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1.
Curr Drug Deliv ; 9(6): 628-36, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22452405

RESUMO

In current research, chitosan was reacted with mono-chloroacetic acid under alkaline condition to prepare carboxymethyl chitosan (CMCTs). The degree of substitution (Ds) on prepared CMCTs was found to be 0.68. CMCTs was used as a potential carrier for pH specific delivery of nateglinide after crosslinked using glutaraldehyde in presence of nateglinide. The average molecular weight and degree of deacetylation (DD) of chitosan were found to be 3.5x104 Da and 84.6% respectively. High yield (82%) and loading of drug (75%) were found in the developed hydrogel formulations. pH responsive swelling behavior of prepared hydrogels was checked using different pH values (1.2, 6.8 and 7.4). The study indicated very less swelling at pH 1.2 (for first 2 h) and quick swelling at pH 6.8 (for next 3 h) followed by linear swelling at pH 7.4 (for next 7 h) with slight increase. In vitro release profile of hydrogels showed biphasic release pattern dependent on swelling behavior. The release pattern was found to be non-fickian diffusion kinetics at higher pH. FTIR, 1H-NMR, DSC and p-XRD studies were carried out to confirm the formation of CMCTs, drug entrapment and its possible interaction in formulations. These studies revealed that no chemical change was found in nateglinide during preparation of hydrogel formulations. Scanning Electron Microscopy (SEM) was used to study the surface morphology of prepared hydrogels before and after dissolution which revealed pores formation after dissolution.


Assuntos
Quitosana/análogos & derivados , Cicloexanos/química , Portadores de Fármacos/química , Hipoglicemiantes/química , Fenilalanina/análogos & derivados , Quitosana/química , Reagentes de Ligações Cruzadas/química , Glutaral/química , Hidrogel de Polietilenoglicol-Dimetacrilato , Concentração de Íons de Hidrogênio , Nateglinida , Fenilalanina/química
2.
Pharm Dev Technol ; 17(1): 55-65, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-20849351

RESUMO

The current study involves the development of oral bioadhesive hydrophilic matrices of repaglinide and the optimization of their in vitro drug release and ex vivo bioadhesion. A simplex lattice design was employed to systematically optimize the drug delivery containing two polymers and a filler. The proportions of polyethylene oxide (PEO), microcrystalline cellulose (MCC) and lactose were varied to be fitted in simplex lattice design. Mucoadhesion (M), drug release at 2 h (Q2) and drug release at 8 h (Q8) were taken as responses. Response surface plots were drawn and the optimum formulation was selected by desirability function. The criteria for optimized formulation were set for mucoadhesion as maximum, Q2 as 20% and Q8 as 80%. The formulations were also checked for their swelling index and showed good swelling characteristic. In vitro drug release study was carried out using simulated gastric fluid (SGF) pH 1.2. The experimental values of M, Q2 and Q8 for check point batch were found to be 0.211N, 21.87% and 80.86% respectively. The release profile indicated anomalous (non-Fickian) transport mechanism. The optimized formulation was further checked for its compatibility with other excipients by studying FTIR and DSC studies and they indicated the absence of any significant chemical interaction within drug and excipients.


Assuntos
Carbamatos/administração & dosagem , Sistemas de Liberação de Medicamentos , Desenho de Fármacos , Hipoglicemiantes/administração & dosagem , Piperidinas/administração & dosagem , Algoritmos , Análise de Variância , Varredura Diferencial de Calorimetria , Química Farmacêutica , Composição de Medicamentos , Cinética , Metilcelulose , Mucosa , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Comprimidos , Adesivos Teciduais
3.
Carbohydr Res ; 347(1): 76-82, 2012 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-22099382

