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1.
Int J Biol Macromol ; 253(Pt 5): 127173, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37783253

RESUMO

The present study aimed to evaluate Cassia fistula seed galactomannan (CFSG) as a tablet-binder in the formulation of a monolithic matrix tablet using diclofenac sodium as a model drug. Initially, CFSG was extracted and purified from the seeds of the Cassia fistula tree and then screened for phytochemicals. Native CFSG was characterized with polysaccharide content determination, monosaccharide composition analysis, elemental analysis, FTIR, solid-state 13C NMR, molecular weight, zeta potential, DSC, TGA-DTA, XRD, viscosity, pH and surface tension, rheology, SEM and acute oral toxicity study. Prior to formulation, the drug-CFSG compatibility was checked by FTIR, DSC, and XRD. Diclofenac sodium-loaded granules were prepared by the wet granulation method and evaluated for various granule properties. Finally, granules were compressed into tablets and evaluated for binding and other tablet properties. The granules showed to have optimum micromeritic properties. Tablet hardness and friability were found to be approximately 7 kg/m2 and 0.3 %, respectively, which substantiate the excellent binding capacity of CFSG. Other tablet properties were also found to be within the Pharmacopoeial compliance limit. The tablets with a minimum concentration of CFSG (2.5%w/w) as binder showed appreciable mechanical strength and faster drug release, which ratifies CFSG as an alternative tablet binder.


Assuntos
Cassia , Diclofenaco , Sementes , Comprimidos/química , Solubilidade
2.
Int J Biol Macromol ; 163: 842-853, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32653379

RESUMO

The main objective of the present study was to develop a sustained release multiple-unit beads of lamotrigine based on ionotropically cross-linked natural polysaccharides such as pectin (PTN) and okra mucilage (OM) and optimize the polymer-concentration, polymer ratio and cross-linker concentration by 23 full factorial design. Two different levels of three independent variables (total polymer concentration, polymer ratio and [CaCl2]) were considered for the experimental design. Drug-polymers compatibility was examined by FTIR, DSC, TGA and powder-XRD. The surface morphology of the bead before and after dissolution test was examined by SEM. Effects of the independent variables on bead-size, drug-encapsulation-efficiency (DEE), drug-release along with release similarity and difference factors were examined. The independent variables were then numerically optimized using Design-Expert software (Version 12) with the targets to meet USP-reference release profile after the analysis of variance of all the response parameters such as DEE, percent drug release at 2 h, 5 h, 12 h, Korsmeyer-Peppas rate constant, release similarity and difference factors. The optimized formulation showed excellent DEE of 89.2 ± 4.4% and a sustained release profile with release similarity factor of 94.9. Kinetic modeling of drug release data demonstrated a release mechanism combined of hydration, diffusion and erosion.


Assuntos
Abelmoschus/química , Portadores de Fármacos/química , Lamotrigina/administração & dosagem , Microesferas , Pectinas/química , Mucilagem Vegetal/química , Bloqueadores dos Canais de Sódio/administração & dosagem , Varredura Diferencial de Calorimetria , Preparações de Ação Retardada , Composição de Medicamentos , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Estabilidade de Medicamentos , Concentração de Íons de Hidrogênio , Tamanho da Partícula , Mucilagem Vegetal/isolamento & purificação , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria , Difração de Raios X
3.
Carbohydr Polym ; 215: 213-225, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30981348

RESUMO

In the present study, polyacrylamide-grafted-tamarind seed gum (PAAm-g-TSG) was synthesised employing free radical method assisted with microwave where cerric (IV) ammonium nitrate (CAN) was used as free radical initiator. Effects of monomer, CAN and microwave irradiation time (MW) on grafting were studied. Various grafting indicators such as % grafting (%G), % grafting efficiency (%GE) and % conversion (%Cn) were calculated. MW and CAN exhibited major contribution in the synthesis. Highest % grafting (890.3%) was shown in the batch with 10 g acrylamide, 400 mg CAN and 1 min MW. Grafted TSG was then characterized by elemental analysis, FTIR, solid state 13C NMR, DSC, TGA, XRD, viscosity, SEM, acute oral toxicity and biodegradability study. Nontoxic and biodegradable natures of PAAm-g-TSG were revealed in the study. Finally, flocculating property of the grafted gum was evaluated in paracetamol suspension. The flocculation study demonstrates that all batches of graft copolymer showed to have good flocculating efficiency in paracetamol suspension and the capacity increases with increase in both concentration and grafting. S11 batch (highest %G = 890.3) exhibited highest degree of flocculation (ß = 5.14 ± 0.26) among others.

