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1.
Eur J Pharm Sci ; 23(4-5): 355-62, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15567288

RESUMO

A simple linear regression method was developed and statistically validated for the direct and non-destructive quantitative analysis--without sample preparation--of the active pharmaceutical ingredient (API) medroxyprogesterone acetate (MPA) in an aqueous pharmaceutical suspension (150 mg in 1.0 ml) using FT-Raman spectroscopy. The linear regression was modelled by plotting the highest peak intensity of the vector normalized spectral band between 1630 and 1590 cm-1 against different MPA standard suspension concentrations. At this band, no spectral interferences from additives in the suspension are observed. The validated model was used for the quantification of a commercial suspension (150 mg in 1.0 ml) of the commercialized preparations. The same standards and samples were used, respectively, for the development and validation of a simple linear regression model and for the quantitative determination by means of HPLC-with sample preparation-as described for the related substances of MPA in the Ph. Eur. IV. The quantification results obtained by the FT-Raman method corresponded with the claimed label concentration (150.01+/-0.96 mg/ml (n=6)). Applying the HPLC method, however, a systematic error was observed (157.77+/-0.94 mg/ml (n=6)). The direct FT-Raman method hence appears the most reliable for the quantification of the MPA component in suspension, compared to the HPLC method that requires sample preparation. The latter method provides a systematic error because the exact volume or density of a suspension sample is unknown. A precise isolation of fixed volumes from a suspension is rather unfeasible because of the continuous sagging of the suspended particles and their sticking to the used materials in the isolation process.


Assuntos
Acetato de Medroxiprogesterona/análise , Acetato de Medroxiprogesterona/normas , Análise Espectral Raman/métodos , Tecnologia Farmacêutica/métodos , Cromatografia Líquida de Alta Pressão , Modelos Químicos , Soluções Farmacêuticas/análise , Soluções Farmacêuticas/normas , Análise Espectral Raman/normas
2.
Eur J Pharm Sci ; 21(4): 479-85, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-14998578

RESUMO

FT-Raman spectroscopy (in combination with a fibre optic probe) was evaluated as an in-line tool to monitor a blending process of diltiazem hydrochloride pellets and paraffinic wax beads. The mean square of differences (MSD) between two consecutive spectra was used to identify the time required to obtain a homogeneous mixture. A traditional end-sampling thief probe was used to collect samples, followed by HPLC analysis to verify the Raman data. Large variations were seen in the FT-Raman spectra logged during the initial minutes of the blending process using a binary mixture (ratio: 50/50, w/w) of diltiazem pellets and paraffinic wax beads (particle size: 800-1200 microm). The MSD-profiles showed that a homogeneous mixture was obtained after about 15 min blending. HPLC analysis confirmed these observations. The Raman data showed that the mixing kinetics depended on the particle size of the material and on the mixing speed. The results of this study proved that FT-Raman spectroscopy can be successfully implemented as an in-line monitoring tool for blending processes.


Assuntos
Análise de Fourier , Análise Espectral Raman/métodos , Tecnologia Farmacêutica/métodos , Tecnologia Farmacêutica/instrumentação
3.
Eur J Pharm Sci ; 17(3): 145-51, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12393142

RESUMO

Placebo particles were mixed with film-coated diltiazem pellets to evaluate them as cushioning agents during tabletting in order to protect the film coat from damage. The cushioning properties of alpha-lactose monohydrate granules, microcrystalline cellulose pellets and wax/starch beads were evaluated by comparing the dissolution profile of the coated pellets before and after compression (compression force 10 kN). Only the tablet formulations containing wax/starch beads provided protection to the film coat. However, the dissolution rate of tablets formulated with waxy maltodextrin/paraffinic wax placebo beads was too slow as the tablets did not disintegrate. Adding 50% (w/w) drum-dried corn starch/Explotab/paraffinic wax beads to the formulation was the optimal amount of cushioning beads to provide sufficient protection for the film coat and yield disintegrating tablets. Using a compression simulator, the effect of precompression force and compression time on the dissolution rate was found to be insignificant. The diametral crushing strength of tablets containing 50% (w/w) drum-dried corn starch/Explotab/paraffinic wax beads was about 25.0 N (+/-0.3 N), with a friability of 0.4% (+/-0.04%). This study demonstrates that adding deformable wax pellets minimizes the damage to film-coated pellets during compression.


Assuntos
Diltiazem/química , Ácidos Polimetacrílicos/química , Ceras/química , Força Compressiva , Diltiazem/farmacocinética , Ácidos Polimetacrílicos/farmacocinética , Solubilidade , Comprimidos com Revestimento Entérico , Ceras/farmacocinética
4.
Int J Pharm ; 240(1-2): 79-84, 2002 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-12062503

RESUMO

The aim of this study was to evaluate the in-vivo behaviour of matrix pellets formulated with nanocrystalline ketoprofen after oral administration to dogs. No significant differences in AUC-values were seen between pellet formulations containing nanocrystalline or microcrystalline ketoprofen and a commercial ketoprofen formulation (reference: Rofenid 200 Long Acting). C(max) of the formulations containing nano- or microcrystalline ketoprofen was significantly higher compared to reference, whereas t(max) was significantly lower. The in-vivo burst release observed for the spray dried nanocrystalline ketoprofen matrix pellets was reduced following compression of the pellets in combination with placebo wax/starch pellets. These matrix tablets sustained the ketoprofen plasma concentrations during 5.6 and 5.4 h for formulations containing nano- and microcrystalline ketoprofen, respectively.


Assuntos
Anti-Inflamatórios não Esteroides/farmacocinética , Cetoprofeno/farmacocinética , Nanotecnologia , Administração Oral , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/sangue , Disponibilidade Biológica , Cromatografia Líquida de Alta Pressão , Cães , Feminino , Cetoprofeno/administração & dosagem , Cetoprofeno/sangue , Masculino , Tamanho da Partícula , Solubilidade , Comprimidos com Revestimento Entérico , Fatores de Tempo
5.
Int J Pharm ; 219(1-2): 81-7, 2001 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-11337168

RESUMO

A controlled release pellet formulation using a NanoCrystal colloidal dispersion of ketoprofen was developed. In order to be able to process the aqueous NanoCrystal colloidal dispersion into a hydrophobic solid dosage form a spray drying procedure was used. The in vitro dissolution profiles of wax based pellets loaded with nanocrystalline ketoprofen are compared with the profiles of wax based pellets loaded with microcrystalline ketoprofen and of a commercial sustained release ketoprofen formulation. Pellets were produced using a melt pelletisation technique. All pellet formulations were composed of a mixture of microcrystalline wax and starch derivatives. The starch derivatives used were waxy maltodextrin and drum dried corn starch. Varying the concentration of drum dried corn starch increased the release rate of ketoprofen but the ketoprofen recovery remained problematic. To increase the dissolution yield surfactants were utilised. The surfactants were either added during the production process of the NanoCrystal colloidal dispersion (sodium laurylsulphate) or during the pellet manufacturing process (Cremophor RH 40). Both methods resulted in a sustained but complete release of nanocrystalline ketoprofen from the matrix pellet formulations.


Assuntos
Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/farmacocinética , Cetoprofeno/administração & dosagem , Cetoprofeno/farmacocinética , Administração Oral , Cristalização , Excipientes , Liofilização , Concentração de Íons de Hidrogênio , Cetoprofeno/química , Microscopia Eletrônica de Varredura , Porosidade , Solubilidade , Amido , Propriedades de Superfície , Comprimidos com Revestimento Entérico , Ceras , Difração de Raios X
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