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1.
Indian J Endocrinol Metab ; 27(3): 255-259, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37583407

RESUMO

Context: Osteogenesis imperfecta (OI) is a genetic disorder of the extracellular matrix of bone characterized by low bone mass manifesting as frequent fractures, delayed motor development, pain, and impaired quality of life. The intravenous bisphosphonate, pamidronate is an established treatment for OI. Recently, zoledronic acid (ZA) has been used for the management of OI. Aim: To assess the efficacy and safety of ZA in children below five years of age with OI. Settings and Design: A hospital-based prospective observational study. Methods and Material: Patients with OI aged less than five years attending our centre were treated with intravenous ZA at a dose of 0.05 mg/kg every six months. Subjects were closely monitored for clinical and biochemical variables, adverse events, and new-onset fractures. The response to therapy was assessed by monitoring clinical variables including the degree of bony pains, number of fractures, height/length standard deviation score (SDS), and motor developmental milestones. All patients were analysed at baseline and at the end of two years for biochemical parameters and clinical severity score (CSS) as proposed by Aglan et al. with modifications. Results: After two years of treatment, OI patients showed a significant decline in the rate of fractures (p < 0.001), improvement in ambulation (p = 0.005), alleviation of pain (p < 0.001), and improvement in height SDS (p < 0.05). There was a significant improvement in CSS after two years of therapy. Apart from mild flu-like symptoms and mild asymptomatic hypocalcaemia immediately post-infusion, no other adverse effect was noted. Conclusion: ZA therapy in infants and children below five years of age with OI was effective and safe and a more convenient alternative to pamidronate.

2.
Bioorg Med Chem Lett ; 67: 128747, 2022 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-35476959

RESUMO

For developing novel therapeutic agents with good anticancer activities, a series of novel pyridine-pyrimidine hybrid phosphonate derivatives4(a-q) were synthesized by the Kabachnik-Fields method using CAN as catalyst. The compound 4o exhibited the most potent anticancer activity with an IC50 value of 13.62 µM, 17.49 µM, 5.81 µM, 1.59 µM and 2.11 µM against selected cancer cell lines A549, Hep-G2, HeLa, MCF-7, and HL-60, respectively. Compound 4o displayed seven times more selectivity towards Hep-G2 cancer cell lines compared to the human normal hepatocyte cell line LO2 (IC50 value 95.33 µM). Structure-Activity Relationship (SAR) studies were conducted on the variation in the aromatic ring (five-membered heterocyclic ring, six-membered heterocyclic ring) and the variation of substituents on the phenyl ring (electron donating groups, electron withdrawing groups). Furthermore, the mechanism of anticancer activity was clarified by further explorations in bioactivity by using in vitro aurora kinase inhibitory activity and molecular docking studies. The results showed that the compound 4o at IC50concentrationdemonstrated distinctive morphological changes such as cell detachment, cell wall deformation, cell shrinkage and reduced number of viable cells in cancer cell lines. Compound 4o induced early apoptosis and late apoptosis of 27.7% and 6.1% respectively.


Assuntos
Antineoplásicos , Organofosfonatos , Antineoplásicos/farmacologia , Aurora Quinases , Linhagem Celular Tumoral , Proliferação de Células , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Simulação de Acoplamento Molecular , Estrutura Molecular , Organofosfonatos/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Piridinas/farmacologia , Pirimidinas/farmacologia , Relação Estrutura-Atividade
3.
Indian J Dent Res ; 29(6): 794-798, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30589010