4.
Int J Biol Macromol ; 96: 137-148, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27956100

RESUMO

Development of a gastroretentive sustained release tablet of metformin based on poly (acrylic acid)-grafted-gellan (PAAc-g-GG) is the main purpose of this study. At first, PAAc-g-GG was synthesized by microwave-promoted free radical initiation method using cerric (IV) ammonium nitrate (CAN) as redox initiator and characterized by elemental analysis, FTIR, DSC-TGA, 13C NMR, biodegradation and viscosity study. The synthetic parameters were optimized by 23 full factorial design using Design Expert software. Acute oral toxicity and histological studies were also performed as per OECD guideline. Tablets were then prepared employing wet granulation method using PAAc-g-GG and evaluated for various physical characters, in vitro drug release, ex-vivo mucoadhesion and swelling. Compatibility between drug and excipients was checked by DSC and FTIR analysis. The F3 batch showed excellent mucoadhesion and sustained drug release over a period of 10h with dissolution similarity factor, f2=77.43. Kinetic modeling unveiled Case-1 Fickian diffusion based drug release mechanism.


Assuntos
Resinas Acrílicas/química , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Mucosa Gástrica/metabolismo , Metformina/química , Metformina/metabolismo , Polissacarídeos Bacterianos/química , Adesividade , Animais , Preparações de Ação Retardada , Feminino , Mucosa Gástrica/química , Camundongos , Micro-Ondas , Comprimidos , Viscosidade
5.
Carbohydr Polym ; 137: 100-110, 2016 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-26686110

RESUMO

Formulation of a gastroretentive extended release tablet of metformin based on polymethacrylamide-g-gellan (Pmaa-g-GG)-tamarind seed gum (TSG) composite matrix is the main purpose of this study. Tablets were prepared employing wet granulation method taking amount of Pmaa-g-GG, TSG and NaHCO3 (SBC, buoyancy contributor) as independent formulation variables. The tablets were then evaluated for in vitro drug release, buoyancy, ex vivo mucoadhesion, swelling and surface morphology. Compatibility between drug and excipients was checked by DSC, FTIR and XRD analysis. Buoyancy-lag-time, mucoadhesive strength, % drug release and release-rate constant were statistically analyzed using Design-Expert software (version 9.0.4.1) and the formulation was then numerically optimized to obtain USP-reference release profile. The optimized formulation showed excellent buoyancy over a 10h period with buoyancy lag time of 2.76min, significant mucoadhesion and drug release over a period of 10h with f2=71.58. Kinetic modeling unveiled anomalous non-Fickian transport based drug release mechanism.


Assuntos
Acrilamidas/química , Preparações de Ação Retardada/química , Metformina/química , Polissacarídeos Bacterianos/química , Sementes/química , Tamarindus/química , Animais , Liberação Controlada de Fármacos , Excipientes/química , Cabras
6.
Int J Biol Macromol ; 72: 965-74, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25316428

RESUMO

In the present study, the microwave induced synthesis of polymethacrylamide-grafted-gellan gum (PMaa-g-GG) was carried out by free radical initiation using cerric (IV) ammonium nitrate (CAN) as redox initiator. Concentrations of methacrylamide (Maa), CAN and microwave irradiation time were taken as variable synthetic parameters. The modified polysaccharide obtained from different synthetic conditions was then characterized by FTIR, CHN analysis, DSC and powder X-ray diffraction. The yield and extent of grafting were assessed by determining percentage grafting, percentage grafting efficiency, percentage conversion and these were correlated with elemental analysis. The acute oral toxicity study of modified polysaccharide was performed as per OECD guideline. Histological comparison of different organs between control and test animal showed no significant difference. Sustained release tablets of diclofenac sodium (DS) were prepared with modified gellan. In vitro dissolution study showed the tablets were capable of releasing the drug over a period of 8 h.


Assuntos
Acrilamidas/administração & dosagem , Preparações de Ação Retardada , Polissacarídeos Bacterianos/administração & dosagem , Comprimidos/administração & dosagem , Acrilamidas/síntese química , Acrilamidas/química , Animais , Diclofenaco/química , Humanos , Camundongos , Micro-Ondas , Gomas Vegetais/química , Ácidos Polimetacrílicos/síntese química , Ácidos Polimetacrílicos/química , Polissacarídeos Bacterianos/síntese química , Polissacarídeos Bacterianos/química , Espectroscopia de Infravermelho com Transformada de Fourier , Comprimidos/síntese química , Comprimidos/química , Difração de Raios X
7.
Pharm Dev Technol ; 16(4): 385-91, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20429816

