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1.
Pediatr Dent ; 46(3): 169-178, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38822500

RESUMO

Purpose: The purpose of this study was to perform a systematic review to assess current evidence for the association between child temperament and early childhood caries (ECC). Methods: A systematic search was conducted using MEDLINE?? through PubMed®, EMBASE®, Scopus®, LILACS, Web of Science™, and EBSCO up to January 2023. Studies measuring ECC and child temperament for children younger than or equal to six years of age using questionnaires, interviews, and surveys through case-control studies, cohort studies, and cross-sectional studies were included. Literature reviews were excluded. Medical subject heading (MeSH) terms like "temperament" and "dental caries" were used by two authors who independently extracted the data, and a third author resolved disagreements. Risk of bias assessment was done using the Newcastle-Ottawa assessment scale for case-control and cohort studies and the Appraisal tool for Cross-Sectional Studies (AXIS). The quality of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluations approach (GRADE approach). A chi-square test and I-square index were used to evaluate heterogeneity. Results: A total of 5,072 records were screened, resulting in 15 included studies that yielded data for 6,667 participants; sevenstudies were high, and eight were of moderate quality. Seven studies qualified for meta-analysis, which revealed that persistence did not affectthe presence or absence of ECC. However, there was a strong association between difficult temperament and ECC (odds ratio equals 2.63). Conclusion: A positive association between a child???s temperament and early childhood caries exists that is supported by quantitative findings, indicating a connection with very low certainty.


Assuntos
Cárie Dentária , Temperamento , Humanos , Pré-Escolar , Criança
2.
Evid Based Dent ; 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38605151

RESUMO

OBJECTIVE: Discolouration of primary teeth, often attributed to trauma and pulpal infection, is a prevalent concern that can significantly impact the esthetics and self-esteem of children. To address this issue, bleaching techniques have emerged as a viable treatment option. This systematic review aims to provide a comprehensive summary of the effectiveness of bleaching agents in managing discoloured primary teeth. METHODS: Two reviewers independently conducted an electronic database search using PubMed, EMBASE, LILACS, CINAHL via EBSCO, Scopus, and Web of Science until September 26,2023. In vitro studies and case reports that assessed the quantifiable success were included. The present review utilized Distiller SR software for data extraction. The protocol of this study was registered in PROSPERO (International Prospective Register of Systematic Reviews) (CRD42022329831). The quality of studies was analysed with Cochrane tool and the JBI checklist. RESULTS: The search retrieved 1845 references of which 14 studies were included for qualitative analysis. There were 8 in vitro studies and 6 case reports included in this systematic review. There were 299 teeth samples in the in vitro studies and 18 teeth were assessed in the case reports. All the 18 teeth (6 case reports) showed considerable shade improvement within 7-14 days. However, only 3 teeth were followed up for a period of 12-24 months. Substantial shade improvement was also observed in samples in the in vitro studies. CONCLUSION: This systematic review has comprehensively examined the various bleaching agents and methods for the management of discoloured primary teeth. However, it is crucial to recognize that the available evidence is from case reports and is insufficient to make a clinical recommendation.

3.
Phys Chem Chem Phys ; 26(13): 10191-10201, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38497147

RESUMO

Defects and disorder work as controlling parameters to alter the electronic structure of nanostructures and significantly influence their electronic, magnetic, and nonlinear optical (NLO) properties. In this study, we found that defect engineering is an effective strategy for tailoring the linear and nonlinear optical properties of Cu-doped titanium oxide (TiO2) flower-shaped nanostructures. The concentration of chemical doping of Cu in the TiO2 lattice creates intermediate defect states that impact electronic bandgap reduction and tunable defect luminescence. The estimation of the bandgap from density functional theory calculation follows the same trend of bandgap narrowing with Cu doping. The XPS study reveals that oxygen defects are responsible for bandgap narrowing and quenching of the PL intensity. A single-beam Z-scan technique with open and closed aperture configurations using ultrashort pulses centered at 532 nm excitation wavelength was used to study the NLO measurements. The open aperture reveals saturable absorption, whereas the closed aperture shows self-focusing behavior. The nonlinear absorption coefficient and refractive index extracted from NLO measurements demonstrate the linear dependence on the defect concentration and bandgap. The effects of heterogeneous dopants and lattice disorder on the nonlinear absorption behavior of these nanostructures are discussed in comparison with the figure of merit, non-linear refractive index, and absorption coefficient. The tunable NLO properties achieved by controlling such dopant-induced defects boost the scope of these nanostructures as optical limiting, optical switching, and optical photodiode applications.