RESUMO

In the present study, carboxymethyl chitosan was prepared from chitosan, crosslinked with glutaraldehyde and evaluated in vitro as a potential carrier for colon targeted drug delivery of ornidazole. Ornidazole was incorporated at the time of crosslinking of carboxymethyl chitosan. The chitosan was evaluated for its degree of deacetylation (DD) and average molecular weight; which were found to be 84.6% and 3.5×10(4) Da, respectively. The degree of substitution on prepared carboxymethyl chitosan was found to be 0.68. All hydrogel formulations showed more than 85% and 74% yield and drug loading, respectively. The swelling behaviour of prepared hydrogels checked in different pH values, 1.2, 6.8 and 7.4, indicated pH responsive swelling characteristic with very less swelling at pH 1.2 and quick swelling at pH 6.8 followed by linear swelling at pH 7.4 with slight increase. In vitro release profile was carried out at the same conditions as in swelling and drug release was found to be dependant on swelling of hydrogels and showed biphasic release pattern with non-fickian diffusion kinetics at higher pH. The carboxymethylation of chitosan, entrapment of drug and its interaction in prepared hydrogels were checked by FTIR, (1)H NMR, DSC and p-XRD studies, which confirmed formation of carboxymethyl chitosan from chitosan and absence of any significant chemical change in ornidazole after being entrapped in crosslinked hydrogel formulations. The surface morphology of formulation S6 checked before and after dissolution, revealed open channel like pores formation after dissolution.


Assuntos
Quitosana/análogos & derivados , Colo/metabolismo , Portadores de Fármacos/química , Portadores de Fármacos/síntese química , Hidrogéis/química , Hidrogéis/síntese química , Ornidazol/química , Varredura Diferencial de Calorimetria , Quitosana/química , Preparações de Ação Retardada , Concentração de Íons de Hidrogênio , Cinética , Espectroscopia de Ressonância Magnética , Microscopia Eletrônica de Varredura , Ornidazol/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
4.
Curr Drug Discov Technol ; 8(2): 126-35, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21513486

RESUMO

The aim of this study was to develop a pH-sensitive chitosan/polyvinyl pyrrolidone (PVP) based controlled drug release system for repaglinide. The hydrogels were synthesised by crosslinking chitosan and PVP blend with glutaraldehyde to form a semi-interpenetrating polymer network (semi-IPN). These semi-IPNs were studied for their content uniformity, swelling index (SI), mucoadhesion, wettability, in vitro release and their release kinetics. The hydrogels showed more than 95% loading of repaglinide. These hydrogels showed high swelling and mucoadhesion under acidic conditions. The swelling was found due to the protonation of a primary amino group on chitosan. In acidic condition chitosan was ionized, and adhesion occurred between the positively charged chitosan and the negatively charged mucus. In the physiological condition less swelling was noticed. In vitro release study revealed that formulation containing chitosan (2% w/v) and PVP (4% w/v) in the ratio of 14:6 w/w showed complete drug release after 12h. Release profile showed that all the formulations followed non-fickian diffusion mechanism (diffusion coupled with swelling). Fourier transform infrared (FTIR) spectroscopic analysis revealed proper crosslinking of polymer and formation of semi-IPN as well as presence of drug in the formulation. Differential scanning calorimetry (DSC) and powder x-ray diffraction (p-XRD) study revealed the presence of repaglinide in crystalline form in the formulations. The surface morphology of semi-IPN was studied before and after dissolution in simulated gastric fluid (SGF, pH 1.2) which indicated generation of open channel-like structure in hydrogel after dissolution. The results of study suggest that semi-IPNs of chitosan/PVP are potent candidates for delivery of repaglinide in acidic environment.


Assuntos
Carbamatos/química , Quitosana/química , Portadores de Fármacos , Hidrogéis , Hipoglicemiantes/química , Piperidinas/química , Povidona/química , Adesividade , Animais , Varredura Diferencial de Calorimetria , Química Farmacêutica , Reagentes de Ligações Cruzadas/química , Cristalografia por Raios X , Preparações de Ação Retardada , Difusão , Composição de Medicamentos , Suco Gástrico/química , Glutaral/química , Concentração de Íons de Hidrogênio , Cinética , Microscopia Eletrônica de Varredura , Difração de Pó , Ratos , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Tecnologia Farmacêutica/métodos , Molhabilidade
5.
Braz. arch. biol. technol ; 54(2): 293-300, Mar.-Apr. 2011. ilus, tab
Artigo em Inglês | LILACS | ID: lil-582393

RESUMO

In this work a different type of formulation, as disc, containing a selected mucoadhesive polymer, fillers, and binders were investigated for their potential as a mucoadhesive gastroretentive delivery system to deliver famotidine in the stomach. Various types of hydrophilic diluents were evaluated for their swelling and mucoadhesive property and one (polyvinylpyrrolidone, PVP) was selected to combine with the selected mucoadhesive polymer (polyethylene oxide, PEO). Discs with different ratios of PEO and PVP were prepared and evaluated for swelling, dissolution, and mucoadhesion. The swelling property of the discs increased as the concentration of PEO was increased and also did the mucoadhesion. These discs retained their integrity and adherence onto gastric mucosa for more than 10 h under in-vitro conditions. The PEO, in combination with PVP, yielded a non-disintegrating type mucoadhesive dosage form which was suitable for gastroretentive applications to achieve the desired release profile of the drug.