RESUMO

CONTEXT: Long-term retention of the restoration depends on strength and durability of the bond of the luting composite resin to the tooth and the porcelain substrates. AIMS: This in vitro study was conducted to compare and evaluate the influence of hydrofluoric acid (HF) and acidulate phosphate fluoride (APF) gel-etched treatments on surface roughness and bond strength to dentin of a commercially available lithium disilicate ceramic (E-Max). SUBJECTS AND METHODS: Sixty lithium disilicate ceramic disks measuring 5 mm in diameter and 2 mm thick were fabricated and divided into three groups: Group A (n = 24), Group B (n = 24), and Group C (n = 12) and were subdivided to Group A1, A2, and A3which were surface treated with 1.23% APF gel (pH = 3-4) at different time intervals 4, 7, and 10 min, respectively. Group B1, B2, and B3 were surface treated with 1% APF gel (pH = 1-2) at different time intervals 4, 7, and 10 min, respectively. Group C were surface treated with 9.6% HF (pH = 1-2) for 1 min. Morphological changes obtained with the surface treatments were analyzed using a surface profilometer. STATISTICAL ANALYSIS: All specimens were subjected to a tensile bond strength test using a tensometer, and the obtained data were statistically analyzed using Kruskal-Wallis test. RESULTS: The surface roughness (µm) and bond strength (MPa) of lithium disilicate discs (samples) etched with 1.23% APF gel and 1% APF gel for 10 min and etched with 9.6% HF for 1 min showed no statistical significant difference among them. CONCLUSIONS: In this study, the lithium disilicate discs etched with 1.23% APF gel and 1% APF gel for 10 min showed similar surface roughness and bond strength to those etched with 9.6% HF for a minute.


Assuntos
Fluoreto de Fosfato Acidulado , Cerâmica , Resinas Compostas , Porcelana Dentária , Dentina , Ácido Fluorídrico , Resistência à Tração , Géis , Humanos , Técnicas In Vitro , Propriedades de Superfície
4.
Natl Med J India ; 30(2): 93-96, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28816219

RESUMO

BACKGROUND: Equity in health and equitable access to healthcare has been at the core of health policy in India. The key policy challenge has been how to make that possible? Various health insurance schemes such as the Rashtriya Swasthya Bima Yojana and Arogyasri seek to improve poor people's access to specialist medical care in the public and private sectors. On the other hand, access to primary medical care has been left to the supply side interventions. METHODS: We did a focused review of evidence on equity aspects of primary medical care versus specialist medical care. We selected relevant publications from the Cochrane Library, PubMed and Google Scholar searches and articles snowballing out of them. RESULTS: Higher primary care physician-to-population ratio is invariably associated with better health outcomes. Primary care may partly protect the poor from adverse effects of income inequality on health status. On the other hand, populations do not necessarily benefit from an overabundance of specialists in a geographical area. CONCLUSIONS: Three key policy lessons emerge from this review. First, states should strengthen primary medical care by upgrading health centres. Second, a family health protection plan should be introduced as a demand side intervention to deliver primary care through health centres, non-profit and for-profit clinics. Third, postgraduate courses in family medicine should be introduced for a balanced development of the specialty of primary care pari passu other specialties.


Assuntos
Assistência Integral à Saúde/métodos , Política de Saúde , Seguro Saúde , Médicos de Atenção Primária/economia , Especialização/economia , Assistência Integral à Saúde/economia , Disparidades em Assistência à Saúde/economia , Disparidades em Assistência à Saúde/legislação & jurisprudência , Índia , Avaliação de Processos e Resultados em Cuidados de Saúde
5.
s.l; The National medical journal of India; 2017. 4 p.
Monografia em Inglês | PIE | ID: biblio-1008324

RESUMO

Equity in health and equitable access to healthcare has been at the core of health policy in India. The key policy challenge has been how to make that possible? Various health insurance schemes such as the Rashtriya Swasthya Bima Yojana and Arogyasri seek to improve poor people's access to specialist medical care in the public and private sectors. On the other hand, access to primary medical care has been left to the supply side interventions.


Assuntos
Humanos , Assistência Integral à Saúde/economia , Assistência Integral à Saúde/métodos , Disparidades em Assistência à Saúde/economia , Políticas, Planejamento e Administração em Saúde/economia , Índia
6.
Integr Med Res ; 5(4): 244-249, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28462125