4.
Nanotechnology ; 35(10)2023 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-38064734

RESUMO

The combination of 2D materials and noble metallic nanostructure is becoming an attractive research domain for label-free, highly sensitive surface-enhanced Raman spectroscopy (SERS) applications. This study demonstrated photocatalysis degradation and SERS enhancements of organic fluorophore (Rhodamine 6G) on two-dimensional (2D) TiSe2using Raman spectroscopy. The Au nanoparticles (NPs) were decorated on TiSe2thin films by thermal annealing at variable temperatures. The selective deposition of Au NPs on the hexagonal TiSe2nanocrystals increases surface roughness, creating a larger surface area for molecule adsorption. It has been observed that the Au decoration at 250 °C on TiSe2exhibits efficient detection capabilities for R6G with the Raman intensity enhancement factors of the order of ≈105along with the significantly improved visible light-induced photodegradation efficiency. The optimized Au NP size creates large electromagnetic hot spots produced by strong plasmon coupling that assists in the charge transfer mechanism among TiSe2, Au NPs, and R6G for enhanced SERS and photocatalysis activities. It has been observed that the intensity of Raman scattering decreases as the Au NP size increases on the TiSe2material. A possible charge transfer mechanism is proposed with an energy band diagram. The simultaneous measurement of SERS and photocatalytic dye degradation in Au decorated TiSe2can be used as a sensitive technique for water pollution treatment and biodegradable organic contaminants for the environmental ecosystem.

5.
Cell Rep ; 42(9): 113064, 2023 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-37656625

RESUMO

Dominant-negative mutations can help to investigate the biological mechanisms and to understand the selective pressures for multifunctional proteins. However, most studies have focused on recessive mutant effects that occur in the absence of a second functional gene copy, which overlooks the fact that most eukaryotic genomes contain more than one copy of many genes. We have identified dominant effects on yeast growth rate among all possible point mutations in ubiquitin expressed alongside a wild-type allele. Our results reveal more than 400 dominant-negative mutations, indicating that dominant-negative effects make a sizable contribution to selection acting on ubiquitin. Cellular and biochemical analyses of individual ubiquitin variants show that dominant-negative effects are explained by varied accumulation of polyubiquitinated cellular proteins and/or defects in conjugation of ubiquitin variants to ubiquitin ligases. Our approach to identify dominant-negative mutations is general and can be applied to other proteins of interest.


Assuntos
Proteínas de Saccharomyces cerevisiae , Ubiquitina , Ubiquitina/genética , Ubiquitina/metabolismo , Saccharomyces cerevisiae/metabolismo , Ligases/genética , Mutação Puntual , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Mutação/genética
6.
Nanotechnology ; 34(7)2022 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-36384032

RESUMO

Manipulating light at the sub-wavelength level is a crucial feature of surface plasmon resonance (SPR) properties for a wide range of nanostructures. Noble metals like Au and Ag are most commonly used as SPR materials. Significant attention is being devoted to identify and develop non-noble metal plasmonic materials whose optical properties can be reconfigured for plasmonic response by structural phase changes. Chromium (Cr) which supports plasmon resonance, is a transition metal with shiny finished, highly non-corrosive, and bio-compatible alloys, making it an alternative plasmonic material. We have synthesized Cr micro-rods from a bi-layer of Cr/Au thin films, which evolves from face centered cubic to hexagonal close packed (HCP) phase by thermal activation in a forming gas ambient. We employed optical absorption spectroscopy and cathodoluminescence (CL) imaging spectroscopy to observe the plasmonic modes from the Cr micro-rod. The origin of three emission bands that spread over the UV-Vis-IR energy range is established theoretically by considering the critical points of the second-order derivative of the macroscopic dielectric function obtained from density functional theory (DFT) matches with interband/intraband transition of electrons observed in density of states versus energy graph. The experimentally observed CL emission peaks closely match thes-dandd-dband transition obtained from DFT calculations. Our findings on plasmonic modes in Cr(HCP) phase can expand the range of plasmonic material beyond noble metal with tunable plasmonic emissions for plasmonic-based optical technology.

