177 resultados para Collocation Formulation


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Lipid microspheres (LM) are excellent drug delivery or vaccines adjuvant systems and are relatively stable. The aim of this work is to develop and characterize a system that is able to encapsulate and present antigenic membrane proteins from Leishmania amazonensis. Membrane proteins are important for vaccine`s formulation because these proteins come in contact with the host cell first, triggering the cell mediated immune response. This is a useful tool to avoid or inactivate the parasite invasion. The LM are constituted by soybean oil (SO), dipalmitoylphosphatidilcholine (DPPC), cholesterol and solubilized protein extract (SPE). The particles formed presented an average diameter of 200 run, low polydispersion and good stability for a period of 30 days, according to dynamic light scattering assays. Isopycnic density gradient centrifugation of LM-protein showed that proteins and lipids floated in the sucrose gradient (5-50%w/v) suggesting that the LM-protein preparation was homogeneous and that the proteins are interacting with the system. The results show that 85% of SPE proteins were encapsulated in the LM. Studies of cellular viability of murine peritoneal macrophages show that our system does not present cytotoxic effect for the macrophages and still stimulates their NO production (which makes its application as a vaccine adjuvant possible). LM-protein loaded with antigenic membrane proteins from L. amazonensis seems to be a promising vaccine system for immunization against leishmaniasis. (C) 2009 Elsevier Inc. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

UV-VIS-Spectrophotometric and spectrofluorimetric methods have been developed and validated allowing the quantification of chloroaluminum phthalocyanine (CIAIPc) in nanocarriers. In order to validate the methods, the linearity, limit of detection (LOD), limit of quantification (LOQ), precision, accuracy, and selectivity were examined according to USP 30 and ICH guidelines. Linearities range were found between 0.50-3.00 mu g.mL(-1) (Y=0.3829 X [CIAIPc, mu g.mL(-1)] + 0.0126; r=0.9992) for spectrophotometry, and 0.05-1.00 mu g.mL(-1) (Y=2.24 x 10(6) X [CIAIPc, mu g.L(-1)] + 9.74 x 10(4); r=0.9978) for spectrofluorimetry. In addition, ANOVA and Lack-of-fit tests demonstrated that the regression equations were statistically significant (p<0.05), and the resulting linear model is fully adequate for both analytical methods. The LOD values were 0.09 and 0.01 mu g.mL(-1), while the LOCI were 0.27 and 0.04 mu g.mL(-1) for spectrophotometric and spectrofluorimetric methods, respectively. Repeatability and intermediate precision for proposed methods showed relative standard deviation (RSD) between 0.58% to 4.80%. The percent recovery ranged from 98.9% to 102.7% for spectrophotometric analyses and from 94.2% to 101.2% for spectrofluorimetry. No interferences from common excipients were detected and both methods were considered specific. Therefore, the methods are accurate, precise, specific, and reproducible and hence can be applied for quantification of CIAIPc in nanoemulsions (NE) and nanocapsules (NC).

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Autologous bone marrow mononuclear cell (BMMC) transplantation has emerged as a potential therapeutic option for refractory angina patients. Previous studies have shown conflicting myocardium reperfusion results. The present study evaluated safety and efficacy of CellPraxis Refractory Angina Cell Therapy Protocol (ReACT). in which a specific BMMC formulation was administered as the sole therapy for these patients. The phase I/IIa noncontrolled, open label. clinical trial, involved eight patients with refractory angina and viable ischemic myocardium, without left ventricular dysfunction and who were not suitable for conventional myocardial revascularization. ReACT is a surgical procedure involving a single series of multiple injections (40-90 injections, 0.2 ml each) into ischemic areas of the left ventricle. Primary endpoints were Canadian Cardiovascular Society Angina Classification (CCSAC) improvement at 18 months follow-up and myocardium ischemic area reduction (assessed by scintigraphic analysis) at 12 months follow-up, in correlation with a specific BMMC formulation. Almost all patients presented progressive improvement in angina classification beginning 3 months (p = 0.008) postprocedure which was sustained at 18 months follow-up (p = 0.004), as well as objective myocardium ischemic area reduction at 12 months (decrease of 84.4%, p < 0.004). A positive correlation was found between monocyte concentration and CCSAC improvement (r = -0.759, p < 0.05). Improvement in CCSAC, followed by correlated reduction in scintigraphic myocardium ischemic area, strongly suggests neoangiogenesis as the main stem cell action mechanism. The significant correlation between number of monocytes and improvement strongly supports a cell-related effect of ReACT. ReACT appeared safe and effective.