Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Eur J Pharm Biopharm ; 203: 114480, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39222674

RESUMO

Efficient telmisartan delivery for hypertension management requires the incorporation of meglumine and/or sodium hydroxide as an alkalizer in the formulation. Long-term use of powerful alkalis with formulation as part of chronic therapy can cause metabolic alkalosis, ulcers, diarrhea, and body pain. Here, we aimed to design a telmisartan formulation without alkalizers. Telmisartan properties were tailor-made by microfluidizer-based physical modification. After microfluidization, telmisartan nanosuspension was lyophilized to obtain telmisartan premix powder. The optimized telmisartan nanosuspension had an average particle size of 579.85 ± 32.14 nm. The lyophilized premix was characterized by FT-IR, DSC, and PXRD analysis to ensure its physicochemical characteristics. The solubility analysis of premix showed 2.2 times, 2.3 times, and 6 times solubility improvement in 0.1 N HCl, phosphate buffer pH 7.5, and pH 6.8 compared to pure telmisartan. A 3D in-vitro Caco-2 model was developed to compare apparent permeability of API and powder premix. It showed that the powder premix was more permeable than pure API. The tablet formulation prepared from the telmisartan premix showed a dissolution profile comparable to that of the marketed formulation. The technique present herein can be used as a platform technology for solubility and permeability improvement of similar classes of molecules.


Assuntos
Tamanho da Partícula , Permeabilidade , Solubilidade , Telmisartan , Telmisartan/administração & dosagem , Telmisartan/farmacocinética , Telmisartan/química , Humanos , Células CACO-2 , Composição de Medicamentos/métodos , Absorção Intestinal/efeitos dos fármacos , Pós/química , Concentração de Íons de Hidrogênio , Nanopartículas/química , Química Farmacêutica/métodos , Liberação Controlada de Fármacos , Função da Barreira Intestinal
2.
Int J Pharm ; 665: 124672, 2024 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-39245084

RESUMO

Dasatinib (DAB) has been explored for repurposing in the treatment of breast cancer (BC) due to its known effectiveness in treating leukemia, in addition to its role as a tyrosine kinase inhibitor. Gallic acid (GA) was chosen as a co-former due to its anticancer potential in BC, as demonstrated in several previous studies. DAB is a low-solubility drug, which is a significant hurdle for its oral bioavailability. To address this limitation, a DAB and GA co-amorphous (DAB-GA-CA) system was developed using liquid-assisted grinding and ball mill technology to enhance solubility, bioavailability, and anti-tumor efficacy. Physical characterization investigation revealed that the emergence of the halo diffractogram in PXRD, single glass transition temperature (Tg) value at 111.7 °C in DSC thermogram, and irregularly shaped blocks with loose, porous surfaces in SEM analysis indicated the formation of the DAB-GA-CA system at 1:1 M ratio. Furthermore, FTIR, Raman spectroscopy, in-silico molecular docking, and molecular dynamic studies confirmed the intermolecular hydrogen connections between DAB and GA. Moreover, the outcomes of the ligands (DAB and GA) and receptors (BCL-2, mTOR, estrogen receptor, and HER-2) docking studies demonstrated that both DAB and GA could interact with those receptors, leading to preventive action on BC cells. Additionally, the solubility and dissolution rate significantly improved at pH 6.8, and the permeability study indicated that DAB-GA-CA showed 1.9 times higher apparent permeability compared to crystalline DAB. Furthermore, in vitro cytotoxicity assessments of the DAB-GA-CA system revealed 3.42 times lower IC50 than free DAB. The mitochondrial membrane depolarization, apoptotic index, and reactive oxygen species formation in MCF-7 cells were also notably higher in the DAB-GA-CA system than in free DAB. Hence, this research suggests that the DAB-GA-CA system could substantially enhance oral delivery, solubility, and therapeutic efficacy.

