59 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
Antipsychotic and antiepileptic drugs in bipolar disorder: The importance of therapeutic drug monitoring
No full textBipolar disorder (BD) is a long-term illness with mood swings which are characterized by recurrent episodes of mania/hypomania and depression, with variable interpolations of relatively asymptomatic periods, called euthymic, in which, however, some psychopathological symptoms may persist. Although mood stabilizers, such as lithium, are the first-line treatment for the prevention of new BD episodes, combination therapy has become the standard of care for BD patients. Besides lithium, the use of a mood stabilizer along with an atypical antipsychotic is recommended in many patients. Recently, atypical antipsychotics (quetiapine, olanzapine, risperidone and aripiprazole) and antiepileptic agents (valproate, lamotrigine and oxcarbazepine) are increasingly used as mood stabilizers. To reduce side effects and optimize treatment it is important to perform accurate monitoring of drug blood levels in these patients, who are often treated with multiple drugs. Therapeutic drug monitoring (TDM) is in fact a powerful tool that, starting from clinical-chemical correlation data, allows to tailor-cut treatment to the specific needs of individual patients; hence the need to have reliable analytical methods available for the determination of plasma levels of drugs and their metabolites. Analyses of biological samples are mainly carried out using high-performance liquid chromatography (HPLC) coupled with different detectors, capillary electrophoresis and gas-chromatography. Various procedures are employed to remove biological interferences before analyzing the samples. This review focuses on currently available analytical TDM methods for atypical antipsychotics and antiepileptic agents used in the treatment of patients with bipolar disorder. Advantages and limitations of the various analytical methods will be reviewed and discussed, together with an evaluation of the role of TDM. © 2009 Bentham Science Publishers Ltd
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
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
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
pH-dependent systems for colon delivery of vancomycin
No full textSite-specific controlled release systems offer many advantages over classical methods of drug delivery. These include localized delivery of the drug to a particular part of the body, assurance of drug stability, reduced need for follow up care and optimized drug absorption. In particular the release of orally administred peptidic drugs has attracted growing interest in recent years following the developmet of new delivery systems able to overcome problems due to the acidic environment and enzymatic degradation in the gastrointestinal tract [1].
Chitosan (CH) is a natural derivative of chitin produced by partial N-deacetylation under alkaline conditions. Because of its amino groups, it is a weak base and is insoluble in water and in organic solvents, however it is soluble in dilute aqueous acid solutions (pH < 6.5). Chitosan is a polycation and is able to form salts with a wide variety of acids. Moreover it has interesting biological properties, including biocompatibility and biodegradability and it has been used extensively to prepare hydrogels and microparticles [2].
The aim of this study was to describe a pH-dependent drug release system based on chitosan salts for vancomycin hydrochloride delivery. Chitosan succinate (CH-Suc), chitosan adipate (CH-Ad) and chitosan suberate (CH-Sub) were prepared at different crosslinking degrees by spray-drying and coated with stearic acid by the same technique. Vancomycin hydrochloride was used as a peptidic model drug whose controlled release should minimize its inactivation in the upper part of the gastrointestinal tract. This study characterized the systems in terms of morphology, size, swelling and mucoadhesive properties, drug loading (as assessed by means of an original capillary electrophoresis method) and in particular evaluated, in vitro, the influence of chitosan salts on the release behaviour of vancomycin hydrochloride from the uncoated and coated systems at pH 2.0, 5.5 and 7.6.
Chitosan salts provided different swelling and release behaviour as a function of diacid chain length and crosslinking degree according to a different polymer ability to interact with water. Moreover chitosan salts showed different swelling and release behaviour as a function of enviromental pH according to the net charge balance inside the gel.
The coating process was found to prevent vancomicyn release in acidic conditions allowing the complete release of the peptidic drug in the intestinal fluids.
Chitosan salts coated with stearic acid could serve as potential candidates for antibiotic colon-specific delivery.
References
[1] G. Van den Mooter , Expert Opin. Drug Deliv. 3 (2006) 111.
[2] T. Cerchiara, B. Luppi, F. Bigucci and V. Zecchi, J. Pharm. Pharmacol. 55 (2003) 1623
Antipsychotic and antiepileptic drugs in bipolar disorder: the importance of therapeutic drug monitoring
No full textBipolar disorder (BD) is a long-term illness with mood swings which are characterized by recurrent episodes of mania/hypomania and depression, with variable interpolations of relatively asymptomatic periods, called euthymic, in which, however, some psychopathological symptoms may persist.
Although mood stabilizers, such as lithium, are the first-line treatment for the prevention of new BD episodes, combination therapy has become the standard of care for BD patients. Besides lithium, the use of a mood stabilizer along with an atypical antipsychotic is recommended in many patients. Recently, atypical antipsychotics (quetiapine, olanzapine, risperidone and aripiprazole) and antiepileptic agents (valproate, lamotrigine and oxcarbazepine) are increasingly used as mood stabilizers. To reduce side effects and optimize treatment it is important to perform accurate monitoring of drug blood levels in these patients, who are often treated with multiple drugs. Therapeutic drug monitoring (TDM) is in fact a powerful tool that, starting from clinical-chemical correlation data, allows to tailor-cut treatment to the specific needs of individual patients; hence the need to have reliable analytical methods available for the determination of plasma levels of drugs and their metabolites. Analyses of biological samples are mainly carried out using high-performance liquid chromatography (HPLC) coupled with different detectors, capillary lectrophoresis and gas-chromatography. Various procedures are employed to remove biological interferences before analyzing the samples. This review focuses on currently available analytical TDM methods for atypical antipsychotics and antiepileptic agents used in the treatment of patients with bipolar disorder. Advantages and limitations of the various analytical methods will be reviewed and discussed, together with an evaluation of the role of TDM
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
Enantioselective analysis of amisulpride in pharmaceutical formulations by means of capillary electrophoresis
No full textA capillary electrophoretic method has been developed for the enantioselective analysis of amisulpride in pharmaceutical formulations, using β-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 minutes using a fused silica capillary (50 μm I.D. and 33.0 cm, 8.5 cm, total and effective length, respectively), filled with a background electrolyte consisting of a 10 mM citrate buffer at pH 3.5 supplemented with 0.22% (w/v) β-cyclodextrin sulfate at 20°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
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