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background There are occupational risks inherent to the activities of professional hairdressers, which are not frequently studied, and therefore not considered in the formulation of health policies for this group. Aims To verify the prevalence of work-related musculoskeletal disorders (WRMDs) in hairdressers through symptom reports, to characterize the most frequently affected anatomical parts and to identify and analyse risk factors of WRMDs in hairdressing. Methods A cross-sectional epidemiological study of 220 hairdressers from beauty parlours in Sao Paulo (Brazil) was carried out. Each hairdresser completed a self-administered questionnaire which included information on socio-demographic characteristics, working conditions and health-related musculoskeletal system complaints. Ergonomic analyses were also performed in six parlours. Results The prevalence of WRMDs was 71%. Risk factors were associated with psychosocial factors and factors related to discomfort and work fatigue such as lack of acknowledgement of work and uncomfortable posture at work [odds ratio (OR) = 3.54; 95% confidence interval (CI) 1.51-8.30], not feeling comfortable with body/neck/shoulders while working (OR = 2.78; 95% CI 1.40-5.54) and having > 15 years of professional activity (OR = 3.04; 95% CI 1.17-7.91). Conclusion Occupational risk factors associated with the development of WRMDs in hairdressers are related to biomechanical, organizational and psychosocial work factors. The high prevalence of WRMDs found highlights the importance of disseminating recommendations for prevention of symptoms with regards to the provision of suitable furniture, equipment and work tools, environmental conditions, size of workplace, work organization and psychosocial work factors.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background: Risperidone (RSP) is a benzisoxazole antipsychotic agent used to treat schizophrenia and other psychiatric illnesses in adults and children (including those with autism). After oral administration, RSP is completely absorbed from the gastrointestinal tract and undergoes hydroxylation to yield 9-hydroxyrisperidone (9-OH-RSP), an active metabolite that has a pharmacologic profile and potency similar to RSP. Objectives: The aims of this study were to compare the relative bioavailability of a pharmaceutical-equivalent (test) formulation with a reference formulation of oral RSP 2 mg, both available commercially on the Brazilian pharmaceutical market, and to generate data regarding the oral bioavailability of the tested drug in healthy Brazilian volunteers. Methods: This single-dose, randomized-sequence, open-label, 2-period crossover study was conducted in healthy Brazilian volunteers from August to December 2008. Subjects were randomly assigned to receive the test formulation followed by the reference formulation or vice versa, with a 30-day washout period between doses. Study drugs were administered after a 12-hour overnight fast. For pharmacokinetic analysis, blood samples were drawn at 0 (baseline), 0.25, 0.5, 1, 1.5, 3, 5, 8, 12, 24, 48, 72, 96, and 120 hours after administration. Plasma concentrations of RSP and 9-OH-RSP were determined using LC-MS/MS. The test and reference formulations were to be considered bioequivalent if the 90% CIs for the geometric mean test/reference ratios were within a predetermined range of 80% to 125%, in accordance with the policies of the Brazilian Sanitary Surveillance Agency and the US Food and Drug Administration. Tolerability was determined using clinical assessments, monitoring of vital signs, analysis of laboratory test results, and subject interviews regarding adverse events. Results: A total of 22 subjects were enrolled (11 men, 11 women; mean [SD] age, 32 [12] years [range, 18-58 years]; weight, 70.4 [11.9] kg [range, 50-103 kg]; height, 1.67 [0.08] m [range, 1.56-1.80 m]; and body mass index, 25 [4] kg/m(2) [range, 18-29 kg/m(2)]). For RSP, mean (SD) C(max) values were 12.6 (2.7) and 16.0 (2.3) ng/mL for the test and reference formulations, respectively. For 9-OH-RSP, mean C(max) values were 17.8 (1.3) and 21.0 (1.7) ng/mL for the test and reference formulations. The 90% CIs for the mean test/reference ratios for RSP C(max), AUC(0-120), and AUC(0-infinity) were 74% to 82%, 75% to 85%, and 76% to 85%, respectively, and 83% to 87%, 75% to 79%, and 75% to 78% for 9-OH-RSP. The related adverse events (headache, low back pain, drowsiness, standing hypotension, local postvenipuncture ecchymoses, insomnia, nausea, and vomiting) were transient and mild. Conclusions: This single-dose study found that the test and reference formulations of oral RSP 2 mg did not meet the Brazilian and US regulatory criteria for bioequivalence in these fasting, healthy volunteers. The study formulations appeared to be well tolerated. (Clin Ther 2010;32:2106-2115) (C) 2010 Elsevier HS Journals, Inc.