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1.
J Med Econ ; 25(1): 630-639, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35510376

RESUMO

AIM: This post-hoc analysis estimated annual indirect cost savings with galcanezumab (GMB) treatment in patients with episodic migraine (EM) or chronic migraine (CM). METHODS: Data from 4 randomized, Phase 3, double-blind (DB), placebo (PBO)-controlled studies of GMB were analyzed: EVOLVE-1 and EVOLVE-2 (EM, 6-months DB), REGAIN (CM, 3-months DB), and CONQUER (previous failure of 2-4 migraine preventive medication categories, 3-months DB). Indirect costs were calculated at baseline and Month 3 using the first 2 items in Migraine Disability Assessment (MIDAS): (A + B)/60*country specific annual wage (A = days of missed work/school; B = days of reduced productivity at work/school; assuming 60 working days in 3 months). All costs were annualized and expressed in international dollars (Int$) in 2018. ANCOVA models estimated the indirect cost savings as a change from baseline. Secondary analyses determined cost savings by employment and responder status. RESULTS: Patients (>80% females) from EVOLVE-1 and -2 (n = 1,201; mean age 41.9 years), REGAIN (n = 759; mean age 41.3 years), and CONQUER (n = 453; mean age ∼46.0 years) were analyzed. GMB showed significant indirect cost savings for EM (Int$6256, p < .0001) and CM (Int$7129, p = .0002), with substantial savings for patients with previous failure of 2-4 migraine preventive medication categories (EM: Int$5664, p = .0030; CM: Int$5181, p = .1300). Compared with PBO, GMB showed significantly greater indirect cost savings for EM (p = .0156) and patients with previous failure of 2-4 migraine preventive medication categories (p = .0340). Employed patients with CM (p = .0018) and with previous failure of 2-4 migraine preventive medication categories (p < .0001) had significant cost savings after GMB treatment. GMB showed significant indirect cost savings in patients with a reduction in migraine headache days. CONCLUSION: GMB treatment resulted in annual indirect cost savings in patients with EM, CM, and with previous failure of 2-4 migraine preventive medication categories, with similar observations in the sensitivity analyses.


Assuntos
Transtornos de Enxaqueca , Adulto , Anticorpos Monoclonais Humanizados/uso terapêutico , Redução de Custos , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos de Enxaqueca/tratamento farmacológico , Transtornos de Enxaqueca/prevenção & controle , Resultado do Tratamento
2.
Eur J Pharm Biopharm ; 160: 82-91, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33503492

RESUMO

Solid lipid nanoparticles (SLNs) are presently being promoted to improve bioavailability of encapsulated drugs. These are well tolerated in living systems, as they are made from biocompatible material. Despite finding extensive applicability, these systems have not been sufficiently investigated for the toxicity so far. We have reported use of SLNs to improve plasma bioavailability of isoniazid (INH), a hepatotoxic, antitubercular drug. Presently we evaluate acute and repeated (28-day) oral dose toxicity, with satellite group, of developed INH loaded COMBI-SLN. In addition to high bioavailability, the COMBI-SLN exhibited 3 times higher LD50 (2000 mg/kg BW) versus 650 mg/kg BW for free INH. Results were complemented with histopathological evidence in brain, sciatic nerve and liver tissue all of which indicated enhanced safety of INH upon incorporation into SLNs. In the repeated dose study at doses selected as per Organisation for Economic Co-operation and Development (OECD) guidelines, a series of behavioural and haematological tests, clinical biochemistry (kidney and liver function, lipid profile) and histopathological studies were performed to evaluate the effect of low (250 mg/kg BW), medium (500 mg/kg BW) and high oral dose (1000 mg/kg BW). Absence of adverse effects like hepatotoxicity and peripheral neuropathy observed in rats at an oral intake level of 500 and 1000 mg/kg BW of COMBI-SLN, that is 20-40 folds above the anticipated human intake levels (after normalizing the surface area correction for rats), supports the conclusion that SLN are an intrinsically safe nanocarrier system that improves both the efficacy and the safety of INH.