7.
Mol Neurobiol ; 59(9): 5379-5407, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35699874

RESUMO

Synuclein aggregation in neuronal cells is the primary underlying cause of synucleinopathies. Changes in gene expression patterns, structural modifications, and altered interactions with other cellular proteins often trigger aggregation of α-synuclein, which accumulates as oligomers or fibrils in Lewy bodies. Although fibrillar forms of α-synuclein are primarily considered pathological, recent studies have revealed that even the intermediate states of aggregates are neurotoxic, complicating the development of therapeutic interventions. Autophagy and ubiquitin-proteasome pathways play a significant role in maintaining the soluble levels of α-synuclein inside cells; however, the heterogeneous nature of the aggregates presents a significant bottleneck to its degradation by these cellular pathways. With studies focused on identifying the proteins that modulate synuclein aggregation and clearance, detailed mechanistic insights are emerging about the individual and synergistic effects of these degradation pathways in regulating soluble α-synuclein levels. In this article, we discuss the impact of α-synuclein aggregation on autophagy-lysosome and ubiquitin-proteasome pathways and the therapeutic strategies that target various aspects of synuclein aggregation or degradation via these pathways. Additionally, we also highlight the natural and synthetic compounds that have shown promise in alleviating the cellular damage caused due to synuclein aggregation.


Assuntos
Doença de Parkinson , alfa-Sinucleína , Autofagia , Humanos , Lisossomos/metabolismo , Doença de Parkinson/patologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Ubiquitina , alfa-Sinucleína/metabolismo
8.
Mol Biol Rep ; 47(12): 9757-9763, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33219479

RESUMO

Kashmir musk deer, Moschus cupreus (KMD) is one the most threatened species endemic to the Himalayan region of Kashmir, Pakistan and Afghanistan. Herein, we have sequenced, annotated and characterized the complete mitogenome of M. cupreus. The investigation and comparison of the mitogenome provide crucial information for phylogenetic analysis to understand the evolutionary relationships. The mitogenome of KMD was 16,354 bp long, comprising 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), two ribosomal RNA genes (rRNAs) and non-coding control region. Its composition was highly A+T biased 68.42%, and exhibited a positive AT-skew (0.082) and negative GC-skew (- 0.307). The phylogenetic analysis suggested that KMD was a primitive and extant species in the genus Moschus, whereas Alpine musk deer (M. chrysogaster) and Himalayan musk deer (M. leucogaster) were the closest relatives. It indicated the placement of M. cupreus within the monotypic family Moschidae of musk deer. Hence, it provides a better understanding of lineage identification and musk deer evolution for further research.


Assuntos
DNA Mitocondrial , Cervos , Genoma Mitocondrial , Filogenia , Afeganistão , Animais , Cervos/classificação , Cervos/genética , Espécies em Perigo de Extinção , Paquistão
9.
Environ Monit Assess ; 189(4): 153, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28281131

RESUMO

A comprehensive analysis on spatiotemporal variation in physico-chemical variables and their control on chlorophyll-a during 2013-14 was carried out in the Chilika Lagoon. Spatiotemporal variation in physico-chemical regimes significantly controlled the phytoplankton biomass of the lagoon. Further, precipitation-induced river/terrestrial freshwater influx and marine influence controlled the physico-chemical regimes of the Chilika Lagoon, such as nutrients (NH4+, NO3-, NO2-, PO43- and Si(OH)4), temperature, salinity, total suspended matter and dissolved oxygen. This study revealed significant effects of tropical cyclones Phailin (2013) and Hudhud (2014) on physico-chemical regimes and in turn the phytoplankton biomass of the lagoon. Although both cyclones Phailin (2013) and Hudhud (2014) were intense, Phailin (2013) had a greater impact on the Chilika Lagoon due to the proximity of its landfall. Heavy precipitation caused an influx of nutrient-rich freshwater, both during each cyclone's passage, through rainfall, and after, through increased river flow and terrestrial run-off. The increase in nutrients, carried by the run-off, promoted phytoplankton growth, albeit in lag phase. In general, phytoplankton growth was controlled by nitrogenous nutrients. However, the addition of SiO4 through terrigenous run-off fuelled preferential growth of diatoms. The salinity pattern (which can be considered a proxy for fresh and marine water influx) indicated injection of freshwater nutrients into the northern, southern and central sectors of the lagoon through riverine/terrestrial freshwater run-off; marine influx was restricted to the mouth of the lagoon. Present and past magnitudes of salinity and chlorophyll-a were also compared to better understand the pattern of variability. A significant change in salinity pattern was noticed after the opening of an artificial inlet, because of the resulting higher influx of marine water. The overall phytoplankton biomass (using chlorophyll-a concentration as a proxy) remained consistent in the lagoon pre- and post-restoration. Due to the wide range of salinity and temperature tolerance, diatoms remained dominant in both pre- and post-restoration periods, but the overall phytoplankton diversity increased after the artificial inlet was dredged.