3.
J Mater Chem B ; 2024 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-39171482

RESUMO

Stem cells are an essential consideration in the fields of tissue engineering and regenerative medicine. Understanding how nanoengineered biomaterials and mesenchymal stem cells (MSCs) interact is crucial for their role in bone regeneration. Taking advantage of the structural stability of selenium nanoparticles (Se-NPs) and biological properties of natural polymers, Se-NPs-functionalized, injectable, thermoresponsive hydrogels with an interconnected molecular structure were prepared to identify their role in the osteogenic differentiation of different types of mesenchymal stem cells. Further, comprehensive characterization of their structural and biological properties was performed. The results showed that the hydrogels undergo a sol to gel transition with the help of ß-glycerophosphate, while functionalization with Se-NPs significantly enhances their biological response through stabilizing their polymeric structure by forming Se-O covalent bonds. Further results suggest that Se-NPs enhance the differentiation of MSCs toward osteogenic lineage in both the 2D as well as 3D. We demonstrated that the Se-NPs-functionalized hydrogels could enhance the differentiation of osteoporotic bone-derived MSCs. We also focused on specific cell surface marker expression (CD105, CD90, CD73, CD45, CD34) based on the exposure of healthy rats' bone marrow-derived stem cells (BMSCs) to the Se-NP-functionalized hydrogels. This study provides essential evidence for pre-clinical/clinical applications, highlighting the potential of the nanoengineered biocompatible elastic hydrogels for bone regeneration in diseased bone.

4.
J Mater Chem B ; 12(36): 8843-8867, 2024 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-39162395

RESUMO

Breast cancer (BC) is the second deadliest cancer after lung cancer. Similar to all cancers, it is also driven by a 3D microenvironment. The extracellular matrix (ECM) is an essential component of the 3D tumor micro-environment, wherein it functions as a scaffold for cells and provides metabolic support. BC is characterized by alterations in the ECM. Various studies have attempted to mimic BC-specific ECMs using artificial materials, such as Matrigel. Nevertheless, research has proven that naturally derived decellularized extracellular matrices (dECMs) are superior in providing the essential in vivo-like cues needed to mimic a cancer-like environment. Developing in vitro 3-D BC models is not straightforward and requires extensive analysis of the data established by researchers. For the benefit of researchers, in this review, we have tried to highlight all developmental studies that have been conducted by various scientists so far. The analysis of the conclusions drawn from these studies is also discussed. The advantages and drawbacks of the decellularization methods employed for generating BC scaffolds will be covered, and the review will shed light on how dECM scaffolds help develop a BC environment. The later stages of the article will also focus on immunogenicity issues arising from decellularization and the origin of the tissue. Finally, this review will also discuss the biofabrication of matrices, which is the core part of the bioengineering process.


Assuntos
Neoplasias da Mama , Matriz Extracelular Descelularizada , Alicerces Teciduais , Humanos , Neoplasias da Mama/patologia , Alicerces Teciduais/química , Matriz Extracelular Descelularizada/química , Feminino , Medicina de Precisão , Antineoplásicos/química , Antineoplásicos/farmacologia , Matriz Extracelular/química , Matriz Extracelular/metabolismo , Ensaios de Seleção de Medicamentos Antitumorais , Animais , Engenharia Tecidual , Avaliação Pré-Clínica de Medicamentos , Microambiente Tumoral
5.
Drug Discov Today ; 29(6): 104011, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38705511

RESUMO

Active pharmaceutical ingredients (APIs) and excipients can be carefully combined in premix-based materials before being added to dosage forms, providing a flexible platform for the improvement of drug bioavailability, stability, and patient compliance. This is a promising and transformative approach in novel and generic product development, offering both the potential to overcome challenges in the delivery of complex APIs and viable solutions for bypassing patent hurdles in generic product filing. We discuss the different types of premixes; manufacturing technologies such as spray drying, hot melt extrusion, wet granulation, co-crystal, co-milling, co-precipitation; regulatory filing opportunities; and major bottlenecks in the use of premix materials in different aspects of pharmaceutical product development.