Assuntos
Antituberculosos/toxicidade , Portadores de Fármacos/toxicidade , Isoniazida/toxicidade , Nanopartículas/toxicidade , Administração Oral , Animais , Antituberculosos/administração & dosagem , Antituberculosos/farmacocinética , Disponibilidade Biológica , Relação Dose-Resposta a Droga , Portadores de Fármacos/química , Feminino , Isoniazida/administração & dosagem , Isoniazida/farmacocinética , Dose Letal Mediana , Lipídeos/química , Lipídeos/toxicidade , Masculino , Nanopartículas/química , Organização para a Cooperação e Desenvolvimento Econômico/normas , Tamanho da Partícula , Ratos , Testes de Toxicidade Aguda/normas
3.
Headache ; 61(3): 511-526, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33481276

RESUMO

OBJECTIVE: To evaluate the measurement properties of all three domains of the Migraine-Specific Quality of Life questionnaire version 2.1 (MSQ v2.1) electronic patient-reported outcome (ePRO) to assess the functional impact of migraine in patients with episodic or chronic migraine (CM); and identify meaningful within-patient change thresholds for the Role Function-Restrictive (RFR), Role Function-Preventive (RFP), and Emotional Function (EF) domains. METHODS: Data were drawn from three double-blind, placebo-controlled, and randomized Phase 3 clinical studies (episodic migraine [EM]: EVOLVE-1 and EVOLVE-2; CM: REGAIN). The psychometric properties of the MSQ v2.1 ePRO domains were demonstrated by evaluating reliability (internal consistency and test-retest), construct validity (convergent and known groups), and responsiveness. Meaningful within-patient change thresholds for domains were estimated using anchor-based approaches, supplemented by empirical cumulative distribution function curves and probability density function plots to enable interpretation of meaningful change over 3 months. The Patient Global Impression of Severity (PGI-S) and Patient Global Impression of Improvement served as anchors. RESULTS: A total of 2,850 patients with either EM (EVOLVE-1: 851; EVOLVE-2: 909) or CM (REGAIN: 1,090) were included. The Cronbach's alpha estimates of internal consistency exceeded the recommended threshold of ≥0.70 for all domains from the three studies, indicating adequate internal consistency. Test-retest reliability intraclass correlation coefficients were ≥0.80 for all domains across all three studies, demonstrating almost perfect agreement. Convergent validity was supported by moderate-to-strong correlation (r ≥ 0.30) between all domains of MSQ v2.1 ePRO and studied anchors (Migraine Disability Assessment Score and PGI-S scores) across all three studies. Known group validity was established between all domains and subgroups of patients stratified by baseline PGI-S scores and baseline number of monthly migraine headache days for all three studies. The 3-month meaningful within-patient change thresholds were the same for EM and CM for RFP: 20.00 and EF: 26.67; and for RFR: 25.71. CONCLUSIONS: These findings demonstrate that all three domains of the MSQ v2.1 ePRO have sufficient reliability, validity, responsiveness, and appropriate interpretation standards. Our results suggest that MSQ v2.1 ePRO is a well-defined and reliable patient-reported outcome instrument that is suitable for use in clinical studies for evaluating the impact of migraine on patient functioning in episodic and CM.


Assuntos
Medidas de Resultados Relatados pelo Paciente , Psicometria/instrumentação , Psicometria/normas , Qualidade de Vida , Adolescente , Adulto , Idoso , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos de Enxaqueca , Inquéritos e Questionários/normas , Adulto Jovem
4.
BMC Neurol ; 20(1): 194, 2020 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-32429851