RESUMO

Heart disease comprises a wide class of cardiovascular abnormalities, including ischemic heart disease, myocardial infarction, atherosclerosis, and coronary artery disease. It is the leading cause of death all over the world. Several traditional and novel risk factors, such as infectious and noninfectious agents, have been associated with heart disease. Out of these, Helicobacter pylori has been recently introduced as an important etiological factor for heart disease. Numerous seroepidemiological findings observed H. pylori antibodies in the blood of a patient with cardiovascular complications. The bacteria survive in the epithelial cells of gastric organs and cause digestive complications. Excess inflammatory pathogenesis and prognosis stimulate an immune response that further causes significant disturbances in various factors like cytokines, fibrinogen, triglycerides, high density lipoprotein, C-reactive protein, heat shock protein, and white blood cell count, and provoke a number of problems such as atherosclerosis and prothrombic state, and cross-reactivity which eventually leads to heart diseases. H. pylori releases toxigenic nutrients, chiefly vacuolating cytotoxin gen A (Vac A) and cytotoxin associated gene A (Cag A), of which Cag A is more virulent and involved in the formation of cholesterol patches in arteries, induction of autoimmune disorder, and release of immune mediated response. Although numerous mechanisms have been correlated with H. pylori and heart disease, the exact role of bacteria is still ambiguous.

7.
Colloids Surf B Biointerfaces ; 108: 366-73, 2013 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-23602990

RESUMO

Fenofibrate (FBT) is lipophillic drug used in hypercholesterolemia and hypertriglyceridemia having logP 5.375, low solubility (practically insoluble in water) and low oral bioavailability (36%). The purpose of work was to develop FBT nanocrystals for the enhancement of solubility and oral bioavailability. Fenofibrate nanosuspension was prepared using probe sonicator and transformed into dry powder using freeze drying and characterized by DSC, FTIR, XRPD, SEM, particle size, polydispersity index (PDI), zeta potential, solubility, in vitro dissolution, in vivo bioavailability and stability studies. Formulation FNS3 and pure drug exhibited the in vitro dissolution about 73.89% and 8.53% in 1% sodium lauryl sulfate (SLS) media, respectively. When the particle size reduced from 80,000±923nm to 460±20nm, saturation solubility was significantly increased. The saturation solubility of formulation FNS3 in 0.5% and 1% of SLS media found to be 67.51±1.5µg/mL and 107±1.9µg/mL, respectively. While, the saturation solubility of pure drug in 0.5% and 1% of SLS was found to be 6.02±1.51µg/ml and 23.54±1.54µg/ml, respectively. The pharmacokinetic study of optimized nanocrystals (FNS3) conducted in New Zealand white rabbits showed 4.73-fold increase in relative bioavailability than that of pure drug. Long term stability studies showed that there was no significant change in the mean particle size and PDI at 5°C±3°C after 180 days. This enhanced dissolution and bioavailability of fenofibrate nanocrystals could be the promising approach for oral delivery.


Assuntos
Fenofibrato/química , Fenofibrato/farmacocinética , Hipolipemiantes/química , Hipolipemiantes/farmacocinética , Nanopartículas/química , Administração Oral , Animais , Área Sob a Curva , Disponibilidade Biológica , Estabilidade de Medicamentos , Feminino , Liofilização , Masculino , Microscopia Eletrônica de Varredura , Nanopartículas/ultraestrutura , Tamanho da Partícula , Pós , Coelhos , Dodecilsulfato de Sódio , Solubilidade , Sonicação , Espectroscopia de Infravermelho com Transformada de Fourier
8.
J Pharm Pharmacol ; 65(1): 79-93, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23215691

