122 research outputs found
Caratteristiche tossicologiche ed ambientali della CO2
No full textI valori di anidride carbonica atmosferica sono in aumento secondo un trend che nel ventesimo secolo è diventato esponenziale, destando grande preoccupazione nella comunità scientifica. Infatti, secondo gli studiosi, l’aumento della CO2 atmosferica rappresenta un grave problema. L’anidride carbonica è il principale responsabile (anche se non l'unico) dell’effetto serra, in virtù della sua caratteristica di assorbire e trattenere la radiazione termica che la Terra emette dopo aver assorbito l’energia solare; ne deriva un aumento della temperatura del pianeta, le cui conseguenze vanno dal discioglimento dei grandi ghiacci polari con conseguente aumento del livello dei mari, ad uno sconvolgimento dell’intero ecosistema terrestre. Per risolvere questo problema, i leader dei paesi industrializzati nel 1997 con il Protocollo di Kyoto si sono impegnati a ridurre le emissioni dei gas serra (quali anidride carbonica, metano, ossidi nitrosi e composti fluorurati) del 5,2% rispetto ai livelli del 1990. Tuttavia, nel 2002 il livello di riduzione raggiunto dai quindici membri dell'Unione Europea che hanno ratificato l'accordo era solo del 2,9% a fronte di una riduzione del 4,8% prevista. Occorre attuare in tempi rapidi una politica energetica che impieghi sorgenti energetiche rinnovabili e non inquinanti, assieme ad opportune strategie di riduzione delle emissioni di anidride carbonica, quali adeguate procedure di stoccaggio
Iloperidone: a new benzisoxazole atypical antipsychotic drug: is it nove enough to impact the crowded atypical antipsychotic market?
No full textIloperidone (Zomaril®) is a new generation atypical antipsychotic agent, acting as a
5-HT2A/D2 antagonist, currently under development by Vanda Pharmaceuticals for the treatment of schizophrenia, bipolar disorder and other psychiatric conditions.
Chemically Iloperidone is a benzisoxazole, like Risperidone, and shows a multiple receptor binding profile, sharing this feature with the other atypical antipsychotic agents.
Administered orally, the drug is highly bound to plasma proteins and extensively metabolised; reduced Iloperidone is the main active metabolite.
Several clinical trials were carried out, to check efficacy, safety and side effects.
In order to introduce Iloperidone as an agent for the treatment of schizophrenia, a short overview of the disease and of the most important available or under development antipsychotic drugs will be reported as well.
Iloperidone pharmacokinetics and pharmacodynamics are presented herein, together with an evaluation of clinical safety and efficacy results
Therapeutic drug monitoring of recent antidepressants in patients under polypharmacy
No full textThe introduction into clinical practice of the so-called second generation antidepressants has improved the treatment of depression, since these drugs, compared to the first generation antidepressants (such as imipramine and clomipramine), show a more favourable safety profile with respect to cardiovascular effects, whilst maintaining efficacy. Nevertheless, patients treated with these newer antidepressants can present undesired effects, including serotonin syndrome, sedation, body weight changes, sexual dysfunction and suicidal ideation. Therefore, with the aim of reducing the risk for toxic/side effects, therapeutic drug monitoring (TDM) of second generation antidepressants is advisable, particularly in case of patients under polypharmacy. During the last years, a number of methods have been developed in our Laboratory for the accurate determination of antidepressant drugs and their metabolites in plasma samples obtained from patients, including drugs belonging to different classes of second-generation antidepressants (SSRI, NaSSA, SNRI). Sertraline, together with its main metabolite N-desmethylsertraline, can be analysed in plasma samples using a method based on capillary electrophoresis with laser-induced fluorescence (LIF) detection. The method employs a 488 nm wavelength laser and a sample pre-treatment procedure consisting in solid-phase extraction followed by derivatisation with fluorescein isothiocyanate. The high selectivity obtained allows the determination of sertraline in plasma samples from patients under polypharmacy.
Capillary electrophoresis with diode-array detection has been employed for the enantioselective determination of mirtazapine and its active metabolite N-desmethylmirtazapine in human plasma. The method is quite fast: after a solid-phase extraction procedure, the electrophoretic run lasts 2.5 min.