6.
Drug Dev Ind Pharm ; 37(10): 1160-9, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21417603

RESUMO

The aim of this study was to develop a pH-sensitive chitosan/polyvinyl pyrrolidone (PVP) based controlled drug release system for clarithromycin. The hydrogels were synthesized by cross-linking chitosan and PVP blend with glutaraldehyde to form a semi-interpenetrating polymer network (semi-IPN). These semi-IPNs were studied for their content uniformity, swelling index (SI), mucoadhesion, wettability, in vitro release and their release kinetics. The hydrogels showed more than 97% content of clarithromycin. These hydrogels showed high swelling and mucoadhesion under acidic conditions. The swelling may be due to the protonation of a primary amino group on chitosan. In acidic condition, chitosan would be ionized, and adhesion could have occurred between the positively charged chitosan and the negatively charged mucus. In the alkaline condition, less swelling and mucoadhesion was noticed. In vitro release study revealed that formulation containing chitosan (2% w/v) and PVP (4% w/v) in the ratio of 21:4 showed complete drug release after 12 h. Release profile showed that all the formulations followed non-Fickian diffusion mechanism. The cross-linking and compatibility of clarithromycin in the formulation was studied by Fourier transform infrared (FTIR) spectroscopic analysis, differential scanning calorimetry (DSC) and powder X-ray diffraction (p-XRD) study, which confirmed proper formation of semi-IPN and stability of clarithromycin in the formulations. The surface morphology of semi-IPN was studied before and after dissolution in simulated gastric fluid (SGF, pH 1.2) which revealed pores formation in membrane after dissolution. The results of study suggest that semi-IPNs of chitosan/PVP are potent candidates for delivery of clarithromycin in acidic environment.


Assuntos
Quitosana/química , Claritromicina/farmacocinética , Hidrogéis/química , Povidona/química , Antibacterianos/química , Varredura Diferencial de Calorimetria , Preparações de Ação Retardada , Humanos , Concentração de Íons de Hidrogênio , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Molhabilidade , Difração de Raios X
7.
Pharm Dev Technol ; 16(2): 146-51, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20100058

RESUMO

The aim of the present study was to prepare and evaluate microspheres of Eudragit containing an antiviral drug stavudine. Microspheres were prepared by O/O solvent evaporation method using acetone/liquid paraffin system. The prepared microspheres were characterized for their micromeretic properties and entrapment efficiency; as well by Fourier transformed infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray powder diffractometry (XRPD) and scanning electron microscopy (SEM) which revealed the crystalline nature of drug in a final state. The in vitro studies revealed the controlled release of drug from microspheres up to 12 h and the best fit release kinetics was achieved with a Higuchi plot and found to be diffusion controlled. The yields of preparation and entrapment efficiencies were very high with a larger particle size for all the formulations. Mean particle size, entrapment efficiency and production yield were highly influenced by the type of polymer and polymer concentration.


Assuntos
Fármacos Anti-HIV/administração & dosagem , Preparações de Ação Retardada/química , Microesferas , Ácidos Polimetacrílicos/química , Estavudina/administração & dosagem , Síndrome da Imunodeficiência Adquirida/tratamento farmacológico , Varredura Diferencial de Calorimetria , Humanos , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Espectroscopia de Infravermelho com Transformada de Fourier
8.
Acta Pharm ; 60(4): 455-65, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21169137

RESUMO

The purpose of the present study was to design muco-adhesive chitosan microspheres containing amoxicillin. Chitosan microspheres with a small particle size and good sphericity were prepared by a spray-drying method followed by chemical treatment with a chemical crosslinking agent (glutaraldehyde). Parameters affecting the crosslinking extent of the crosslinking time and the concentration of the crosslinker agent. Crosslinked spray-dried chitosan microspheres were analyzed for their morphological aspects, particle size, drug entrapment efficiency, swelling percent and in vitro drug release. Batch M4 with a drug polymer ratio of 1:2, dissolved in minimum concentration of acetic acid solution treated with glutaraldehyde, was found to be optimal giving controlled drug release for 10 h. It was found that both the increase of glutaraldehyde concentration and crosslinking duration decreased the swelling capacity of chitosan microspheres. This could be directly correlated to drug release from the microspheres.


