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1.
Drug Dev Ind Pharm ; 25(3): 297-305, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10071822

RESUMO

The compression ability and dissolution rate of ibuprofen are poor. There are many processes to optimize these properties through adapted formulations. However, it would be more satisfactory to obtain directly during the crystallization step crystalline particles that can be directly compressed and quickly dissolved. This was the aim of this work. Ibuprofen spherical agglomerates were obtained using a very simple method based on the difference of solubility of ibuprofen in ethanol and in water. By cooling down an ibuprofen-saturated solution in an ethanol/water 50/50 mixture from 60 degrees C to room temperature under stirring, a phase separation occurs. Ibuprofen crystallizes in separated water droplets. After separation by sieving and drying, spherical agglomerates were obtained. A study of the physical properties of ibuprofen agglomerates was carried out using electron scanning microscopy and X-ray powder diffraction. The compression ability was tested using an instrumented tablet machine, and the dissolution rate was measured using continuous flow cells. An improvement in compression and dissolution properties of the spherical agglomerates produced was observed. The process of crystallization in a separated dispersed phase could be envisaged each time a drug exhibits opposite solubilities in two miscible solvents.


Assuntos
Anti-Inflamatórios não Esteroides/química , Ibuprofeno/química , Anti-Inflamatórios não Esteroides/administração & dosagem , Cristalização , Etanol , Ibuprofeno/administração & dosagem , Microscopia Eletrônica de Varredura , Microesferas , Solubilidade , Solventes , Temperatura , Água , Difração de Raios X
2.
Pharm Res ; 15(7): 1122-30, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9688070

RESUMO

PURPOSE: Orthorhombic crystals of paracetamol exhibit good technological properties during compression. The purpose of this study was to investigate the compression behavior of this substance and to compare it to that of monoclinic paracetamol. From the crystal structure, it could be hypothesized that sliding planes are present in the orthorhombic form, and could be responsible for an increase in crystal plasticity. METHODS: Compression of pure orthorhombic or monoclinic paracetamol tablets was carried out on a fully instrumented single punch machine. Data was used to establish Heckel's profiles. Images of compressed crystals were obtained by scanning electron microscopy. RESULTS: Tabletability of the orthorhombic crystals was far better than that of the monoclinic ones, and capping was not observed even at high compression pressure. Compared to the monoclinic form, orthorhombic paracetamol exhibited greater fragmentation at low pressure, increased plastic deformation at higher pressure, and lower elastic recovery during decompression. Plastic behavior was confirmed by SEM - micrographs showing that crystals folded under pressure. A compactibility study showed that the nature of interparticle bonds was similar for both polymorphs, the number of bonds being greater for orthorhombic paracetamol. CONCLUSIONS: Unlike the monoclinic form, orthorhombic paracetamol is suitable for the direct compression process. The crystalline structure accounts for its better compression behavior, because of the presence of sliding planes.


Assuntos
Acetaminofen/química , Analgésicos não Narcóticos/química , Química Farmacêutica , Acetaminofen/administração & dosagem , Analgésicos não Narcóticos/administração & dosagem , Fenômenos Químicos , Físico-Química , Força Compressiva , Elasticidade , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Pós , Comprimidos , Resistência à Tração
10.
Int J Health Serv ; 8(3): 509-18, 1978.
Artigo em Inglês | MEDLINE | ID: mdl-681048

RESUMO

For the 1978 legislative elections, all French political parties have, for the first time, a relatively detailed health policy. The right-wing parties of the present government concentrate on the reduction of medical expenditure and the maintenance of the free enterprise tradition of French medicine. The left-wing parties concentrate more on the development of public health institutions and suggest nationalization of the pharmaceutical industry. Within the Left, there is, however, a difference of emphasis: the Socialists propose the setting up of medicosocial centers and abolition of the fee-for-service system; the Communists concentrate rather on industrial health and believe that an improved health service can only come from changes in overall social economic policy. None of these policies is particularly adventurous but their mere existence shows that health is now a major political preoccupation in France. Some of these policies are mainly concerned with individual and public welfare and others with the necessity of maintaining a certain social order. The debate surrounding health policy usually turns around these two issues.


Assuntos
Atenção à Saúde/legislação & jurisprudência , Governo , Política Pública/legislação & jurisprudência , Comunismo , Atenção à Saúde/economia , França , Política , Previdência Social , Socialismo
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