RESUMO

OBJECTIVES: In oral absorption of a drug, the drug first dissolves and then is absorbed by diffusion through gastrointestinal membranes. The gastrointestinal environment is aqueous in nature and it is well-known that one-third of the drug population is water insoluble. Hence, there is a need for enhancement of the solubility and dissolution of such drugs. In this work, enhancement of the solubility and dissolution of the practically insoluble drug glipizide was achieved by formation of bionanocomposites (BNCs) using microwave-induced diffusion (MIND), which ultimately leads to bioavailability enhancement. METHODS: BNCs were formed by using natural carriers such as gelatin, acacia, cassia and ghatti gum, with the help of microwaves. Selection of carriers was based on their surfactant and wetting properties. Solubility studies were carried out to establish the solubility-enhancing property of the BNCs. To support solubility analysis results, dissolution studies (i.e. powder dissolution and in-vitro dissolution) were carried out. The BNCs were characterized by Fourier transform infra-red spectroscopy, differential scanning calorimetry, X-ray diffraction studies, scanning electron microscopy and transmission electron microscopy. In-vivo performance of the optimised formulation was assessed by glucose-induced hyperglycaemia test in male albino Wistar rats. KEY FINDINGS: It was found that as the concentration of polymer in the composite increased the solubility and dissolution of glipizide were enhanced. The optimised ratio (drug : polymer) for all the composites was found to be 1:9. In the glucose-induced hyperglycemia test in rats, the optimized formulation demonstrated a significant reduction in hyperglycemia compared with a marketed formulation, Glynase. CONCLUSIONS: The novelty of this work is the green and cost-effective way of forming drug nanocomposites with the help of microwave, which can be scaled up to an industrial level. The method gives an immaculate means of solubilisation by generating drug dispersion at the micro and nanoscale level in natural biodegradable stabilising media. Hence, this study demonstrates the use of BNCs in solubility and dissolution enhancement.


Assuntos
Sistemas de Liberação de Medicamentos , Glipizida/administração & dosagem , Hiperglicemia/prevenção & controle , Hipoglicemiantes/administração & dosagem , Nanocompostos/química , Animais , Disponibilidade Biológica , Química Farmacêutica , Difusão , Sistemas de Liberação de Medicamentos/efeitos adversos , Estabilidade de Medicamentos , Glipizida/química , Glipizida/farmacocinética , Glipizida/uso terapêutico , Química Verde , Interações Hidrofóbicas e Hidrofílicas , Hiperglicemia/sangue , Hiperglicemia/metabolismo , Hipoglicemiantes/química , Hipoglicemiantes/farmacocinética , Hipoglicemiantes/uso terapêutico , Cinética , Masculino , Micro-Ondas , Nanocompostos/efeitos adversos , Nanocompostos/efeitos da radiação , Ratos , Ratos Wistar , Solubilidade , Tensoativos/química , Viscosidade
9.
Pharm Dev Technol ; 18(4): 950-6, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-22200332

RESUMO

In the present study, novel environmentally responsive ophthalmic drug delivery system composed of two gelling polymers with different phase transition mechanisms was developed in order to obtain sustained drug release in ocular cavity. Combination of polyacrylic acid (carbopol 934P) and xanthan gum was investigated as ophthalmic vehicle and assessed for its in vitro and in vivo performance. Different ratios of these polymers were used to prepare environmentally responsive ophthalmic drug delivery system by simple mixing procedure. Developed formulation was assessed for physical tests such as appearance/clarity, pH, gelation; and performance characteristics such as drug content, rheological measurement, in vitro release, antimicrobial efficiency, in vivo studies for eye irritation, residence time estimation. Prepared formulation showed agreeable appearance/clarity, acceptable pH and good gelation property. In vitro and in vivo studies demonstrated adequate drug content, desired rheological behavior and reasonable in vitro and in vivo drug release property. In conclusion, the optimum concentration of polymers results in increased residence time and sustained drug release. On the basis of these findings, environmentally responsive system based on combination of carbopol and xanthan gum may be considered as a promising tool for ophthalmic delivery.


Assuntos
Antibacterianos/administração & dosagem , Sistemas de Liberação de Medicamentos , Excipientes/química , Ofloxacino/administração & dosagem , Acrilatos/química , Administração Oftálmica , Animais , Antibacterianos/química , Antibacterianos/toxicidade , Preparações de Ação Retardada , Composição de Medicamentos , Feminino , Géis , Concentração de Íons de Hidrogênio , Ofloxacino/química , Ofloxacino/toxicidade , Transição de Fase , Polissacarídeos Bacterianos/química , Coelhos , Reologia , Fatores de Tempo
10.
PDA J Pharm Sci Technol ; 66(2): 151-60, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22492600