Assuntos
Amoxicilina/química , Antibacterianos/química , Quitosana/química , Microesferas , Ácido Acético/química , Adesividade , Amoxicilina/análise , Amoxicilina/farmacologia , Antibacterianos/análise , Antibacterianos/farmacologia , Quitosana/análise , Quitosana/farmacologia , Reagentes de Ligações Cruzadas/química , Preparações de Ação Retardada , Dessecação , Composição de Medicamentos , Glutaral/química , Humanos , Tamanho da Partícula , Polímeros , Solubilidade , Viscosidade
9.
J Adv Pharm Technol Res ; 1(2): 180-9, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22247844

RESUMO

Furosemide, a weekly acidic, loop diuretic drug indicated for treatment of edema and hypertension having high permeability through stomach. It is practically insoluble in gastric fluid (0.006 mg/ mL) and having highly permeability through stomach but due to its solubility limitation it can't enter into systemic circulation. It was logically decided to design experiment, so as to achieve the set objectives. Attempt was made to prepare solid dispersion of furosemide with Poly ethylene glycol (PEG) 6000 containing microcrystalline cellulose (MCC) as adsorbent which would dissolve completely in less than 30 minutes (target selected by considering minimum gastric empting time). Microcrystalline cellulose converted sticky dispersion in to free flow powder hence increase surface area which responsible for dissolution improvement. Factorial design was applied to optimize formulation. Amount of poly ethylene glycol 6000 and microcrystalline cellulose were selected as an Independent variable while angle of repose and T(100%) were selected as dependent variable. Attempts for dissolution rate of furosemide improve bioavailability and consequently dose reduction would possible.

10.
Acta Pharm ; 59(3): 273-88, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19819824

RESUMO

The purpose of the present investigation was to produce a quick/slow biphasic delivery system for metoclopramide hydrochloride using the superdisintegrant Ac-di-sol for the fast release layer and hydroxypropyl methylcellulose K100M and Ucarflock 302 to modulate the release of the drug. A dual component tablet made up of a sustained release and an immediate release layer was prepared by direct compression. A 3(2) full factorial design was applied to systematically optimize the drug release profile of the sustained release layer. The results of the full factorial design indicate that a small amount of HPMC K100M and a large amount of Ucarflock 302 favor sustained release of the metoclopramide hydrochloride vaginal dual component system. The ex vivo residence time reveals that the formulation was retained for more than 10 h. The formulation gave an initial burst effect to provide the loading dose of the drug followed by sustained release for 12 h, thus solving the problem of repeated administration, especially in pregnancy.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Metoclopramida/administração & dosagem , Administração Intravaginal , Animais , Celulose/administração & dosagem , Celulose/farmacocinética , Força Compressiva , Preparações de Ação Retardada , Feminino , Derivados da Hipromelose , Metilcelulose/administração & dosagem , Metilcelulose/análogos & derivados , Metilcelulose/farmacocinética , Metoclopramida/farmacocinética , Coelhos
11.
J AOAC Int ; 92(1): 158-64, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19382574

RESUMO

Two simple and accurate methods for the determination of pitavastatin calcium (PIT) in tablet dosage forms were developed and validated using column liquid chromatography (LC) and UV spectrophotometry. The LC separation was achieved on a Phenomenex Luna C18 column (250 mm, 4.6 mm id, 5 microm) in the isocratic mode using acetonitrile-water-triethylamine (80 + 19.8 + 0.2, v/v/v), adjusted to pH 3.5 +/- 0.05 with orthophosphoric acid, as the mobile phase at a flow rate of 1.5 mL/min. The retention time was 5.70 min. Both the methods were performed at 238 nm, the wavelength of maximum absorbance of PIT in methanol. In the LC method, quantification was achieved with a photodiode array detector over the concentration range of 0.1-2.5 microg/mL with a mean recovery of 100.26 +/- 0.75%. In the UV method, quantification was achieved over the concentration range of 2-20 microg/mL with mean recovery of 99.65 +/- 1.24%. Both methods were validated, and the results were compared statistically. They were found to be simple, specific, accurate, and precise. The methods were successfully applied for the determination of PIT in tablet dosage form without any interference from common excipients.


