodiode array detector, mass spectrometry, and nuclear magnetic resonance spectrometry.

Two analogs of sildenafil and vardenafil in food were detected by column liquid chromatography (LC) with a photodiode array detector. They were isolated by preparative LC; their structures were established by mass spectrometry and nuclear magnetic resonance spectrometry. One analog was found to be methisosildenafil (compound A), 5-(5-(3,5-dimethylpiperazin-1-ylsulfonyl)-2-ethoxy-phenyl)-1-methyl-3-propyl-1H-pyrazolo[4,3-d]-pyrimidin-7(6H)-one. It is a sildenafil analog with a dimethylpiperazine ring substituted for the methylpiperazine group. The second analog, hydroxyvardenafil (compound B) is reported for the first time in this study. Hydroxyvardenafil's International Union of Pure and Applied Chemistry name is 2-(2-ethoxy-5-(4-(2-hydroxyethyl)-piperazin-1-ylsulfonyl)phenyl)-5-methyl-7-propyl-imidazo[1,5-f][1,2,4]triazin-4(3H)-one. The novel vardenafil analog has a hydroxyl group added to the ethylpiperazine group.

First demonstration of the effectiveness of inhibitors of cellular protein kinases in antiviral therapy.

Viral replication and pathogenesis involves many cellular protein kinases, and many specific inhibitors of such kinase have been developed for the treatment of noninfectious diseases. As expected, such drugs have been repeatedly demonstrated to inhibit viral replication in cultured cells. Cellular protein kinases have thus been considered for several years as potentially valid targets for antiviral therapy. However, until recently there was no proof of such activity in vivo. The three papers discussed herein demonstrate that inhibitors of cellular protein kinases are indeed effective for the treatment of virus-induced disease in animal models and human clinical trials.

A further study on the combined use of internal standard and isotope-labeled derivatization reagent for expansion of linear dynamic ranges in liquid chromatography-electrospray mass spectrometry.

The combined use of a so-called internal standard and the isotope-labeled derivatization reagent for the quantification of analytes for liquid chromatography-mass spectrometry (LC/MS) was further studied. The sample solution (containing the analytes and an internal standard) was derivatized with the light form of the derivatization reagent, 7-(N,N-dimethylaminosulfonyl)-4-(aminoethyl)piperazino-2,1,3-benzoxadiazole (DBD-PZ-NH(2)) or 7-(N,N-dimethylaminosulfonyl)-4-piperazino-2,1,3-benzoxadiazole (DBD-PZ). A standard solution of the analytes (containing an internal standard) was derivatized with the isotope (d(6))-labeled derivatization reagent, DBD-PZ-NH(2) (D) or DBD-PZ (D), and served as the isotope-labeled internal standards. The peak heights of the targeted analytes derivatives in the sample solution were corrected using those of the internal standard and the heavy form derivatives of the standards, and the calibration curves were constructed. The curve bending of the calibration curves caused by the ion suppression at the ion source was suppressed and the linear dynamic ranges of the calibration curves were expanded. The derivatives of DBD-PZ-NH(2) were about 10 times more sensitively detected than those of DBD-PZ derivatives and, therefore, DBD-PZ-NH(2) might be suitable for sensitive detection.

Viagra's rise above women's health issues: an analysis of the social and political influences on drug approvals in the United States and Japan.

In the United States, Viagra was approved in less than 6 months of its application to the Food and Drug Administration, while the medical abortion pill was approved 4 years after its application, and 17 years after research was first permitted. Congruently, the Ministry of Health in Japan legalized Viagra in 6 months, while oral contraceptives were approved 35 years after the ministry received initial applications. The pharmaceutical review agencies in each country are founded on safety and efficacy standards, in which objective decisions arise from science and clinical investigations. Analyses of these recent drug approvals demonstrate that conclusions may not have been based simply on science and health concerns. Instead, agency actions and application of pharmaceutical law appear to have been influenced by social and political pressures surrounding the products under scrutiny. Pharmaceutical regulations were effectively ignored or manipulated in the United States during the review process for medical abortion, and were applied inconsistently in Japan--ultimately yielding results that happened to conform to contemporary sociopolitical beliefs. Such disregard of legislation holds serious ramifications for public health, national consumer trust and the pharmaceutical industry. It is imperative that external pressures remain outside the scope of drug approval processes.

Screening suspected counterfeit Viagra and imitations of Viagra with near-infrared spectroscopy.

We describe a near-infrared spectroscopy (NIRS) method for fast-screening Viagra tablets, counterfeit Viagra tablets, and imitations of Viagra. The method can (1) check the homogeneity of a batch; (2) distinguish counterfeits and imitations from authentic Viagra; (3) screen for the presence of sildenafil citrate, the pharmacologically active substance in Viagra, irrespectively of the excipients present; (4) and detect whether similar samples have been previously analysed. We applied the method to 103 samples with a diversity of appearance, chemical composition, and origin. Other analytical methods confirmed the positive screening results for sildenafil citrate and the presence of other pharmacological active substances. The NIRS screening indicated the absence of sildenafil citrate in the presence of another pharmacological substance for only 2 samples, where the reference methods showed the presence of sildenafil citrate in addition to that of clomifene citrate. Otherwise, the method gave no false positive or negative results. The NIRS screening method is very fast and reliable for detecting counterfeits and imitations, and it correctly predicts the presence or absence of sildenafil citrate in 98% of the samples.