RESUMO

The main objective of the present research work was to develop a bilayer tablet of metoclopramide hydrochloride (MTH) and diclofenac sodium (DS) in separate layers to avoid incompatibility and thus to maximize the efficacy of both drugs in combination for the effective treatment of migraine headaches. MTH and DS were formulated as immediate and sustained release layers respectively. In vitro dissolution kinetic studies of an optimized (D10) batch of DS in both sustained release layer and bilayer tablet forms show good linearity of regression coefficient 0.9773 (first order equation). The results reveal that an optimized immediate release layer (M5) of MTH and a sustained release layer (D10) of DS might be suitable for the treatment of migraine by sequential release of the two drugs in a bilayer tablet. LAY ABSTRACT: Migraine is a type of recurring headache of moderate to severe intensity associated with gastrointestinal, neurological, and autonomic symptoms. In migraine, a combination of pretreatment with antiemetics is required for symptomatic treatment, when nausea and vomiting are severe. In our present research, we have selected the metoclopramide hydrochloride (MTH) active ingredient for study because it has an antiemetic effect and is a prokinetic agent. MTH is more effective to counteract gastric stasis associated with migraine, and it enhances the rate of absorption of non-steroidal anti-inflammatory drugs (NSAIDs). In the present investigation we combine MTH and a second active ingredient, diclofenac sodium, as a formulated bilayer tablet to prevent degradation of MTH.


Assuntos
Diclofenaco , Metoclopramida , Antieméticos/administração & dosagem , Preparações de Ação Retardada , Diclofenaco/administração & dosagem , Cinética , Metoclopramida/uso terapêutico , Comprimidos
11.
J Microencapsul ; 29(1): 72-82, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22034955

RESUMO

The objective of this study was to investigate a novel hydrogel plug using isolated root mucilage of Sterculia urens to obtain a desired lag time for an oral chronotherapeutic colon-specific pulsatile drug delivery of indomethacin. Pulsatile drug delivery was developed using chemically treated hard gelatin capsule bodies filled with eudragit multiparticulates of indomethacin, and sealed with different hydrogel plugs (root mucilage of S. urens, xanthan gum, guar gum, HPMC K4M and combination of maltodextrin with guar gum). Indomethacin multiparticulates were prepared using extrusion spheronization, spray drying and solvent evaporation techniques with Eudragit® L-100 and S-100 (1:2) by varying drug-to-polymer ratio. After oral administration, the water-soluble cap of capsule dissolved in the intestinal fluid and the hydrogel plug swells. After a controlled time, the swollen plug subsequently ejected from the dosage form, releases the contents of the capsule. The formulation factors affecting the drug release were concentration and types of hydrogel plug used. In vivo gamma scintigraphy study in healthy rabbits proved the capability of the system to release drug in lower parts of the gastrointestinal tract after a programmed lag time. This study demonstrates that the indomethacin multiparticulates could be successfully colon-targeted by the design of time and pH-dependent modified chronopharmaceutical formulation. In conclusion, the investigated novel hydrogel plug could be a valuable tool for achieving desired lag time.


Assuntos
Sistemas de Liberação de Medicamentos , Hidrogéis , Sterculia/química , Varredura Diferencial de Calorimetria , Técnicas In Vitro , Microscopia Eletrônica de Varredura , Difração de Pó , Cintilografia
12.
Eur J Med Chem ; 47(1): 278-82, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22088956

RESUMO

Tuberculosis, the infection on the verge of eradication once, is now a great threat to mankind. Emergence of MDR and XDR-TB synergised with HIV and other immune-compressive diseases have increased the life threatening capacities of the disease. A small molecule has been identified here, which showed potent anti-tubercular activity. The identified hit compound has also been proved active against nearly 25 clinical isolates comparable with isoniazid.