Assuntos
Quinolinas/análise , Comprimidos/análise , Cromatografia Líquida/métodos , Formas de Dosagem , Concentração de Íons de Hidrogênio , Inibidores de Hidroximetilglutaril-CoA Redutases/análise , Inibidores de Hidroximetilglutaril-CoA Redutases/química , Cinética , Modelos Moleculares , Quinolinas/química , Reprodutibilidade dos Testes , Espectrofotometria Ultravioleta/métodos
12.
J Chromatogr Sci ; 46(4): 304-7, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18402720

RESUMO

This paper describes a validated high-performance thin-layer chromatography (HPTLC) method for simultaneous estimation of rabeprazole (RA) and domperidone (DO) in pure powder and in capsule formulations. An HPTLC method separation is achieved on an aluminum sheet of silica gel 60F(254) using ethyl acetate-methanol-benzene-acetonitrile (30:20:30:20 v/v) as mobile phase. Quantitation is achieved with UV detection at 287 nm over a concentration range of 400-1200 ng/spot and 600-1800 ng/spot with mean recovery of 99.82 +/- 0.74 and 99.43 +/- 0.68 for RA and DO, respectively, in the HPTLC method. This method is simple, precise, and sensitive, and it is applicable for the simultaneous determination of RA and DO in pure powder and in capsule formulation.


Assuntos
2-Piridinilmetilsulfinilbenzimidazóis/isolamento & purificação , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia em Camada Fina/métodos , Domperidona/isolamento & purificação , Cápsulas/química , Rabeprazol , Reprodutibilidade dos Testes , Incerteza
13.
J Chromatogr Sci ; 46(1): 10-4, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18218182

RESUMO

Simple, sensitive high-performance liquid chromatography (HPLC) and thin-layer chromatography (TLC) methods are developed for the quantitative estimation of rabeprazole and mosapride in their combined pharmaceutical dosage forms. In HPLC, rabeprazole and mosapride are chromatographed using 0.01M 6.5 pH ammonium acetate buffer-methanol-acetonitrile (40:20:40, v/v, pH 5.70+/-0.02) as the mobile phase at a flow rate of 1.0 mL/min. In TLC, the mobile phase is ethyl acetate-methanol-benzene (2:0.5:2.5, v/v). Both the drugs are scanned at 276 nm. The retention times of rabeprazole and mosapride are found to be 4.93+/-0.01 and 9.79+/-0.02, respectively. The Rf values of rabeprazole and mosapride are found to be 0.42+/-0.02 and 0.61+/-0.02, respectively. The linearities of rabeprazole and mosapride are in the range of 400-2000 ng/mL and 300-1500 ng/mL, respectively, for HPLC; in TLC, the linearities of rabeprazole and mosapride are in the range of 400-1200 ng/spot and 300-900 ng/spot, respectively. The limit of detection is found to be 97.7 ng/mL for rabeprazole and 97.6 ng/mL for mosapride in HPLC; in TLC the limit of detection is found to be 132.29 ng/spot for rabeprazole and 98.25 ng/spot for mosapride. The proposed methods can be applied to the determination of rabeprazole and mosapride in combined pharmaceutical products.


Assuntos
2-Piridinilmetilsulfinilbenzimidazóis/análise , Benzamidas/análise , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia em Camada Fina/métodos , Morfolinas/análise , Rabeprazol , Reprodutibilidade dos Testes
14.
J AOAC Int ; 90(5): 1272-7, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17955972

RESUMO

A liquid chromatographic (LC) method and a UV spectrophotometric method were developed and validated for quantitative determination of linezolid in tablets and injection. The isocratic LC analyses were performed on an RP18 column using a mobile phase composed of methanol-water-acetonitrile (40 + 40 + 20, v/v/v) at a flow rate of 1.0 mL/min. The UV spectrophotometric method was performed at 251 nm. The analytical methods were validated according to International Conference on Harmonization guidelines. The calibration graphs were linear (correlation coefficient > 0.999) in the studied concentration ranges of 0.1 to 10 microg/mL for LC and 2 to 16 microg/mL for UV spectrophotometry. The relative standard deviation values for intraday and interday precision studies were <2%, and the accuracy was >98% for both methods. The specificity of the LC method was proved using forced degradation. Statistical analysis showed no significant difference between the results obtained by the 2 methods. The proposed methods are precise and accurate and can be applied directly to the oral and parenteral pharmaceutical preparations of linezolid.