Assuntos
Sistemas de Liberação de Medicamentos , Humanos , Tecnologia Farmacêutica/métodos , Preparações Farmacêuticas/química , Excipientes/química , Desenvolvimento de Medicamentos/métodos
6.
Int J Biol Macromol ; 271(Pt 1): 132606, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38788875

RESUMO

The present investigation was aimed to fabricate and optimize extended-release beads of diclofenac sodium based on an ion-cross-linked matrix of pectin (PTN) and taro (Colocasia esculenta) stolon polysaccharide (TSP) with 23 full factorial design. Total polysaccharide concentration (TPC), polysaccharide ratio (PR), and cross-linker concentration ([CaCl2]) were taken as independent factors with two levels of each. Initially, TSP was extracted, purified, and characterized. Fourier-transform infrared spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC) showed drug-polymer compatibility. The study also revealed the significant positive effect of TSP on drug entrapment efficiency (DEE) and sustaining drug release. The response variables (DEE, cumulative % drug-release at 1, 2, 4, 6, and 10 h, release-constant, time for 50 % and 90 % drug release (T50%, T90%), release-similarity factor (f2), and difference factor (f1) were analyzed, and subsequently, independent fabrication variables were numerically optimized by Design-Expert software (Version-13; Stat-Ease Inc., Minneapolis). The optimized batch exhibited appreciable DEE of 88.5 % (± 2.2) and an extended-release profile with significantly higher T50%, T90%, and release-similarity factor (f2) of 4.7 h, 11.4 h, and 71.6, respectively. Therefore, the study exhibited successful incorporation of the novel TSP as a potential alternative adjunct polysaccharide in the pectin-based ion-cross-linked inter-penetrating polymeric network for extended drug release.


Assuntos
Colocasia , Preparações de Ação Retardada , Diclofenaco , Liberação Controlada de Fármacos , Pectinas , Diclofenaco/química , Pectinas/química , Colocasia/química , Portadores de Fármacos/química , Polissacarídeos/química , Cálcio/química , Microesferas , Espectroscopia de Infravermelho com Transformada de Fourier
7.
Biomed Mater ; 19(3)2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38574581

RESUMO

In terms of biomedical tools, nanodiamonds (ND) are a more recent innovation. Their size typically ranges between 4 to 100 nm. ND are produced via a variety of methods and are known for their physical toughness, durability, and chemical stability. Studies have revealed that surface modifications and functionalization have a significant influence on the optical and electrical properties of the nanomaterial. Consequently, surface functional groups of NDs have applications in a variety of domains, including drug administration, gene delivery, immunotherapy for cancer treatment, and bio-imaging to diagnose cancer. Additionally, their biocompatibility is a critical requisite for theirin vivoandin vitrointerventions. This review delves into these aspects and focuses on the recent advances in surface modification strategies of NDs for various biomedical applications surrounding cancer diagnosis and treatment. Furthermore, the prognosis of its clinical translation has also been discussed.


Assuntos
Nanodiamantes , Neoplasias , Humanos , Nanodiamantes/química , Nanodiamantes/uso terapêutico , Sistemas de Liberação de Medicamentos/métodos , Neoplasias/terapia , Neoplasias/tratamento farmacológico , Diagnóstico por Imagem/métodos , Imunoterapia
8.
J Exp Clin Cancer Res ; 42(1): 343, 2023 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-38102637