Assuntos
Clorofila/análise , Tempestades Ciclônicas , Monitoramento Ambiental , Água do Mar/química , Baías , Biomassa , Clorofila A , Diatomáceas , Monitoramento Ambiental/métodos , Água Doce/análise , Índia , Nitrogênio/análise , Fitoplâncton/crescimento & desenvolvimento , Rios , Salinidade , Estações do Ano , Temperatura
10.
Bull Environ Contam Toxicol ; 98(3): 439-445, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27704186

RESUMO

Pretilachlor treatments, namely, recommended dose at 600 g a.i. ha-1 (RD), double the recommended dose at 1200 g a.i. ha-1 (2RD), ten times of the recommended dose at 6000 g a.i. ha-1 (10RD) along with control, were used to study the effects of pretilachlor on soil enzymes in tropical rice soil. Pretilachlor, at recommended dose completely dissipated 30 days after herbicide application. Twenty days after herbicide application, the dehydrogenase activity was inhibited up to 27 %, 28 % and 40 % of initial values of RD, 2RD and 10RD treatments, respectively. Increase in fluorescein diacetate hydrolase activity was observed during the first 25 days post herbicide application up to 29 %, 36 % and 10 % of initial values of RD, 2RD and 10RD treatments, respectively. ß-Glucosidase activity in the experiment did not provide a specific trend. In general, urease and acid phosphatase activities were not influenced by pretilachlor application. There were significant differences in alkaline phosphatase activities among the treatments until 25 days after herbicide application. Hence, pretilachlor may cause short term transitory changes in soil enzyme parameters. However, it has negative impact on soil enzymes at very high dose.


Assuntos
Acetanilidas/toxicidade , Enzimas/efeitos dos fármacos , Solo/química , Acetanilidas/análise , Relação Dose-Resposta a Droga , Enzimas/metabolismo , Microbiologia do Solo , Fatores de Tempo
11.
Mar Pollut Bull ; 111(1-2): 277-286, 2016 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-27449626

RESUMO

An intense bloom of red Noctiluca scintillans (NS) occurred off the Rushikulya estuarine region along the east coast of India, an important site for mass nesting events of the vulnerable Olive Ridley sea turtle. At its peak, densities of NS were 3.3×10(5) cells-l(-1), with low relative abundance of other phytoplankton. The peak bloom coincided with high abundance of gelatinous planktivores which may have facilitated bloom development by their grazing on other zooplankton, particularly copepods. Ammonium concentrations increased by approximately 4-fold in the later stages of bloom, coincident with stable NS abundance and chlorophyll concentrations in the nano- and microplankton. This increase likely was attributable to release of intracellular ammonium accumulated through NS grazing. Dissolved oxygen concentrations decreased in sub-surface waters to near hypoxia. Micro-phytoplankton increasingly dominated chlorophyll-a biomass as the bloom declined, with diminishing picoplankton abundance likely the result of high predation by the ciliate Mesodinium rubrum. Together, these data illustrate factors that can disrupt ecosystem balance in this critically important Indian coastal region.


Assuntos
Dinoflagellida/crescimento & desenvolvimento , Eutrofização , Cadeia Alimentar , Amônia/análise , Amônia/metabolismo , Animais , Biomassa , Clorofila/metabolismo , Clorofila A , Cilióforos/fisiologia , Copépodes , Ecossistema , Monitoramento Ambiental/métodos , Índia , Fitoplâncton/crescimento & desenvolvimento , Dinâmica Populacional , Cifozoários/fisiologia , Clima Tropical , Zooplâncton
12.
Environ Sci Pollut Res Int ; 23(8): 7595-602, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26739987