Assuntos
Acetamidas/análise , Anti-Infecciosos/análise , Química Farmacêutica/métodos , Cromatografia Líquida/métodos , Oxazolidinonas/análise , Espectrofotometria Ultravioleta/métodos , Acetamidas/química , Acetonitrilas/química , Administração Oral , Anti-Infecciosos/química , Calibragem , Técnicas de Química Analítica/métodos , Linezolida , Metanol/química , Modelos Químicos , Oxazolidinonas/química , Fotometria , Análise de Regressão , Reprodutibilidade dos Testes , Água/química
15.
AAPS PharmSciTech ; 8(2): Article 45, 2007 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-17622120

RESUMO

The purpose of this study was to develop formulations and systematically evaluate in vitro performances of buccoadhesive patches of propranolol hydrochloride using the hydrophobic polymer Eudragit L-100 as the base matrix. The hydrophilic polymers Carbopol 934 and polyvinyl pyrrolidone (PVP) K30 were incorporated into the Eudragit patches, to provide the patches with bioadhesive properties and to modify the rate of drug release. The patches, which were prepared by the solvent casting method, were smooth and elegant in appearance; were uniform in thickness, weight, and drug content; showed no visible cracks; and showed good folding endurance. A 3(2) full factorial design was employed to study the effect of independent variables like hydrophilic polymers Carbopol 934 and PVP K30, which significantly influenced characteristics like swelling index, ex vivo mucoadhesive strength, in vitro drug release, and ex vivo residence time. A stability study of optimized Eudragit patches was done in natural human saliva; it was found that both drug and buccal patches were stable in human saliva. It can be concluded that the present buccal formulation can be an ideal system to improve the bioavailability of the drug by avoiding hepatic first-pass metabolism.


Assuntos
Ácidos Polimetacrílicos/administração & dosagem , Propranolol/administração & dosagem , Acrilatos/administração & dosagem , Animais , Química Farmacêutica , Sistemas de Liberação de Medicamentos , Estabilidade de Medicamentos , Humanos , Mucosa Bucal , Povidona/administração & dosagem , Propranolol/química , Análise de Regressão , Ovinos , Solubilidade
16.
AAPS PharmSciTech ; 8(1): 22, 2007 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-17408221

RESUMO

The purpose of this research work was to establish mucoadhesive buccal devices of propranolol hydrochloride (PRH) in the forms of bilayered and multilayered tablets. The tablets were prepared using sodium carboxymethylcellulose (SCMC) and Carbopol-934 (CP) as bioadhesive polymers to impart mucoadhesion and ethyl cellulose (EC) to act as an impermeable backing layer. Buccal devices were evaluated by different parameters such as weight uniformity, content uniformity, thickness, hardness, surface pH, swelling index, ex vivo mucoadhesive strength, ex vivo mucoadhesion time, in vitro drug release, and in vitro drug permeation. As compared with bilayered tablets, multilayered tablets showed slow release rate of drug with improved ex vivo bioadhesive strength and enhanced ex vivo mucoadhesion time. The mechanism of drug release was found to be non-Fickian diffusion (value of n between 0.5 and 1.0) for both the buccal devices. The stability of drug in both the optimized buccal devices was tested for 6 hours in natural human saliva; both the buccal devices were found to be stable in natural human saliva. The present study concludes that mucoadhesive buccal devices of PRH can be a good way to bypass the extensive hepatic first-pass metabolism and to improve the bioavailability of PRH.