RESUMO

In vitro models are necessary to study the pathophysiology of the disease and the development of effective, tailored treatment methods owing to the complexity and heterogeneity of breast cancer and the large population affected by it. The cellular connections and tumor microenvironments observed in vivo are often not recapitulated in conventional two-dimensional (2D) cell cultures. Therefore, developing 3D in vitro models that mimic the complex architecture and physiological circumstances of breast tumors is crucial for advancing our understanding of the illness. A 3D scaffold-free in vitro disease model mimics breast cancer pathophysiology by allowing cells to self-assemble/pattern into 3D structures, in contrast with other 3D models that rely on artificial scaffolds. It is possible that this model, whether applied to breast tumors using patient-derived primary cells (fibroblasts, endothelial cells, and cancer cells), can accurately replicate the observed heterogeneity. The complicated interactions between different cell types are modelled by integrating critical components of the tumor microenvironment, such as the extracellular matrix, vascular endothelial cells, and tumor growth factors. Tissue interactions, immune cell infiltration, and the effects of the milieu on drug resistance can be studied using this scaffold-free 3D model. The scaffold-free 3D in vitro disease model for mimicking tumor pathophysiology in breast cancer is a useful tool for studying the molecular basis of the disease, identifying new therapeutic targets, and evaluating treatment modalities. It provides a more physiologically appropriate high-throughput platform for screening large compound library in a 96-384 well format. We critically discussed the rapid development of personalized treatment strategies and accelerated drug screening platforms to close the gap between traditional 2D cell culture and in vivo investigations.


Assuntos
Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/patologia , Células Endoteliais/metabolismo , Esferoides Celulares/patologia , Matriz Extracelular/metabolismo , Organoides/metabolismo , Microambiente Tumoral
9.
Eur J Pharm Sci ; 190: 106551, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37562551

RESUMO

The establishment of drug product stability and sameness is the heart of generic formulation development. For regulatory filing, various instrumental methods are used on a case basis to establish the generic and innovator product sameness in multiple aspects. Here in the present study, we explored the applicability of the Time-correlated single photon counting (TCS-PC) technique as a fast, reliable, and nondestructive method for establishing the sameness of three different categories of injectable formulations, namely, Amphotericin B liposome for injection, enoxaparin injection, and iron sucrose injection. All three category formulations were evaluated in their native and artificially induced post degradation state to identify the discrimination power of the used instrumental techniques. The degradation of materials were confirmed by high performance liquid chromatography (HPLC). Based on the product category, pre and post-degradation samples were evaluated by selective instrumental methods like differential scanning calorimetry (DSC), nuclear magnetic resonance (NMR), fluorescence spectroscopy, particle size analysis by dynamic light scattering (DLS), small angle X-ray scattering (SAXS), Raman spectroscopy, inductively coupled plasma optical-emission spectrometry (ICP-OES) and circular dichroism study. All pre and post-degradation samples were further analyzed by TCS-PC. We observed that, TCS-PC can identify the differences between the initial and post degradation samples in very less time with promising discrimination power across the different injectable formulation types. Thus TCS-PC can be used as a fast and promising stability or sameness evaluation tool for different injectable drug products.


Assuntos
Difração de Raios X , Espalhamento a Baixo Ângulo , Estabilidade de Medicamentos
10.
Mol Pharm ; 20(8): 3791-3803, 2023 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-37459158

RESUMO

Disintegration time (DT) and rate of drug dissolution in different media are among the most widely studied crucial parameters for various types of drug products. In the ever-evolving landscape of generic formulation development, dissolution comparison of reference and test products is the major reliable in vitro method of establishing product similarity. This is one of the most widely accepted methods of proving pharma equivalency between two drug products. A well-studied match between the disintegration and dissolution profile of the test and reference formulations can ensure in vitro product similarity. Various statistical approaches have been employed to establish product performance similarity; among them, the similarity factor (f2) calculation based approach is the most widely accepted and explored method to date. However, the f2 statistics fail to predict the similarity of batches with unit-to-unit variability. Bootstrap statistical analysis of dissolution data between the test and reference products was introduced to overcome the problems associated with batches with unit variability. Bootstrap can also be applied to extract statistically significant results by treating a series of data from different batches, which can further help to understand the trend. The current review depicts different case study based approaches to show the applications of bootstrap statistics in disintegration and dissolution similarity evaluation for both conventional and additively manufactured solid dosage forms. It is concluded that bootstrap statistics can be a very promising and reliable data analytical tool for establishing in vitro product similarity for both conventional and additively manufactured formulations with a high level of intraunit variability.