RESUMO

The poor bioavailability and therapeutic response exhibited by conventional ophthalmic solutions may be overcome by the use of thermo-reversible in situ gel. The purpose of this study was to examine the influence of different salts on the gelation, rheology and drug release of in situ gel based on methylcellulose. The gel temperature of 1% w/v methylcellulose (MC) was 60?C. It was found that 5?7% w/v sodium chloride (NaCl), 8?9% w/v potassium chloride (KCl), or 5% w/v sodium bicarbonate (NaHCO(3)) was capable of decreasing the gel temperature below physiological temperature, i.e. 37?C. Rheological studies indicated a large increase in viscosity at 37?C with the addition of salts in MC solutions. The duration of drug release from MC solution was 1.5?h. The significant observation was that the duration of drug release increased from 1.5?h to 3?5?h from salted MC solutions depending on the concentration and the type of salt. So, it can be concluded that the salted MC solutions were a better alternative than the MC solution to enhance the ocular bioavailability of the drug.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Géis/química , Cetorolaco de Trometamina/administração & dosagem , Soluções Oftálmicas/administração & dosagem , Administração Tópica , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/farmacocinética , Química Farmacêutica , Preparações de Ação Retardada/química , Estabilidade de Medicamentos , Géis/administração & dosagem , Cetorolaco de Trometamina/farmacocinética , Metilcelulose/química , Soluções Oftálmicas/química , Soluções Oftálmicas/farmacocinética , Reologia , Lágrimas/metabolismo , Temperatura , Água/química
8.
Braz. j. pharm. sci ; 45(3): 585-591, July-Sept. 2009. ilus, graf, tab
Artigo em Inglês | LILACS | ID: lil-533187

RESUMO

The objectives of our study were to prepare and evaluate a biodegradable nanoparticulate system of Letrozole (LTZ) intended for breast cancer therapy. LTZ loaded poly(lactide-co-glycolide) nanoparticles (LTZ-PLGA-NPs) were prepared by emulsion-solvent evaporation method using methylene chloride and polyvinyl alcohol. Percentage of drug (with respect to polymer) was selected as formulation variable. LTZ-PLGA-NPs were characterized by particle size, zeta potential, infrared spectra, drug entrapment efficiency and in vitro release. Sonication was done with an ultrasound pulse sonicator at 70 W, 30 kHz for 90 sec to produce stable NPs of mean size range from 64 nm to 255 nm with high entrapment efficiency (68 percent to 82 percent). Percentage of drug significantly influenced particle size, entrapment efficiency and release (p <0.05). The system sustained release of LTZ significantly and further investigation could exhibit its potential usefulness in breast cancer therapy.


Os objetivos de nosso estudo foram preparar e avaliar o sistema de nanopartícula biodegradável de letrozol na terapia de câncer mamário. Nanopartículas de poli(lactídeo-co-glicolídeo) carregadas com LTZ (LTZ-PLGA-NPs) foram preparadas pelo método de emulsão-evaporação de solvente, utilizando dicloro metano e álcool polivinílico. A porcentagem do fármaco (com relação ao polímero) foi selecionada como variável da formulação. LTZ-PLGA-NPs foram caracterizadas pelo tamanho da partícula, potencial zeta, espectros no infravermelho, eficiência de inclusão e liberação in vitro. A sonicação foi realizada com sonicador de ultrassom, de pulso a 70W e 30 kHz por 90 segundos para produzir NPs estáveis, de faixa de tamanho médio de 64 nm a 266 nm, com alta eficiência de inclusão (68 por cento a 82 por cento). A porcentagem do fármaco foi significativamente influenciada pelo tamanho da partícula, eficiência de inclusão e liberação (p<0,05). O sistema controlou significativamente a liberação de LTZ e estudos posteriores poderiam mostrar sua utilidade potencial na terapia de câncer de mama.


Assuntos
Inibidores da Aromatase , Neoplasias da Mama , Avaliação de Medicamentos , Desenvolvimento Experimental , Nanopartículas , Terapêutica/métodos , Sinergismo Farmacológico , Escalas de Preparação , Química Farmacêutica/métodos
9.
J Indian Med Assoc ; 100(12): 706-7, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12793635

RESUMO

Forensic medicine, the subject in undergraduate medical curriculum is becoming more and more important for undergraduate students. Forensic psychiatry is being very much felt an important part of crime and criminology and is being thoroughly neglected. We cannot ignore the mental status of a person in relation to commission of a crime as it is the case in all spheres of life. So updating forensic psychiatry in educational programme may play key roles in crime investigations. The law can judge the merit of a case on the basis of how far the mental abnormality might influence to commit a crime. Investigation of crime has to be a compulsorily team work consisting of man of forensic psychiatry or at least forensic medicine expert and the other investigating agencies.


Assuntos
Psiquiatria Legal/normas , Pessoas Mentalmente Doentes , Papel do Médico , Violência , Pena de Morte , Criminologia , Prova Pericial , Humanos , Índia
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