Assuntos
Antituberculosos/química , Antituberculosos/farmacologia , Descoberta de Drogas , Tuberculose Extensivamente Resistente a Medicamentos/tratamento farmacológico , Oxidiazóis/química , Oxidiazóis/farmacologia , Antituberculosos/uso terapêutico , Antituberculosos/toxicidade , Células Hep G2 , Humanos , Testes de Sensibilidade Microbiana , Mycobacterium tuberculosis/efeitos dos fármacos , Oxidiazóis/uso terapêutico , Oxidiazóis/toxicidade
13.
Pharm Dev Technol ; 16(1): 65-74, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20088679

RESUMO

The aim of the present study was to formulate a self-emulsifying drug delivery system of atorvastatin calcium and its characterization including in vitro and in vivo potential. The solubility of atorvastatin calcium was determined in various vehicles such as Captex 355, Captex 355 EP/NF, Ethyl oleate, Capmul MCM, Capmul PG-8, Gelucire 44/14, Tween 80, Tween 20, and PEG 400. Pseudoternary phase diagrams were plotted on the basis of solubility data of drug in various components to evaluate the microemulsification region. Formulation development and screening was carried out based on results obtained from phase diagrams and characteristics of resultant microemulsion. Prepared formulations were tested for microemulsifying properties and evaluated for clarity, precipitation, viscosity determination, drug content and in vitro dissolution. The optimized formulation further evaluated for particle size distribution, zeta potential, stability studies and in vivo potential. In vivo performance of the optimized formulation was evaluated using a Triton-induced hypercholesterolemia model in male Albino Wistar rats. The formulation significantly reduced serum lipid levels as compared with atorvastatin calcium. Thus studies illustrated the potential use for the delivery of hydrophobic drug such as atorvastatin calcium by oral route.


Assuntos
Sistemas de Liberação de Medicamentos , Ácidos Heptanoicos/química , Ácidos Heptanoicos/farmacocinética , Inibidores de Hidroximetilglutaril-CoA Redutases/química , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacocinética , Pirróis/química , Pirróis/farmacocinética , Administração Oral , Animais , Atorvastatina , Disponibilidade Biológica , Química Farmacêutica , Estabilidade de Medicamentos , Emulsões , Ácidos Heptanoicos/administração & dosagem , Ácidos Heptanoicos/farmacologia , Inibidores de Hidroximetilglutaril-CoA Redutases/administração & dosagem , Lipídeos/sangue , Masculino , Tamanho da Partícula , Transição de Fase , Pirróis/administração & dosagem , Pirróis/farmacologia , Ratos , Solubilidade , Propriedades de Superfície , Viscosidade
14.
J Indian Prosthodont Soc ; 11(1): 63-6, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22379308

RESUMO

Impressions are important sources of cross contamination between patients and dental laboratories. As a part of infection control impressions contaminated with variety of micro-organisms via blood and oral secretions should be cleaned and disinfected or sterilized before being handled in dental laboratory. The purpose of this study was to determine the effect of autoclaving on dimensional stability of elastomeric impression material (polyvinyl siloxane-Affinis). In this in vitro study standardized stainless steel die as per ADA specification number 19 was fabricated. Polyvinyl siloxane (Affinis) light body and putty viscosity elastomeric impression materials were used. A total of 40 impressions of the stainless steel die were made and numeric coding system was used to identify the samples. Measurements were made using a measuring microscope. Distance between the cross lines CD and C'D' reproduced in the impression were measured before autoclaving, immediately after autoclaving and 24 hours after autoclaving and dimensional change was calculated. The data obtained was subjected to statistical analysis. The mean difference in dimensional change between the three groups was not statistically significant (P > 0.05). However the results revealed that there was higher mean dimensional change immediately after autoclaving when compared to the other 2 time intervals. It is desirable to delay the casting of an autoclavable elastomeric impression material by about 24 hours. Though disinfection of impression is routinely followed autoclaving of impression is an effective method of sterilization.

15.
Drug Deliv ; 17(5): 343-51, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20429842

RESUMO

The aim of the present study was to develop theophylline fast release enteric-coated pellets as a pulsatile drug delivery to the colon. The novelty of this work is the combination of pH and time-dependant enteric polymers as a single coating for the development of multiparticulate formulation. Theophylline pellets were optimized by applying a 2-factors 3-levels full factorial design. Continuous dissolution studies were carried out in simulated gastric, intestinal, and colonic fluid with pH 1.2 (0.1 N HCl), pH 7.4 and pH 6.8 (phosphate buffer), respectively. The lag time prior to the drug release was highly affected by combination of two factors, i.e. the percentage of Eudragit RL100 in polymer mixture and coating level. The formulation containing Eudragit RL100 and Eudragit S100 with a ratio of 4:1 and coating level of 12%w/w was found to be optimum. The results of serum study in New Zealand rabbits showed that the developed formulation provided a significant lag phase of 5 h. The present study demonstrates that the theophylline enteric-coated pellets could be successfully colon targeted by the design of pH- and time-dependant modified chronopharmaceutical formulation. In conclusion, pulsatile drug release over a period of 3-12 h is consistent with the requirements for chronopharmaceutical drug delivery.