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Drug delivery systems are promising pharmaceutical formulations used to improve the therapeutic index of drugs. In this study, we developed a liposomal formulation of furazolidone that targets Leishmania (Leishmania) chagasi amastigotes in a hamster model. Using laser scanning confocal microscopy, it was demonstrated that the liposomal drug co-localised with L. (L.) chagasi amastigotes within macrophages. Liposomal furazolidone administered intraperitoneally at 0.5 mg/kg for 12 consecutive days reduced spleen (74%) and liver (32%) parasite burden at a 100-fold lower dose than the free drug. Free furazolidone (50 mg/kg) also effectively reduced spleen (82.5%) and liver (85%) parasites; its in vitro activity against promastigotes and intracellular amastigotes demonstrated a high degree of parasite selectivity. Thus, furazolidone, both in the free and liposome-loaded formulation, is an effective inhibitor of L. (L.) chagasi, representing a possible cost-effective drug candidate for the treatment of visceral leishmaniasis. (C) 2010 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In this study, the photodynamic action of liposomes (LP) and nanocapsules (NC) containing Chloroaluminum phthalocyanine (CIAIPc), on the human melanoma cell (WM 1552C), was assessed. The light source was setup at 672 nm, which corresponds to the maximum absorption wavelength of the CIAIPc. Both colloidal carriers presented size in nanometric scale as well as negative zeta potential. The cellular damage was light dose dependent ranging from 30% of cell death at 70 mJ.cm(-2) to 90% of death at 700 mJ.cm(-2). However, the photocytotoxic effect of LP at 70 mJ.cm(-2) was slightly more efficient to induce cellular death than NC formulation. At 140 mJ.cm(-2), and 700 mJ.cm(-2) both nanocarriers were equally efficient to induce cellular damage. Therefore, in the present work, the maximum phototoxic effect was obtained with 700 mJ.cm(-2) of light dose, in combination with 0.29 mu g.mL(-1) of CIAIPc encapsulated into LP and NC. The cells were also positive to annexin V, after the PDT treatment with LP and NC, showing that one of the mechanisms of cellular death involved is apoptosis. In summary, the potential of LP and NC as a drug delivery system, in Photodynamic Therapy (PDT) against melanoma, has been confirmed using a lower concentration of the photosensitizer and lower light doses than that applied in current protocols. This is an innovative proposal to treat melanoma cell lines that until now have not received the benefit of the PDT protocol for treatment.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Introduction: Zinc is an essential element for human homeostasis being clearly related to almost all metabolic pathways. It is found in some neural circuitries, probably acting as a modulator of glutamatergic excitatory synapsis. In the auditory system its presence has been demonstrated within the cochlea and cochlear nuclei. Tinnitus symptoms are correlated to zinc physiology, and it has been postulated that the oligoelement could be used as an alternative treatment for this clinical situation. Aim: This study has evaluated the brainstem responses (ABR) in patients who suffer from chronic idiophatic tinnitus, before and after being treated with zinc. Neural transmissions in the brainstem auditory structures were also compared in both conditions. Materials and Methods: Forty-one patients (22 with tinnitus and 19 controls, groups I and II, respectively) were included in the study and submitted to anamnesis, otorhinolaryngologic examinations, biochemical evaluation and audiological tests. Group I patients received an specific zinc formulation for 90 days. ABR tests were performed at the beginning of the study and at the end of the zinc treatment. Results: First ABR tests showed no differences between the groups, but on the second evaluation there was a significant prolongation of the wave V latency and an enlargement of wave V amplitude shown in group I. Conclusion: Treatment with systemic zinc could change some aspects of auditory neurotransmission in the brainstem.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The present study investigated the potential use of topical formulations containing marigold extract (ME) (Calendula officinalis extract) against ultraviolet (UV) B irradiation-induced skin damage. The physical and functional stabilities, as well as the skin penetration capacity, of the different topical formulations developed were evaluated. In addition, the in vivo capacity to prevent/treat the UVB irradiation-induced skin damage, in hairless mice, of the formulation with better skin penetration capacity was investigated. All of the formulations were physically and functionally stable. The gel formulation [Formulation 3 (F3)] was the most effective for the topical delivery of ME, which was detected as 0.21 mu g/cm(2) of narcissin and as 0.07 mu g/cm(2) of the rutin in the viable epidermis. This formulation was able to maintain glutathione reduced levels close to those of nonirradiated animals, but did not affect the gelatinase-9 and myeloperoxidase activities increased by exposure to UVB irradiation. In addition, F3 reduced the histological skin changes induced by UVB irradiation that appear as modifications of collagen fibrils. Therefore, the photoprotective effect in hairless mice achieved with the topical application of ME in gel formulation is most likely associated with a possible improvement in the collagen synthesis in the subepidermal connective tissue. (C) 2010 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 100:2182-2193, 2011