HPLC with fluorescence detection has been used for the determination of venlafaxine together with its main metabolite O-desmethylvenlafaxine, while HPLC coupled to UV detection was employed for the analysis of duloxetine in plasma of depressed patients
Separation of ethoxylated bisphenol A dimethacrilates in dental composite after derivatisation to ionisable amines by capillary zone electrophoresis
No full textBisphenol A ethoxylate dimethacrylates (Bis-EMA) are transformed into ionisable amines by derivatisation in order to make the analytes
applicable to capillary electrophoresis. For this goal, piperidine was added onto the C=C double bond of the alpha,beta-unsaturated ester group forming a tertiary amine with pKa values between 9 and 10. Formation of the derivatives was confirmed by electrospray ionisation MS. Commercial Bis-EMA is a mixture of homologues with different number of ethoxy groups; it is characterised by the average number of the ethoxy groups in the chains. These homologues were resolved by capillary zone electrophoresis at pH 4. It is shown for the product with an average of four ethoxy groups per Bis-EMA molecule that about seven homologues can be baseline separated when differing by only one ethoxy group. For Bis-EMA with 30 ethoxy groups in average, about 23 homologues could be differentiated. The high resolution power of
capillary zone electrophoresis enables characterisation of commercial dental composite material concerning the Bis-EMA constituents
Chitosan salts coated with stearic acid as colon-specific delivery systems for vancomycin.
No full textSite-specific controlled release systems have been extensively investigated during the last decade. The aim of this study was to describe a pH-dependent drug release system based on chitosan salts for vancomycin hydrochloride delivery. Chitosan salts with succinic acid, adipic acid, and suberic acid were prepared by spray-drying and were coated with stearic acid by the same technique. This study characterized the carriers in terms of morphology, size, swelling, mucoadhesive properties, and drug loading and focused on the in vitro, influence of chitosan salts on the release behavior of vancomycin hydrochloride from the uncoated and coated systems at pH levels of 2.0, 5.5, and 7.6
Comparison of analytical methods for the quality control of a new formulation containing soy extract and melatonin
No full textThree analytical methods have been developed and compared for the quality control of a new formulation (Soymen GN® capsules) containing soy extract and melatonin for the treatment of menopausal symptoms. The first method is based on micellar electrokinetic chromatography (MEKC) with diode-array detection, using a mixture of basic carbonate buffer (95%) and methanol (5%), containing 55 mM SDS, as the background electrolyte. The second method is a high-performance liquid chromatographic (HPLC) method with ultraviolet detection at 260 nm. The third method is an HPLC method coupled to amperometric detection which is carried out at an oxidation potential of + 0.8 V. In both HPLC systems, the chromatographic separation is obtained on a reversed-phase C18 column using a mixture of acetonitrile and an acidic phosphate buffer (25/75, v/v) as the mobile phase. A feasible pre-treatment procedure with a methanol/water mixture has been implemented to achieve the quantitative extraction of the main soy isoflavones and of melatonin from the capsules. The results obtained with the three methods are in good agreement with each other and satisfactory in terms of linearity (r2 > 0.9996), precision (RSD 97%). Thus, each of the three analytical methods seems to be suitable for the simultaneous analysis of the main soy isoflavones and melatonin in the new commercial formulation
Determination of sertraline and N-desmethylsertraline in human plasma by CE with LIF detection
No full textA method has been developed for the analysis of the antidepressant drug sertraline together with its main metabolite N-desmethylsertraline (DMS) in human plasma. It is based on CE with LIF detection (lambda = 488 nm). A SPE procedure is employed for biological sample pretreatment, followed by a derivatization step with FITC; reboxetine was the internal standard. The effect of CD, acetone and N-methyl-D-glucamine (GLC) as constituents of the BGE for analyte separation was investigated. The final BGE consisted of 20 mM carbonate buffer, pH 9.0, with 2.5 rnM heptakis(2,6-di-O-methyl)-beta-CD, 50 mM GLC and 20% v/v acetone. With 30 W applied voltage, the electrophoretic run is completed in 7.5 min. Linearity was observed in the plasma concentration range from 3.0 to 500 ng/mL for sertraline and 4.0 to 500 ng/mL for DMS. Extraction yield was >97.1%, precision - expressed as RSD% - was 95.6%. Due to its sensitivity and selectivity, the method was suited for the analysis of plasma samples from patients undergoing therapy with sertraline
Simultaneous determination of aromatic and terpenic constituents of cloves by means of HPLC with diode array detection
No full textAn HPLC method has been developed for the simultaneous determination of aromatic and terpenic constituents of cloves on a C8 RP column, with the mobile phase consisting of a pH 3.5 phosphate buffer-triethylamine (30%) and acetonitrile (70%); a flow rate of 1.2 mL/min and a diode-array detector were used. Complete separation of all analytes (eugenol (EUG), eugenol acetate (AEUG), beta-caryophyllene, alpha-humulene and caryophyllene oxide) was achieved within 7 min. Good linearity was found in the range 0.125–40.0 μg/mL for EUG and AEUG and in the range 0.250–20.0 μg/mL for the terpenic compounds. After validation, the method was successfully applied to the analysis of clove oil and clove extract samples. The results obtained indicate good accuracy (recovery percentage mean value corresponding to 99.9%) and satisfactory precision
Therapeutic drug monitoring: analysis of the novel antipsychotic aripiprazole in human plasma
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