Assuntos
Broncodilatadores/administração & dosagem , Colo/metabolismo , Sistemas de Liberação de Medicamentos , Teofilina/administração & dosagem , Resinas Acrílicas/química , Animais , Asma/tratamento farmacológico , Broncodilatadores/uso terapêutico , Preparações de Ação Retardada , Cronofarmacoterapia , Excipientes/química , Concentração de Íons de Hidrogênio , Masculino , Ácidos Polimetacrílicos/química , Coelhos , Solubilidade , Teofilina/uso terapêutico , Fatores de Tempo
16.
Pharm Dev Technol ; 15(6): 666-8, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19905989

RESUMO

The objective of the present study was to correlate the results of the in vitro release of a previously reported pulsatile drug delivery system with the in vivo radio imaging study. The formulated drug delivery system containing pellets of barium sulphate was administered to rabbits after overnight fast. Formulated dosage form, previously evaluated for in vitro drug release study, showed drug release after 6-10 h of lag time depending on the hardness as well as the thickness of the plug. Radio imaging study also showed that the plug in the capsule drug delivery system remains intact for the period of 6 h. Thus, the formulated drug delivery system is capable of delaying release in vitro as well as in rabbits for 6 hours.


Assuntos
Sulfato de Bário/administração & dosagem , Meios de Contraste/administração & dosagem , Sistemas de Liberação de Medicamentos , Polímeros/química , Animais , Sulfato de Bário/química , Meios de Contraste/química , Preparações de Ação Retardada , Masculino , Pulsoterapia , Coelhos , Fatores de Tempo
17.
Pharm Dev Technol ; 15(1): 57-63, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-19552544

RESUMO

The aim of the present study was to develop fast-release enteric-coated tablets for pulsatile drug delivery to the colon. The novelty of this work is a combination of pH- and time-dependant enteric polymers as a single coating. Eudragit S100 was used as a pH-dependant polymer and eudragit RL100 was used as a time-dependant polymer. Theophylline was taken as a model drug. Dissolution studies of enteric-coated tablets were performed with different media having a pH of 1.2, 7.4, and 6.8. Results of the dissolution data show that drug release in the colon could be controlled by using eudragit RL100 eudragit S100. The lag time prior to the drug release was highly affected by a combination of two factors: The percentage of eudragit RL100 and coating level. The optimum formulation was found to be one containing eudragit RL100 and eudragit S100 with a ratio of 60:40 of polymer and coating level of 4.66% w/w. The present study demonstrates that the theophylline enteric-coated tablets could be successfully formulated as a pulsatile drug delivery by the design of a time- and pH-dependant modified chronopharmaceutical formulation. In conclusion, pulsatile drug release over a period of 2-12 hours, consistent with the requirements for chronopharmaceutical drug delivery, can be achieved by using time- and pH-dependant polymers.


Assuntos
Resinas Acrílicas , Química Farmacêutica , Sistemas de Liberação de Medicamentos , Polímeros , Teofilina/química , Asma/tratamento farmacológico , Broncodilatadores/administração & dosagem , Broncodilatadores/química , Broncodilatadores/uso terapêutico , Excipientes/química , Concentração de Íons de Hidrogênio , Ácidos Polimetacrílicos , Fluxo Pulsátil , Solubilidade , Comprimidos com Revestimento Entérico , Tecnologia Farmacêutica , Teofilina/administração & dosagem , Teofilina/uso terapêutico , Fatores de Tempo
18.
Pharm Dev Technol ; 15(6): 653-7, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20020823