Assuntos
Medicamentos Genéricos , Solubilidade , Liberação Controlada de Fármacos , Técnicas In Vitro , Comprimidos
11.
Curr Pharm Des ; 21(20): 2771-83, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25925119

RESUMO

Drug-in-adhesive transdermal drug delivery matrix exploits intimate contact of the carrier with stratum corneum, the principal skin barrier to drug transport, to deliver the actives across the skin and into the systemic circulation. The main application challenges of drug-in-adhesive matrix lie in the physicochemical properties of skin varying with age, gender, ethnicity, health and environmental condition of patients. This in turn poses difficulty to design a universal formulation to meet the intended adhesiveness, drug release and drug permeation performances. This review focuses on pressure-sensitive adhesives, and their adhesiveness and drug release/permeation modulation mechanisms as a function of adhesive molecular structure and formulation attributes. It discusses approaches to modulate adhesive tackiness, strength, elasticity, hydrophilicity, molecular suspension capability and swelling capacity, which contribute to the net effect of adhesive on skin bonding, drug release and drug permeation.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Desenho de Fármacos , Preparações Farmacêuticas/administração & dosagem , Pele , Tecnologia Farmacêutica/métodos , Adesivos Teciduais/química , Adesividade , Administração Cutânea , Animais , Liberação Controlada de Fármacos , Humanos , Preparações Farmacêuticas/química , Preparações Farmacêuticas/metabolismo , Pressão , Pele/anatomia & histologia , Pele/química , Pele/metabolismo , Absorção Cutânea
12.
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
13.
Int J Biol Macromol ; 72: 883-93, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25307127

RESUMO

Strategically developed natural polymer-based controlled release multiparticulate drug delivery systems have gained special interest for "spatial placement" and "temporal delivery" of drug molecules. In our earlier study, locust bean gum-poly(vinyl alcohol) interpenetrating polymer network (LBG-PVA IPN), carboxymethylated locust bean gum-poly(vinyl alcohol) interpenetrating polymer network (CMLBG-PVA IPN) and acrylamide grafted locust bean gum-poly(vinyl alcohol) interpenetrating polymer network (Am-g-LBG-PVA IPN) were prepared and characterized. The present study deals with accelerating stability testing, comparative bio-safety and single dose in vivo pharmacokinetic study of all three IPN microspheres for controlled oral delivery of buflomedil hydrochloride (BH). From the stability study, it was observed that the particles were stable throughout the study period. From toxicity and biodegradability study it was proved that the microspheres were safe for internal use and complied with bio-safety criterion. From the in vivo pharmacokinetic study in rabbits, it was observed that the CMLBG-PVA IPN microspheres possessed almost similar Tmax value with BH oral suspension. However, in comparison between the LBG-PVA and Am-g-LBG-PVA IPN microspheres, the later showed well controlled release property than the first in biological condition. Thus, this type of delivery system might be useful to achieve the lofty goals of the controlled release drug delivery.


Assuntos
Galactanos/administração & dosagem , Galactanos/química , Mananas/administração & dosagem , Mananas/química , Microesferas , Gomas Vegetais/administração & dosagem , Gomas Vegetais/química , Álcool de Polivinil/química , Administração Oral , Animais , Varredura Diferencial de Calorimetria , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Estabilidade de Medicamentos , Feminino , Galactanos/efeitos adversos , Mananas/efeitos adversos , Camundongos , Gomas Vegetais/efeitos adversos , Pirrolidinas/administração & dosagem , Pirrolidinas/farmacocinética , Coelhos , Espectroscopia de Infravermelho com Transformada de Fourier , Testes de Toxicidade Aguda , Difração de Raios X
14.
Carbohydr Polym ; 98(1): 1083-94, 2013 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-23987450

RESUMO

Acrylamide grafted copolymer of locust bean gum was prepared by microwave irradiation using ceric ammonium nitrate as redox initiator. The grafting process was optimized in terms of irradiation time, amount of initiator and acrylamide by using constant amount of native locust bean gum. The grafted gum was characterized by Fourier transform infrared spectroscopy (FT-IR), (13)C nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), X-ray diffraction study (XRD), differential scanning calorimetry (DSC), elemental analysis, contact angle, viscosity, molecular weight, swelling and biodegradability studies. The grafted gum was found to be biodegradable and non-toxic. It was further used to prepare controlled-release matrix tablet of buflomedil hydrochloride. The in vitro release profile of the tablet showed the rate controlling property of acrylamide grafted locust bean gum was similar to that of hydroxypropyl methylcellulose (HPMC-K15M).