RESUMO

The use of herbicides has been questioned in recent past for their non-target effects. Therefore, we planned to study the effect of pretilachlor on growth and activities of microbes in tropical rice soil under controlled condition at National Rice Research Institute, Cuttack, India. Three pretilachlor treatments, namely, recommended dose at 600 g a.i. ha(-1) (RD), double the recommended dose at 1200 g a.i. ha(-1) (2RD), and ten times of the recommended dose at 6000 g a.i. ha(-1) (10RD) along with control, were imposed. The initial residue (after 2 h of spray) deposits in soil were 0.174, 0.968, and 3.35 µg g(-1) for recommended, double the recommended, and ten times of the recommended doses, respectively. No residue in soil was detected in RD treatment on day 45. The half life values were 16.90, 17.76, and 36.47 days for RD, 2RD, and 10RD treatments, respectively. Application of pretilachlor at 10RD, in general, had significantly reduced the number of bacteria, actinomycetes, fungi, nitrogen fixers, and microbial biomass carbon. Pretilachlor at RD did not record any significant changes in microbial properties compared to control. The results of the present study thus indicated that pretilachlor at RD can be safely used for controlling grassy weeds in rice fields.


Assuntos
Acetanilidas/toxicidade , Consórcios Microbianos/efeitos dos fármacos , Oryza/crescimento & desenvolvimento , Microbiologia do Solo , Poluentes do Solo/toxicidade , Solo/química , Actinomyces/efeitos dos fármacos , Actinomyces/crescimento & desenvolvimento , Biomassa , Carbono/análise , Fungos/efeitos dos fármacos , Fungos/crescimento & desenvolvimento , Índia , Fixação de Nitrogênio/efeitos dos fármacos
13.
J Pharm Anal ; 6(5): 341-344, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29404002

RESUMO

This article introduced the work of ethylcellulose based polymeric microsphere loaded with nifedipine for reduction in frequency of administration with low solubility in aqueous medium and high rate of absorption in the stomach. The non-aqueous polymeric suspension was put dropwise into an aqueous medium containing polyvinyl alcohol as a surfactant for the synthesis of microsphere by solvent evaporation. The microspheres were characterized by different techniques, namely, XRD, SEM, and NMR. The formation of microspheres was confirmed by SEM. XRD analysis revealed the semi-crystallinity nature of microspheres. The NMR study indicated the presence of hetero-aromatic nucleus in the microsphere.

14.
Saudi Pharm J ; 23(2): 195-201, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25972741

RESUMO

Considering the importance of drug permeation from formulations, in vitro and ex vivo drug permeation characteristics of three oral mucoadhesive suspensions of Ofloxacin were designed and compared. Three suspensions of Ofloxacin were prepared by taking two grades of Carbopol polymer such as Carbopol 934 (C934) and Carbopol 940 (C940); and Hydroxypropyl methylcellulose. The permeability study was performed by using a Franz diffusion cell through both synthetic cellulose acetate membrane and excised goat gastrointestinal membranes in acidic as well as alkaline pH. To know the permeability of the drug from control/formulations through different membranes in acidic/alkaline pH, cumulative percentage drug permeation, apparent permeability (Papp) and flux (J) were calculated. In addition, enhancement ratio (ER) of each formulation was also determined. From our results, it is evident that formulation containing C940 was the best suspension considering Papp and J values of all formulations. Moreover, it was the most beneficial formulation for improving permeation and diffusivity of Ofloxacin even after 16 h. Hence, this suspension was probably the most suitable formulation to obtain prolonged release action of the drug. The ER values of all formulations through the excised goat intestinal mucus membrane in alkaline pH were higher than those formulations through the goat stomach mucosal membrane in acidic pH. ER values of those formulations indicate that the permeability of the drug was more enhanced by the polymers in the intestinal part, leading to more bioavailability and prolonged action in that portion of the gastrointestinal tract. It may also be concluded from our results that in addition to formulation containing C940, other formulations may also show effective controlled release action.

15.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-672958

RESUMO

This article introduced the work of ethylcellulose based polymeric microsphere loaded with nifedipine for reduction in frequency of administration with low solubility in aqueous medium and high rate of absorption in the stomach. The non-aqueous polymeric suspension was put dropwise into an aqueous medium containing polyvinyl alcohol as a surfactant for the synthesis of microsphere by solvent eva-poration. The microspheres were characterized by different techniques, namely, XRD, SEM, and NMR. The formation of microspheres was confirmed by SEM. XRD analysis revealed the semi-crystallinity nature of microspheres. The NMR study indicated the presence of hetero-aromatic nucleus in the microsphere.