RESUMO

Gellan gum-based mucoadhesive microspheres of ondansetron hydrochloride for intranasal systemic delivery were prepared to avoid first pass effect, an alternative route of administration to injection and to enhance systemic bioavailability of ondansetron hydrochloride. The microspheres were prepared using spray method. The evaluation results of microspheres were reported in our previous study. The aim of this work was to study the in vivo performance of mucoadhesive microspheres in comparison with oral and intravenous preparations of ondansetron hydrochloride. The nasal delivery system gave increased AUC(0-240) and C(max) as compared to those of oral delivery. In conclusion, the gellan gum-based microsphere formulation of ondansetron hydrochloride with mucoadhesive properties with increased permeation rate is promising for prolonging nasal residence time and thereby nasal absorption.


Assuntos
Portadores de Fármacos/química , Ondansetron/farmacocinética , Polissacarídeos Bacterianos/química , Antagonistas da Serotonina/farmacocinética , Adesividade , Administração Intranasal , Administração Oral , Animais , Área Sob a Curva , Disponibilidade Biológica , Sistemas de Liberação de Medicamentos , Injeções Intravenosas , Microesferas , Ondansetron/administração & dosagem , Coelhos , Antagonistas da Serotonina/administração & dosagem
19.
J Microencapsul ; 26(8): 711-21, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19888880

RESUMO

The purpose of present research work was to develop mucoadhesive microspheres for nasal delivery with the aim to avoid hepatic first-pass metabolism, improve therapeutic efficacy and enhance residence time. For the treatment of migraine, hydroxypropyl methylcellulose (HPMC) K4M and K15M based microspheres containing sumatriptan succinate (SS) were prepared by spray-drying technique. The microspheres were evaluated with respect to the yield, particle size, incorporation efficiency, swelling property, in vitro mucoadhesion, in vitro drug release, histological study and stability. Microspheres were characterized by differential scanning calorimetry, scanning electron microscopy and X-ray diffraction study. It was found that the particle size, swelling ability and incorporation efficiency of microspheres increases with increasing drug-to-polymer ratio. HPMC-based microspheres show adequate mucoadhesion and do not have any destructive effect on nasal mucosa. On the basis of these results, SS microspheres based on HPMC may be considered as a promising nasal delivery system.


Assuntos
Microesferas , Sumatriptana/administração & dosagem , Adesividade , Administração Intranasal , Derivados da Hipromelose , Metilcelulose/análogos & derivados , Transtornos de Enxaqueca/tratamento farmacológico , Mucosa Nasal/metabolismo , Agonistas do Receptor de Serotonina , Vasoconstritores
20.
Pharm Dev Technol ; 14(2): 226-32, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19519195

RESUMO

Gellan gum microspheres of ondansetron hydrochloride, for intranasal delivery, were prepared to avoid the first pass metabolism as an alternative therapy to parentral, and to improve therapeutic efficiency in treatment of nausea and vomiting. The microspheres were prepared using conventional spray-drying method. The microspheres were evaluated for characteristics like particle size, incorporation efficiency, swelling ability, zeta potential, in-vitro mucoadhesion, thermal analysis, XRD study and in-vitro drug release. Treatment of in-vitro data to different kinetic equations indicated diffusion controlled drug delivery from gellan gum microspheres. The results of DSC and XRD studies revealed molecular amorphous dispersion of ondansetron into the gellan gum microspheres.


Assuntos
Portadores de Fármacos/química , Microesferas , Mucosa Nasal/efeitos dos fármacos , Ondansetron/administração & dosagem , Polissacarídeos Bacterianos/química , Antagonistas da Serotonina/administração & dosagem , Adesividade , Administração Intranasal , Animais , Varredura Diferencial de Calorimetria , Portadores de Fármacos/administração & dosagem , Mucosa Nasal/metabolismo , Mucosa Nasal/patologia , Ondansetron/química , Ondansetron/farmacocinética , Tamanho da Partícula , Polissacarídeos Bacterianos/administração & dosagem , Antagonistas da Serotonina/química , Antagonistas da Serotonina/farmacocinética , Ovinos , Eletricidade Estática , Propriedades de Superfície , Difração de Raios X
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