Assuntos
Acrilamida/química , Portadores de Fármacos/química , Portadores de Fármacos/síntese química , Galactanos/química , Mananas/química , Micro-Ondas , Gomas Vegetais/química , Animais , Técnicas de Química Sintética , Portadores de Fármacos/toxicidade , Feminino , Meia-Vida , Camundongos , Pirrolidinas/sangue , Pirrolidinas/química , Solubilidade , Testes de Toxicidade , Viscosidade , Água/química
15.
Carbohydr Polym ; 94(1): 456-67, 2013 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-23544563

RESUMO

A novel interpenetrating polymer network (IPN) microspheres of locust bean gum (LBG) and poly (vinyl alcohol) (PVA) was developed for oral controlled release of buflomedil hydrochloride (BH) by emulsion crosslinking method using glutaraldehyde as crosslinker. The effects of gum-polymer ratio, concentration of crosslinker and internal phase viscosity were evaluated thoroughly. Drug entrapment efficiency, particle size distribution, swelling property and in vitro release characteristics with kinetic modelling of microspheres were evaluated. The microspheres were characterised by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), solid state C(13) NMR, X-ray diffraction study (XRD) and differential scanning colorimetry (DSC). The microspheres showed control release property without showing any incompatibility in IPN device. Hence, IPN microspheres of LBG and PVA can be used as a potential carrier for controlled oral delivery of highly water soluble drugs like BH.


Assuntos
Preparações de Ação Retardada/química , Portadores de Fármacos/química , Galactanos/química , Mananas/química , Gomas Vegetais/química , Álcool de Polivinil/química , Varredura Diferencial de Calorimetria , Configuração de Carboidratos , Sequência de Carboidratos , Composição de Medicamentos , Glutaral/química , Concentração de Íons de Hidrogênio , Cinética , Espectroscopia de Ressonância Magnética , Microesferas , Dados de Sequência Molecular , Tamanho da Partícula , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Viscosidade
16.
J Pharm Pharmacol ; 65(2): 219-29, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23278689

RESUMO

OBJECTIVES: The effect of microwave (MW) irradiation and conventional heating (CH) on solid dispersion (SD) of poorly water-soluble glipizide (GPZ) and polyethylene glycol 4000 (PEG 4000) were studied in detail. METHODS: The chemical stability of GPZ on exposure to MW irradiation and CH was confirmed by high-performance liquid chromatography, Fourier transform infra red spectroscopy, proton nuclear magnetic resonance and mass spectroscopy studies. Comparative bioavailability studies were performed in rabbits using glipizide sustained-release tablets prepared using MW irradiation (MW-SD) or CH (CH-SD), with Glytop 2.5 mg SR as a reference. KEY FINDINGS: The MW-assisted melt mixing showed higher efficiency than CH in obtaining a homogeneous mixture having glass transparency. The polymorphic transformation of GPZ in each case was further confirmed by powder X-ray diffraction study. The solubility of GPZ in phosphate buffer pH 6.8 was greater for MW-SD (72.250 ± 0.154 µg/ml) than CH-SD (46 ± 0.201 µg/ml). The MW-SD matrix tablet (2.5 mg) displayed retarded drug release (releasing 99.320 ± 4.992% drug in 12 h). In-vivo pharmacokinetic study in rabbits revealed that the relative bioavailability of GPZ from MW-SD tablets improved greatly (153.73 ± 9.713%). CONCLUSIONS: MW-induced SD technology could be a better alternative to CH-SD for the enhanced solubility and bioavailability of GPZ.


