Este artigo analisa a evolução da estrutura do segmento de medicamentos de marca e genéricos no Brasil a partir de 1997. Após a entrada dos medicamentos genéricos, constatou-se que não houve diminuição significativa da concentração na indústria farmacêutica brasileira, porém, o mesmo não ocorreu em nível mundial, verificando-se um aumento da concentração a partir de 2001, impulsionado pelo expressivo processo de fusões e aquisições nos últimos anos da década de 1990. Em relação ao turnover, notou-se que este foi muito baixo para o grupo das maiores empresas em ambos os segmentos de medicamentos. Entretanto, observa-se um elevado turnover com a entrada dos genéricos, mostrando o fortalecimento da indústria nacional. Verifica-se que o processo de fusões e aquisições entre empresas nacionais é pouco significativo, o que pode ser uma alternativa para as pequenas empresas farmacêuticas aumentarem a sua participação no mercado brasileiro.
This work presents the results of the physical characterization of palygorskite and its adsorptive behaviour for three solvatochromic dyes (Nile blue chloride (NBC), methylene blue (MTB) and dithizone (DTZ)). Adsorption isotherms were used to determine the maximum adsorption of the solvatochromic dyes on the palygorskite. The characterization of palygorskite was carried out via mineralogical and chemical analysis with X-ray diffraction, X-ray fluorescence, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy, surface-charge measurement (ζ-potential), thermogravimetric analysis, textural analysis and cation-exchange capacity analysis. The material consists of palygorskite and quartz and its chemistry is dominated by SiO2, MgO and Fe2O3. The specific surface area and cation-exchange capacity of the palygorskite are 142 m2 g–1 and 41 cmol(+) kg–1, respectively. The SEM and TEM analyses showed a fibrous structure with fibres 20–100 nm long. The thermogravimetric analysis showed three endothermic events at 57.3°C, 171.8°C and 439.6°C. The adsorption capacities of the palygorskite for NBC (basic pH), MTB (basic pH) and DTZ (neutral pH) were 0.082, 0.013 and 0.102 g g–1, respectively. The adsorptions of NBC and MTB were fitted with the Langmuir isotherm model and the adsorption of DTZ was fitted with the Sips model.
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