RESUMO

BACKGROUND: Injection-site reactions have been reported with biologicals. In this post hoc analysis of Phase 3 studies in participants with migraine, we provide a comprehensive overview and detailed summary of injection-site reaction with galcanezumab. METHODS: Data were obtained from two randomised clinical studies in participants with episodic migraine (EVOLVE-1 and EVOLVE-2), one randomised study in participants with chronic migraine (REGAIN) and one open-label study (Study CGAJ) in participants with episodic or chronic migraine. The injection-site reactions were measured for two different cohorts: 1) six-month double-blind treatment phase in the EVOLVE-1 and EVOLVE-2 studies and three-month double-blind treatment phase in the REGAIN study, where participants received placebo and galcanezumab (placebo-controlled analysis set); 2) three month double-blind (Month 0 to Month 3; 1:1:placebo:galcanezumab) + 9 months open-label extension phase (Month 3 to Month 12) of REGAIN and twelve month open-label phase of Study CGAJ, where participants received only galcanezumab (galcanezumab exposure analysis set). RESULTS: A total of 477 participants in the placebo-controlled analysis set (galcanezumab 240 mg, 166/730 [22.7%]; galcanezumab 120 mg, 128/705 [18.2%]; placebo, 183/1451 [12.6%]) reported at least one injection-site reaction. Most of the injection-site reactions were reported as injection-site pain, unspecified injection-site reaction, injection-site erythema, and injection-site pruritus. The incidence of injection-site pain was highest among all reported injection-site reactions and were reported with similar frequency by participants receiving galcanezumab (galcanezumab 120 mg, 10.1%; galcanezumab 240 mg, 11.6%) and placebo (9.5%) and was the most common injection-site reaction reported within 60 min of injection (~ 86% of participants). The frequency of unspecified injection-site reaction, injection-site erythema and injection-site pruritus was significantly (P < 0.001) higher in participant receiving galcanezumab versus placebo. In the galcanezumab exposure analysis set participants received up to 12 doses and the frequency of injection-site reactions reported for both doses combined was 21.8%. The reporting of injection-site reactions did not increase with the number of doses received. No ISR-related serious adverse events were reported in both the placebo-controlled and galcanezumab exposure analysis sets. CONCLUSIONS: The most common adverse event of galcanezumab is injection-site reactions. However, these events were generally mild-to-moderate in severity, non-serious, resolved spontaneously, and discontinuations due to injection-site reactions were low (1%).


Assuntos
Anticorpos Monoclonais Humanizados/administração & dosagem , Transtornos de Enxaqueca/tratamento farmacológico , Dor/etiologia , Adulto , Anticorpos Monoclonais Humanizados/efeitos adversos , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
5.
J Appl Polym Sci ; 137(37)2020 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-34305166

RESUMO

In this work, the development of novel magnetic nanocomposite microparticles (MNMs) via free radical polymerization for their application in the remediation of contaminated water is presented. Acrylated plant-based polyphenols, curcumin multiacrylate (CMA) and quercetin multiacrylate (QMA), were incorporated as functional monomers to create high affinity binding sites for the capture of polychlorinated biphenyls (PCBs), as a model pollutant. The MNMs were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, dynamic light scattering, and UV-visible spectroscopy. The affinity of these novel materials for PCB 126 was evaluated and fitted to the nonlinear Langmuir model to determine binding affinities (K D). The results suggest the presence of the polyphenolic moieties enhances the binding affinity for PCB 126, with K D values comparable to that of antibodies. This demonstrates that these nanocomposite materials have promising potential as environmental remediation adsorbents for harmful contaminants.

6.
Mater Chem Phys ; 223: 68-74, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31452560

RESUMO

In this work, we developed novel core-shell nanoparticle systems with magnetic core and polymer shell via atom transfer radical polymerization for use as high affinity nanoadsorbents for organic contaminants in water and wastewater treatment. Polyphenolic-based moieties, curcumin multiacrylate (CMA) and quercetin multiacrylate (QMA), were incorporated into poly(ethylene glycol) (PEG) based polymeric shells to create high affinity binding sites for the capture of polychlorinated biphenyls (PCBs) as a model pollutant. The resulting magnetic nanoparticles (MNPs) were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), X-ray diffraction (XRD), dynamic light scattering (DLS), and UV-visible spectroscopy. The affinity of these novel materials for PCB 126 was evaluated and fitted to the nonlinear Langmuir model to determine binding affinities (KD). The KD values obtained were: PEG MNPs (8.42 nM) < IO MNPs (8.23nM) < QMA MNPs (5.88 nM) < CMA MNPs (2.72 nM), demonstrating that the presence of polyphenolic-based moieties enhanced PCB 126 binding affinity, which is hypothesized to be a result of π - π stacking interactions. These values are lower that KD values for activated carbon, providing strong evidence that these novel core-shell nanoparticles have a promising application as nanoadsorbents for specific organic contaminants offering a cost effective alternative to current remediation approaches.