Assuntos
Glipizida/química , Glipizida/farmacocinética , Micro-Ondas , Comprimidos/química , Tecnologia Farmacêutica/métodos , Animais , Disponibilidade Biológica , Preparações de Ação Retardada , Estabilidade de Medicamentos , Vidro/química , Calefação/métodos , Concentração de Íons de Hidrogênio , Polietilenoglicóis/química , Coelhos , Solubilidade , Comprimidos/farmacocinética , Água/química
17.
Carbohydr Polym ; 90(1): 496-506, 2012 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-24751070

RESUMO

The synthesis of acrylamide-grafted-gellan gum was carried out by microwave-assisted free radical polymerization using cerric ammonium nitrate (CAN) as redox initiator. A series of graft copolymers, varying in amount of acrylamide, CAN and microwave irradiation time was prepared. The modified gum was extracted with 20% (v/v) methanol to remove the homopolymer formed during polymerization reaction. These graft copolymers were characterized by FTIR, (13)C NMR, CHN, SEM, rheological studies and DSC studies. Comparison of grafting parameters such as grafting efficiency, percentage grafting and percentage conversion were carried out among various series of graft copolymers and then correlating it with elemental analysis, DSC, viscosity results. The acute oral toxicity study of grated gum was evaluated as per OECD guideline. Tablets were prepared by incorporating antidiabetic drug metformin hydrochloride (MTF) in grafted gum along with excipients. In vitro studies were performed on prepared tablet formulations showing release up to 8 h.


Assuntos
Acrilamida/síntese química , Química Farmacêutica/métodos , Sistemas de Liberação de Medicamentos/métodos , Micro-Ondas , Polissacarídeos Bacterianos/síntese química , Acrilamida/administração & dosagem , Animais , Feminino , Espectroscopia de Ressonância Magnética/métodos , Camundongos , Polissacarídeos Bacterianos/administração & dosagem , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Difração de Raios X
18.
Int J Biol Macromol ; 50(1): 198-206, 2012 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-22062120

RESUMO

Interpenetrating polymer network (IPN) hydrogel microspheres of sodium carboxymethyl cellulose (NaCMC) and poly(vinyl alcohol) (PVA) were prepared by water-in-oil (w/o) emulsion crosslinking method for oral controlled release delivery of a non-steroidal anti-inflammatory drug, diclofenac sodium (DS). The microspheres were prepared with various ratios of NaCMC to PVA, % drug loading and extent of crosslinking density at a fixed polymer weight. The prepared microspheres with loose and rigid surfaces were evidenced by scanning electron microscope (SEM). Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis confirmed the IPN formation. Differential scanning calorimetry (DSC) study was performed to understand the dispersion nature of drug after encapsulation. The in vitro drug release study was extensively evaluated depending on the process variables in both acid and alkaline media. All the formulations exhibited satisfactory physicochemical and in vitro release characteristics. Release data indicated a non-Fickian trend of drug release from the formulations. Based on the results of this study suggest that DS loaded IPN microspheres were suitable for oral controlled release application.


Assuntos
Preparações de Ação Retardada/química , Hidrogéis/química , Microesferas , Polímeros/química , Administração Oral , Anti-Inflamatórios não Esteroides/farmacologia , Varredura Diferencial de Calorimetria/métodos , Carboximetilcelulose Sódica/química , Química Farmacêutica/métodos , Diclofenaco/farmacologia , Cinética , Microscopia Eletrônica de Varredura/métodos , Modelos Químicos , Tamanho da Partícula , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Difração de Raios X
19.
Acta Pharm ; 61(3): 257-70, 2011 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-21945905