Assuntos
Materiais Revestidos Biocompatíveis/química , Preparações de Ação Retardada/química , Mucosa Bucal/química , Preparações Farmacêuticas/administração & dosagem , Preparações Farmacêuticas/química , Propranolol/química , Saliva/química , Comprimidos/química , Adesividade , Animais , Difusão , Humanos , Ovinos , Propriedades de Superfície
17.
J AOAC Int ; 90(1): 142-6, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17373444

RESUMO

This paper describes validated high-performance liquid chromatography (HPLC) and high-performance thin-layer chromatography (HPTLC) methods for the simultaneous estimation of pantoprazole (PANT) and domperidone (DOM) in pure powder and capsule formulations. The HPLC separation was achieved on a Phenomenex C18 column (250 mm id, 4.6 mm, 5 pm) using 0.01 M, 6.5 pH ammonium acetate buffer-methanol-acetonitrile (30 + 40 + 30, v/v/v, pH 7.20) as the mobile phase at a flow rate of 1.0 mL/min at ambient temperature. The HPTLC separation was achieved on an aluminum-backed layer of silica gel 60F254 using ethyl acetate-methanol (60 + 40, v/v) as the mobile phase. Quantification was achieved with ultraviolet (UV) detection at 287 nm over the concentration range 400-4000 and 300-3000 ng/mL with mean recovery of 99.35+/-0.80 and 99.08+/-0.57% for PANT and DOM, respectively (HPLC method). Quantification was achieved with UV detection at 287 nm over the concentration range 80-240 and 60-180 ng/spot with mean recovery of 98.40+/-0.67 and 98.75+/-0.71% for PANT and DOM, respectively (HPTLC method). These methods are simple, precise, and sensitive, and they are applicable for the simultaneous determination of PANT and DOM in pure powder and capsule formulations.


Assuntos
2-Piridinilmetilsulfinilbenzimidazóis/análise , Domperidona/análise , Pós/química , 2-Piridinilmetilsulfinilbenzimidazóis/isolamento & purificação , Antiulcerosos/análise , Antiulcerosos/isolamento & purificação , Química Farmacêutica , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida/métodos , Cromatografia em Camada Fina/métodos , Domperidona/isolamento & purificação , Pantoprazol , Preparações Farmacêuticas/química , Sensibilidade e Especificidade
18.
Curr Drug Deliv ; 4(1): 41-50, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17269916

RESUMO

The purpose of this research was to formulate and systematically evaluate in vitro and in vivo performances of mucoadhesive amoxicillin microspheres for the potential use of treating gastric and duodenal ulcers, which were associated with Helicobacter pylori. Amoxicillin mucoadhesive microspheres containing chitosan as mucoadhesive polymer were prepared by simple emulsification phase separation technique using glutaraldehyde as a cross-linking agent. Results of preliminary trials indicate that volume of cross-linking agent, time for cross-linking, polymer-to-drug ratio, and speed of rotation affected characteristics of microspheres. Microspheres were discrete, spherical, free flowing and also showed high percentage drug entrapment efficiency. In vitro mucoadhesive test showed that amoxicillin mucoadhesive microspheres adhered more strongly to gastric mucous layer and could retain in gastrointestinal tract for an extended period of time. A 3(2) full factorial design was employed to study the effect of independent variables, polymer-to-drug ratio (X(1)), and stirring speed (X(2)) on dependent variables i.e. percentage mucoadhesion, t(80), drug entrapment efficiency, particle size and swelling index. The best batch exhibited a high drug entrapment efficiency of 70 % and a swelling index of 1.39; percentage mucoadhesion after 1 h was 79 %. The drug release was also sustained for more than 12 h. The polymer-to-drug ratio had a more significant effect on the dependent variables. The morphological characteristics of the mucoadhesive microspheres were studied using scanning electron microscopy. In vitro release test showed that amoxicillin released slightly faster in pH 1.0 hydrochloric acid than in pH 7.8 phosphate buffer. In vivo H. pylori clearance tests were also carried out by administering amoxicillin mucoadhesive microspheres and powder, to H. pylori infectious Wistar rats under fed conditions at single dose or multiple dose(s) in oral administration. The results showed that amoxicillin mucoadhesive microspheres had a better clearance effect than amoxicillin powder. In conclusion, the prolonged gastrointestinal residence time and enhanced amoxicillin stability resulting from the mucoadhesive microspheres of amoxicillin might make contribution complete eradication of H. pylori.