7.
BMJ Case Rep ; 12(7)2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31296618

RESUMO

Native right coronary artery (RCA) spasm is a less frequent early complication of perioperative coronary artery bypass grafting. Late presentation at 6 days postoperation is scarce and its relationship with an anomalous coronary artery is unknown. The optimal management and prevention remains controversial. In the case presented, the patient's anomalous left coronary artery originating from the right coronary cusp underwent ligation at its proximal segment at the time of bypass grafting. This ligation was preformed to prevent competitive flow. Six days postoperation, a refractory spasm of dominant native RCA occurred. The spasm resulted in right ventricular failure. Administration of intracoronary verapamil had a longer sustained vasodilatory effect and resolution of coronary spasm when compared with intracoronary nitroglycerine injection. An intra-aortic balloon pump, inotropic agents and low-dose nitroglycerine were used to maintain adequate haemodynamic support. Right ventricular systolic function recovery was noted within 2 days postintervention.


Assuntos
Ponte de Artéria Coronária , Vasoespasmo Coronário/complicações , Vasoespasmo Coronário/diagnóstico por imagem , Anomalias dos Vasos Coronários/complicações , Complicações Pós-Operatórias/diagnóstico por imagem , Cardiotônicos/uso terapêutico , Angiografia por Tomografia Computadorizada , Angiografia Coronária , Ponte de Artéria Coronária sem Circulação Extracorpórea , Vasoespasmo Coronário/tratamento farmacológico , Vasos Coronários/diagnóstico por imagem , Feminino , Humanos , Pessoa de Meia-Idade , Nitroglicerina/uso terapêutico , Complicações Pós-Operatórias/tratamento farmacológico , Vasodilatadores/uso terapêutico , Verapamil/uso terapêutico
8.
Mater Today Commun ; 10: 46-53, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28989952

RESUMO

Two series of thermosensitive hydrogels were synthesized by copolymerizing N-isopropylacrylamide (NIPAAm) with various contents of novel hydrophobic crosslinkers, curcumin multiacrylate (CMA) and quercetin multiacrylate (QMA). The compositions of the resulting hydrogels were characterized using solid state-NMR (ss-NMR), and the temperature dependent swelling behavior and lower critical solution temperature (LCST) were characterized using swelling studies and differential scanning calorimetry (DSC). Increasing the crosslinker content resulted in a significant decrease in the LCST and swelling ratio of hydrogels, which could be attributed to the increased hydrophobicity introduced by CMA or QMA. All of the hydrogels demonstrated temperature responsive swelling with the extent of swelling decreasing with increasing crosslinker content. The lower crosslinker content gels displayed sharper phase transitions, while the high crosslinker content gels had broader phase transitions.

9.
Gels ; 3(4)2017.
Artigo em Inglês | MEDLINE | ID: mdl-29805968

RESUMO

A series of novel temperature responsive hydrogels were synthesized by free radical polymerization with varying content of chrysin multiacrylate (ChryMA). The goal was to study the impact of this novel polyphenolic-based multiacrylate on the properties of N-isopropylacrylamide (NIPAAm) hydrogels. The temperature responsive behavior of the copolymerized gels was characterized by swelling studies, and their lower critical solution temperature (LCST) was characterized through differential scanning calorimetry (DSC). It was shown that the incorporation of ChryMA decreased the swelling ratios of the hydrogels and shifted their LCSTs to a lower temperature. Gels with different ChryMA content showed different levels of response to temperature change. Higher content gels had a broader phase transition and smaller temperature response, which could be attributed to the increased hydrophobicity being introduced by the ChryMA.

10.
ACS Omega ; 2(12): 8723-8729, 2017 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-29302630

RESUMO

A novel crosslinker [4,4'-dihydroxybiphenyl diacrylate (44BDA)] was developed, and a series of temperature-responsive hydrogels were synthesized through free radical polymerization of N-isopropylacrylamide (NIPAAm) with 44BDA. The temperature-responsive behavior of the resulting gels was characterized by swelling studies, and the lower critical solution temperature (LCST) of the hydrogels was characterized through differential scanning calorimetry. Increased content of 44BDA led to a decreased swelling ratio and shifted the LCST to lower temperatures. These novel hydrogels also displayed resiliency through multiple swelling-deswelling cycles, and their temperature responsiveness was reversible. The successful synthesis of NIPAAm-based hydrogels crosslinked with 44BDA has led to a new class of temperature-responsive hydrogel systems with a variety of potential applications.