RESUMO

In this study, xanthan gum-facilitated ethyl cellulose microsponges were prepared by the double emulsification technique and subsequently dispersed in a carbopol gel base for controlled delivery of diclofenac sodium to the skin. Scanning electron microscopy revealed the porous, spherical nature of the microsponges. Increase in the drug/polymer ratio (0.4:1, 0.6:1, 0.8:1, m/m) increased their yield (79.1-88.5%), drug entrapment efficiency (50.0-64.1%), and mean particle diameter (181-255 µm). Compared to the microsponges with high drug/polymer ratio (0.8:1, m/m), the flux of entrapped drug through excised rat skin decreased by 19.9% and 17.0%, respectively, for the microsponges prepared at low and intermediate drug/polymer ratios. When an equivalent amount of pure drug (not entrapped into microsponges) was dispersed into the gel base and the flux was compared, the microsponges (drug/polymer ratio 0.8:1, m/m) were found to reduce the flux by 33.3%. Whether the drug was dispersed either in un-entrapped or entrapped form into the gel base, the drug permeation through rat skin followed Higuchi's diffusion kinetic model. The microsponges prepared at the lowest drug/polymer ratio exhibited a comparatively slower drug permeation profile and were hence considered most suitable for controlled drug delivery application. FTIR spectroscopy and DSC analyses indicated the chemically stable, amorphous nature of the drug in these microsponges. The gel containing these optimized microsponges was comparable to that of a commercial gel formulation and did not show serious dermal reactions. Hence, the microsponge system obtained at the lowest drug/polymer ratio could be useful for controlled release of diclofenac sodium to the skin.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Celulose/análogos & derivados , Preparações de Ação Retardada , Diclofenaco/farmacologia , Sistemas de Liberação de Medicamentos , Polissacarídeos Bacterianos/química , Administração Tópica , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/farmacocinética , Celulose/química , Diclofenaco/administração & dosagem , Diclofenaco/química , Diclofenaco/farmacocinética , Composição de Medicamentos , Avaliação Pré-Clínica de Medicamentos , Emulsificantes , Emulsões , Excipientes/química , Géis , Masculino , Tamanho da Partícula , Polímeros , Porosidade , Ratos , Ratos Wistar , Pele/efeitos dos fármacos , Absorção Cutânea , Viscosidade
20.
Drug Deliv ; 17(5): 288-300, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20350054

RESUMO

In this study, carboxymethyl derivative of locust bean gum was prepared, characterized, and its gelling ability with different concentrations (1-5% w/v) of aluminum chloride (AlCl(3)) was utilized for the development of glipizide-loaded beads in a completely aqueous environment. The beads were spherical when observed under a scanning electron microscope. Increase in gelling ion concentration decreased the drug entrapment efficiency from 97.68% to 95.14%. The beads swelled more slowly in pH 1.2 KCl-HCl buffer and exhibited a slower drug release pattern than that observed in pH 7.4 phosphate buffer. Irrespective of the dissolution media, the drug release became slower at higher AlCl(3) concentration. The drug release in alkaline medium was found to be controlled by a combination of diffusion as well as polymer relaxation phenomena. Comparing the release profiles, it was observed that the beads treated with 5% AlCl(3) provided slower drug release up to 10 h in alkaline medium without any sign of disintegration and, thus, this formulation was selected for further studies. Fourier transform infrared (FTIR) spectroscopy indicated the stable nature of the drug in the beads. Differential scanning calorimetry and X-ray diffraction analysis showed that most of the drug remained in amorphous state in the beads. Stability study indicated no statistical significant difference in drug entrapment efficiency of the beads. In vivo activity of the beads was tested and a prolonged hypoglycemic effect was achieved. Hence, carboxymethyl locust bean beads could be a potential carrier for controlled oral delivery of glipizide.


Assuntos
Sistemas de Liberação de Medicamentos , Galactanos/química , Glipizida/administração & dosagem , Hipoglicemiantes/administração & dosagem , Mananas/química , Gomas Vegetais/química , Administração Oral , Cloreto de Alumínio , Compostos de Alumínio/química , Cloretos/química , Preparações de Ação Retardada , Portadores de Fármacos/química , Estabilidade de Medicamentos , Hidrogéis , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Varredura , Espectroscopia de Infravermelho com Transformada de Fourier , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA