A high dosage of albendazole (ABZ) is required for treating systemic helminthe infections because of its low solubility. Aiming at increasing ABZ solubility, complexation with beta-cyclodextrin (β-CD) using aqueous and acetic acid solutions as ABZ solubilizer was studied. In aqueous β-CD, complexation increased solubility 53.4 times, giving a complex equilibrium constant of 1266 L mol-1 with a maximum ABZ concentration of 276 µmol L-1 for 16.3 mmol L-1 β-CD. For complexation in 1.05 mol L-1 acetic acid, UV absorbance spectra and ¹H-NMR analysis confirmed complex formation. The UV absorbance of ABZ/acid acetic/β-CD solutions was modeled by the formation of two complexes with molar ratios 1:1 and 1:2 ABZ:β-CD. When neutralized with NaOH these solutions did not form precipitates only for the ABZ:β-CD molar ratios of 1:8 and 1:10, showing that ABZ solubility could be increased 306 times. Results show that high β-CD molar ratios hold ABZ in solution by complexation enhanced by the acetate anion.

Estudou-se neste trabalho, a cinética de adsorção e o equilíbrio de adsorção do azul de metileno (AM) em lignina fórmica reticulada (LFR) obtida do bagaço de cana de açúcar. O processo de adsorção é dependente do pH, temperatura e força iônica (µ) e obedece ao modelo de Langmuir. Algumas condições como a alta capacidade e velocidade de adsorção foram determinadas. Observouse rápida adsorção (12 horas) e alta capacidade de adsorção (34,20 mg.g-1) em pH = 5,8 (tampão aceta-to de sódio-ácido acético), 50ºC e 0,1 de força iônica. Para alcançar o equilíbrio de adsorção, o sistema foi termostatizado com tempos de 1 a 10 dias, com agitação ocasional.

The adsorption kinetics and equilibrium of methylene blue (MB) onto reticulated formic lignin (RFL) from sugar cane bagasse was studied. The adsorption process is pH, temperature and ionic strength (µ) dependent and obeys the Langmuir model. Conditions for higher adsorption rate and capacity were determined. The faster adsorption (12 hours) and higher adsorption capacity (34.20 mg.g-1) were observed at pH = 5.8 (acetic acid-sodium acetate aqueous buffer), 50 ºC and 0.1 ionic strength. Under temperature (50 ºC) control and occasional mechanical stirring it took from 1 to 10 days to reach the equilibrium.