16.
J Adv Pharm Technol Res ; 5(3): 140-6, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25126536

RESUMO

Since permeability across biological membranes is a key factor in the absorption and distribution of drugs, drug permeation characteristics of three oral suspensions of ciprofloxacin were designed and compared. The three suspensions of ciprofloxacin were prepared by taking biodegradable polymers such as carbopol 934, carbopol 940, and hydroxypropyl methylcellulose (HPMC). The permeability study was performed by using a Franz diffusion cell through both synthetic cellulose acetate membrane and excised goat gastrointestinal membranes in acidic as well as alkaline pH. To know the permeability of drug from control/formulations through different membranes in acidic/alkaline pH, cumulative percentage drug permeation, apparent permeability (Papp), flux, and enhancement ratio (ER) were calculated. Considering Papp and flux values of all formulations, it is evident that formulation containing HPMC was the most beneficial for improving permeation and diffusivity of ciprofloxacin even after 16 h. Hence, this preparation may be considered as the most suitable formulation to obtain prolonged release action of the drug. The ER values of all formulations, through excised goat intestinal mucosal membrane in alkaline pH, were higher than those formulations through goat stomach mucosal membrane in acidic pH. Enhancement ratio values of those formulations indicate that the permeability of the drug was more enhanced by the polymers in the intestinal part, leading to more bioavailability and prolonged action in that portion of the gastrointestinal tract. It may also be concluded from our results that HPMC containing formulation was the best suspension, which may show effective controlled release action. Even carbopol containing formulations might also produce controlled release action.

17.
Appl Radiat Isot ; 89: 192-8, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24681624

RESUMO

Preparation of three mucoadhesive formulations was optimized and pharmaceutically evaluated. Ofloxacin was radiolabeled with (99m)Tc and radiolabeled complex was characterized by HPLC. (99m)Tc-Ofloxacin was added as a tracer to the formulations namely Oflox C934, Oflox C940 and Oflox HPMC and the formulations were fed orally to rats. Imaging studies were carried out to assess the prolonged gastric retention of the formulations. (99m)Tc-Ofloxacin served as a good tracer for studying the pharmacokinetics of three controlled release mucoadhesive dosage forms by gamma scintigraphy studies.


Assuntos
Ofloxacino/administração & dosagem , Ofloxacino/síntese química , Compostos de Organotecnécio/administração & dosagem , Compostos de Organotecnécio/síntese química , Compostos Radiofarmacêuticos/administração & dosagem , Compostos Radiofarmacêuticos/síntese química , Acrilatos/química , Resinas Acrílicas/química , Animais , Preparações de Ação Retardada , Derivados da Hipromelose/química , Marcação por Isótopo/métodos , Microscopia Eletrônica de Varredura , Ofloxacino/química , Ofloxacino/farmacocinética , Compostos de Organotecnécio/química , Compostos de Organotecnécio/farmacocinética , Cintilografia , Compostos Radiofarmacêuticos/química , Compostos Radiofarmacêuticos/farmacocinética , Ratos , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
18.
J Adv Pharm Technol Res ; 2(3): 195-204, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22171318

RESUMO

Mucoadhesive polymeric (carbopol 934) suspension of ciprofloxacin was prepared by ultrasonication and optimized with the aim of developing an oral controlled release gastro-retentive dosage form. The qualitative analysis of the formulation was performed by fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray powder diffraction (XRD), and scanning electron microscopy (SEM) analyses. FTIR (400 cm(-1) to 4000 cm(-1) region) and Raman (140 to 2400 cm(-1) region) Spectroscopic studies were carried out and the spectra were used for interpretation. XRD data of pure drug, polymer and the formulation were obtained using a powder diffractometer scanned from a Bragg's angle (2θ) of 10° to 70°. The dispersion of the particle was observed using SEM techniques. The particle size distribution and aspect ratio of particles in the polymeric suspension were obtained from SEM image analysis. The results from FTIR and Raman spectroscopic analyses suggested that, in formulation, the carboxylic groups of ciprofloxacin and hydroxyl groups of C934 undergo a chemical interaction leading to esterification and hydrogen bonding. The XRD data suggested that the retention of crystalline nature of ciprofloxacin in the formulation would lead to increase in stability and drug loading; decrease in solubility; and delay in release of the drug from polymeric suspension with better bioavailability and penetration capacity. The SEM image analysis indicated that, in the formulation maximum particles were having aspect ratio from 2 to 4 and standard deviation was very less which provided supporting evidences for homogeneous, uniformly dispersed, stable controlled release ciprofloxacin suspension which would be pharmaceutically acceptable.

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