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Introduction. Epilepsy is a condition characterized by signs and symptoms of neurological disorder. Lamotrigine has been widely used, mainly due to their greater tolerability and lower rate of drug interactions with other antiepileptic drugs however the newest antiepileptic drugs have high cost to patient. In Brazil there are three different sort of pharmaceutical equivalents (reference, generic and similar), and the Brazilian health care authorities offers to users the possibility to receive them free of charge. Moreover these pharmaceutical equivalents can change during the treatment of epilepsy because this authorities buy the cheapest by public tender two or three times a year. Aim. To evaluate the clinical and laboratory findings related to the most frequently used therapeutic equivalents of lamotrigine (reference drugs and similar products). Patients and methods. Two similar formulations (A and B) and one reference (C) were tested in nine epileptic refractory patients. The study was divided into three periods of 42 days, one for each formulation, and medical data about the frequency of seizures, the occurrence of side effects and measurement of plasma concentrations of lamotrigine were collected. Results. The average number of seizures/week and plasma concentration of lamotrigine for formulations A, B and C were not statistically significant differences. Three patients during the use of the formulation C presented mild and transitory side effects. Conclusion. Similar or reference drugs showed satisfactory results, however the interchangeability among the formulations raise the difficulty for the management of seizures in refractory epilepsy.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Purpose: To determine the influence of rate of polymerization, degree of conversion and volumetric shrinkage on stress development by varying the amount of photoinitiators in a model composite. Methods: Volumetric shrinkage (with a mercury dilatometer), degree of conversion, maximum rate of reaction (RP(max)) (with differential scanning calorimetry) and polymerization stress (with a controlled compliance device) were evaluated. Bis-GMA/TEGDMA (equal mass ratios) were mixed with a tertiary amine (EDMAB) and camphorqpinone, respectively, in three concentrations (wt%): high= 0.8/1.6; intermediate= 0.4/0.8 and low= 0.2/0.4. 80 wt% filler was added. Composites were photoactivated (400 mW/cm(2) x 40 seconds; radiant exposure=16J/cm(2)). A fourth experimental group was included in which the low concentration formulation was exposed for 80 seconds (32 J/cm(2)). Results: For the same radiant exposure, conversion, RP(max) and stress increased with photoinitiator concentration (P< 0.001). When the low concentration group exposed to 32 J/cm(2) was compared with the high and intermediate groups (exposed to 16 J/cm(2)), RPmax Still increased with the photoinitiator concentration between all levels (P< 0.001) but conversion and stress did not vary (P> 0.05). Shrinkage did not vary regardless of the photoinitiator concentration or radiant exposure. For the photoinitiator concentrations used in this study. Polymerization stress was influenced by conversion but not by rate of reaction. (Am J Dent 2009;22:206-210).

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Different monomer structures lead to different physical and mechanical properties for both the monomers and the polymers. The objective of this study was to determine the influence of the bisphenylglycidyl dimethacrylate (BisGMA) concentration (33, 50 or 66 mol%) and the co-monomer content [triethylene glycol dimethacrylate (TEGDMA), ethoxylated bisphenol-A dimethacrylate (BisEMA), or both in equal parts] on viscosity (eta), degree of conversion (DC), and flexural strength (FS). eta was measured using a viscometer, DC was obtained by Fourier transfer Raman (FT-Raman) spectroscopy, and FS was determined by three-point bending. At 50 and 66% BisGMA, increases in eta were observed following the partial and total substitution of TEGDMA by BisEMA. For 33% BisGMA, eta increased significantly only when no TEGDMA was present. The DC was influenced by BisGMA content and co-monomer type. Mixtures containing 66% BisGMA showed a lower DC compared with mixtures containing other concentrations of BisGMA. The BisEMA mixtures had a lower DC compared with the TEGDMA mixtures. The FS was influenced by co-monomer content only. BisEMA mixtures presented a statistically lower FS, followed by TEGDMA + BisEMA mixtures, and then by TEGDMA mixtures. Partial or total replacement of TEGDMA by BisEMA increased eta, which was associated with the observed decreases in DC and FS. Although the BisGMA content influenced the DC, it did not affect the FS results.