Assuntos
Amoxicilina/uso terapêutico , Infecções por Helicobacter/tratamento farmacológico , Helicobacter pylori/efeitos dos fármacos , Microesferas , Estômago/efeitos dos fármacos , Ácido Acético/química , Adesividade , Amoxicilina/química , Amoxicilina/farmacocinética , Animais , Antibacterianos/administração & dosagem , Antibacterianos/farmacocinética , Antibacterianos/uso terapêutico , Disponibilidade Biológica , Quitosana/química , Ácido Dioctil Sulfossuccínico/química , Sistemas de Liberação de Medicamentos/métodos , Sistemas de Liberação de Medicamentos/normas , Glutaral/química , Infecções por Helicobacter/microbiologia , Helicobacter pylori/crescimento & desenvolvimento , Microscopia Eletrônica de Varredura , Óleo Mineral/química , Tamanho da Partícula , Pós , Ratos , Reprodutibilidade dos Testes , Estômago/microbiologia
19.
Acta Pharm ; 57(1): 61-72, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19839407

RESUMO

Mucoadhesive buccal patches containing propranolol hydrochloride were prepared using the solvent casting method. Chitosan was used as bioadhesive polymer and different ratios of chitosan to PVP K-30 were used. The patches were evaluated for their physical characteristics like mass variation, drug content uniformity, folding endurance, ex vivo mucoadhesion strength, ex vivo mucoadhesion time, surface pH, in vitro drug release, and in vitro buccal permeation study. Patches exhibited controlled release for a period of 7 h. The mechanism of drug release was found to be non-Fickian diffusion and followed the first-order kinetics. Incorporation of PVP K-30 generally enhanced the release rate. Swelling index was proportional to the concentration of PVP K-30. Optimized patches (F4) showed satisfactory bioadhesive strength of 9.6 +/- 2.0 g, and ex vivo mucoadhesion time of 272 minutes. The surface pH of all patches was between 5.7 and 6.3 and hence patches should not cause irritation in the buccal cavity. Patches containing 10 mg of drug had higher bioadhesive strength with sustained drug release as compared to patches containing 20 mg of drug. Good correlation was observed between the in vitro drug release and in vitro drug permeation with a correlation coefficient of 0.9364. Stability study of optimized patches was done in human saliva and it was found that both drug and buccal patches were stable.


Assuntos
Adesivos/química , Antagonistas Adrenérgicos beta/administração & dosagem , Quitosana/química , Mucosa Bucal , Propranolol/administração & dosagem , Adesividade , Adolescente , Adulto , Algoritmos , Animais , Bochecha , Desenho de Fármacos , Feminino , Humanos , Concentração de Íons de Hidrogênio , Técnicas In Vitro , Masculino , Pessoa de Meia-Idade , Excipientes Farmacêuticos , Povidona , Saliva/química , Ovinos , Adulto Jovem
20.
AAPS PharmSciTech ; 6(1): E49-55, 2005 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-16353963

RESUMO

The purpose of this research was to formulate and systematically evaluate in vitro and in vivo performances of mucoadhesive microspheres of glipizide. Glipizide microspheres containing chitosan were prepared by simple emulsification phase separation technique using glutaraldehyde as a cross-linking agent. Results of preliminary trials indicate that volume of cross-linking agent, time for cross-linking, polymer-to-drug ratio, and speed of rotation affected characteristics of microspheres. Microspheres were discrete, spherical, and free flowing. The microspheres exhibited good mucoadhesive property in the in vitro wash-off test and also showed a high percentage drug entrapment efficiency. A 3(2) full factorial design was employed to study the effect of independent variables, polymer-to-drug ratio (X(1) ), and stirring speed (X(2) ) on dependent variables percentage mucoadhesion, t(80), drug entrapment efficiency, and swelling index. The best batch exhibited a high drug entrapment efficiency of 75% and a swelling index of 1.42; percentage mucoadhesion after 1 hour was 78%. The drug release was also sustained for more than 12 hours. The polymer-to-drug ratio had a more significant effect on the dependent variables. In vivo testing of the mucoadhesive microspheres to albino Wistar rats demonstrated significant hypoglycemic effect of glipizide.


Assuntos
Glipizida/química , Glipizida/farmacologia , Microesferas , Adesivos Teciduais/química , Adesivos Teciduais/farmacologia , Animais , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Química Farmacêutica , Avaliação Pré-Clínica de Medicamentos/métodos , Ratos , Ratos Wistar
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