11.
Emerg Med Int ; 2016: 6983750, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27379186

RESUMO

The American Heart Association reports the annual incidence of out-of-hospital cardiopulmonary arrests (OHCA) is greater than 300,000 with a survival rate of 9.5%. Bystander cardiopulmonary resuscitation (CPR) saves one life for every 30, with a 10% decrease in survival associated with every minute of delay in CPR initiation. Bystander CPR and training vary widely by region. We conducted a retrospective study of 320 persons who suffered OHCA in South Florida over 25 months. Increased survival, overall and with bystander CPR, was seen with increasing income (p = 0.05), with a stronger disparity between low- and high-income neighborhoods (p = 0.01 and p = 0.03, resp.). Survival with bystander CPR was statistically greater in white- versus black-predominant neighborhoods (p = 0.04). Increased survival, overall and with bystander CPR, was seen with high- versus low-education neighborhoods (p = 0.03). Neighborhoods with more high school age persons displayed the lowest survival. We discovered a significant disparity in OHCA survival within neighborhoods of low-income, black-predominance, and low-education. Reduced survival was seen in neighborhoods with larger populations of high school students. This group is a potential target for training, and instruction can conceivably change survival outcomes in these neighborhoods, closing the gap, thus improving survival for all.

12.
Mater Sci Eng C Mater Biol Appl ; 67: 59-64, 2016 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-27287099

RESUMO

Magnetic iron oxide nanoparticles have been well known for their applications in magnetic resonance imaging (MRI), hyperthermia, targeted drug delivery, etc. The surface modification of these magnetic nanoparticles has been explored extensively to achieve functionalized materials with potential application in biomedical, environmental and catalysis field. Herein, we report a novel and versatile single step methodology for developing curcumin functionalized magnetic Fe3O4 nanoparticles without any additional linkers, using a simple coprecipitation technique. The magnetic nanoparticles (MNPs) were characterized using transmission electron microscopy, X-ray diffraction, fourier transform infrared spectroscopy and thermogravimetric analysis. The developed MNPs were employed in a cellular application for protection against an inflammatory agent, a polychlorinated biphenyl (PCB) molecule.


Assuntos
Curcumina , Portadores de Fármacos , Óxido Ferroso-Férrico , Células Endoteliais da Veia Umbilical Humana/metabolismo , Nanopartículas de Magnetita/química , Curcumina/química , Curcumina/farmacocinética , Curcumina/farmacologia , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Portadores de Fármacos/farmacologia , Óxido Ferroso-Férrico/química , Óxido Ferroso-Férrico/farmacocinética , Óxido Ferroso-Férrico/farmacologia , Humanos , Nanopartículas de Magnetita/ultraestrutura , Tamanho da Partícula , Bifenilos Policlorados/toxicidade
13.
Cholesterol ; 2015: 292935, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26617998

RESUMO

Background. The American College of Cardiology and American Heart Association did not indicate a correlation between treating hypertriglyceridemia and reducing cardiovascular events. Objective. This study investigated whether patients with hypertriglyceridemia were more prone to worse outcomes during cardiac catheterization. Methods. Data collected over a one-year period analyzed lipid panels obtained at the time of cardiac catheterization. Triglyceride levels were categorized into three groups: <150 mg/dL, 150 mg/dL-300 mg/dL, and >300 mg/dL. Controlled variables included age, gender, the presence of hypertension, diabetes, hyperlipidemia, and history of coronary artery disease. Results. Subjects with a triglyceride level <150 mg/dL have a 54% likelihood of being treated medically compared to 38% and 41% in the 150 mg/dL-300 mg/dL and >300 mg/dL groups, respectively (p < 0.01). Subjects with a triglyceride level >300 mg/dL have a 20% percent chance of being treated with a coronary artery bypass graft compared to 12% and 15% in the <150 mg/dL and 150 mg/dL-300 mg/dL groups, respectively (p < 0.01). Subjects with a triglyceride level between 150 and 300 mg/dL have a 44% percent of being treated with a percutaneous coronary intervention compared to 34% and 43% in the <150 mg/dL and >300 mg/dL groups, respectively (p < 0.01). Conclusion. Hypertriglyceridemia was associated with worse outcomes in percutaneous coronary intervention or surgery.

14.
Langmuir ; 31(23): 6570-6, 2015 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-26039456

RESUMO

The synthesis and characterization of Sn nanoparticles in organic solvents using sixth-generation dendrimers modified on their periphery with hydrophobic groups as stabilizers are reported. Sn(2+):dendrimer ratios of 147 and 225 were employed for the synthesis, corresponding to formation of Sn147 and Sn225 dendrimer-stabilized nanoparticles (DSNs). Transmission electron microscopy analysis indicated the presence of ultrasmall Sn nanoparticles having an average size of 3.0-5.0 nm. X-ray absorption spectroscopy suggested the presence of Sn nanoparticles with only partially oxidized surfaces. Cyclic voltammetry studies of the Sn DSNs for Li alloying/dealloying reactions demonstrated good reversibility. Control experiments carried out in the absence of DSNs clearly indicated that these ultrasmall Sn DSNs react directly with Li to form SnLi alloys.

15.
Int J Pharm ; 446(1-2): 106-11, 2013 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-23410991

RESUMO

Rifampicin (RIF), a vital constituent of antitubercular therapy, hydrolyzes at the acidic pH of the stomach. The degradation is further enhanced by its interaction with Isoniazid (INH). Extent of RIF decomposition, in the presence and absence of INH, was determined at pH 1.2 (pH of empty stomach) at 37°C for 4 h (maximum stomach residence time). Both the drugs decomposed at gastric pH (26.5% and 1.43% for RIF and INH respectively). Considering that solid lipid nanoparticles (SLNs) avert drug-drug interaction and also drug degradation, we incorporated RIF into SLNs. Latter reduced its degradation to ~9% (from 26.50% when present alone) and to ~20% (from 48.81% when INH was also present). Subsequent to this, we also incorporated INH into SLNs and the percent degradation of RIF in this combination (RIF SLNs+INH SLNs) further reduced to 12.35%. Furthermore, the degradation of INH in combination with RIF also reduced significantly from 13.2% to 2.7% when both the drugs were encapsulated individually within SLNs. Study therefore highlights the need to develop combinations of antitubercular drugs (ATDs) with caution and also establishes the usefulness of nanoparticulate technology to avoid drug-drug interaction.


Assuntos
Antituberculosos/química , Portadores de Fármacos/química , Isoniazida/química , Nanopartículas/química , Rifampina/química , Varredura Diferencial de Calorimetria , Interações Medicamentosas , Estabilidade de Medicamentos , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Transmissão , Solubilidade
16.
Int J Pharm ; 441(1-2): 202-12, 2013 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-23220081

RESUMO

Low levels of isoniazid gain access into plasma following oral administration due to its high aqueous solubility, poor permeability and rapid and extensive hepatic metabolism. Further, a small t(1/2) of 1-4 h indicates its short stay in plasma and the need for repetitive or high doses which may subsequently result in hepatotoxicity and neurotoxicity associated with its use. Isoniazid-solid lipid nanoparticles (SLNs) were prepared to achieve improved bioavailability and prolonged effect, thus minimizing pulsatile plasma concentrations (and associated side effects at peak plasma concentrations). Developed SLNs showed high entrapment efficiency (69%) and small size (d(90) 48.4 nm) such that they are expected to bypass reticulo-endothelial system (RES) pickup resulting in prolonged circulation times and since liver is the major site of metabolism of isoniazid, RES avoidance will reduce its elimination from the body. Single dose (25 mg/kg BW) oral pharmacokinetic studies were performed in plasma and various tissues of rats. A significant improvement (p<0.001) in relative bioavailability in plasma (6 times) and brain (4 times) was observed after administration of isoniazid-SLNs with respect to the free drug solution at the same dose. Insignificant changes in liver concentration coupled with bypass of first pass metabolism and slow release of isoniazid (60%, in 24 h) indicate low incidence of hepatotoxicity. Isoniazid-SLNs showed a 3 times higher LD50.


Assuntos
Antituberculosos/farmacocinética , Isoniazida/farmacocinética , Lipídeos/química , Nanopartículas , Administração Oral , Animais , Antituberculosos/administração & dosagem , Antituberculosos/toxicidade , Disponibilidade Biológica , Encéfalo/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Preparações de Ação Retardada , Feminino , Isoniazida/administração & dosagem , Isoniazida/toxicidade , Dose Letal Mediana , Tamanho da Partícula , Ratos , Ratos Wistar , Distribuição Tecidual
17.
Langmuir ; 28(21): 8110-9, 2012 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-22591186

RESUMO

Advances in nanotechnology have indicated that the passivant and the inorganic surface play a pivotal role in controlling the structure/function relationship of materials. Beyond standard materials-based methods, bioligands have recently demonstrated the production of unique nanomaterial morphologies for application under ambient conditions for multiple activities, such as catalysis and biosensing. We have recently demonstrated that a biotemplate technique could be employed to produce spherical and linear Pd nanostructures in water using a self-assembling peptide framework. The materials possessed high catalytic reactivity that was controlled by the three-dimensional structure of the composite materials. To investigate the effect of the peptide template on the reactivity of Pd nanostructures, an in depth analysis of the catalytic activity of Pd nanostructures fabricated via truncated templates is presented. The new templates were designed from portions of the original framework, which demonstrated unique synthetic and functionality control. Two different reactions, Stille C-C coupling and 4-nitrophenol reduction, were employed to ascertain the effect of template structure on the reactivity of synthesized Pd nanomaterials via changes in reagent diffusion through the bioscaffold. The results indicate that the peptide framework plays an important role and could be used to tune and optimize the functionality of the final composite materials for the target application.


Assuntos
Materiais Biomiméticos/química , Nanopartículas Metálicas/química , Nanotecnologia , Paládio/química , Peptídeos/química , Estrutura Molecular , Tamanho da Partícula , Propriedades de Superfície
18.
J Control Release ; 127(2): 97-109, 2008 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-18313785

RESUMO

Brain is a delicate organ, isolated from general circulation and characterized by the presence of relatively impermeable endothelial cells with tight junctions, enzymatic activity and the presence of active efflux transporter mechanisms (like P-gp efflux). These formidable obstacles often impede drug delivery to the brain. As a result several promising molecules (showing a good potential in in vitro evaluation) are lost from the market for a mere consequence of lack of in vivo response probably because the molecule cannot reach the brain in a sufficient concentration. The options to tailor make molecules for brain, though open to the medical chemist, are a costly proposition in terms of money, manpower and time (almost 50 years). The premedial existing approaches for brain delivery like superficial and ventricular application of chemical or the application of chemicals to brain parenchyma are invasive and hence are less patient friendly, more laborious and require skill and could also damage the brain permanently. In view of these considerations novel drug delivery systems such as the nanoparticles are presently being explored for their suitability for targeted brain delivery. Nanoparticles are solid colloidal particles ranging in size from 1 to 1000 nm (<1 microm) and composed of macromolecular material. Nanoparticles could be polymeric or lipidic (SLNs). SLNs are taken up readily by the brain because of their lipidic nature. The bioacceptable and biodegradable nature of SLNs makes them less toxic as compared to polymeric nanoparticles. Supplemented with small size which prolongs the circulation time in blood, feasible scale up for large scale production and absence of burst effect makes them interesting candidates for study. In the present review we will discuss about the barriers to CNS drug delivery, strategies to bypass the blood-brain barrier and characterization methods of SLNs and their usefulness. The proposed mechanism of uptake, methods of prolonging the plasma retention and the in vivo and in vitro methods for assessment will also be discussed in some details.


Assuntos
Barreira Hematoencefálica/metabolismo , Fármacos do Sistema Nervoso Central/farmacocinética , Sistemas de Liberação de Medicamentos , Lipídeos/farmacocinética , Nanopartículas , Animais , Humanos
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