Effect of pH on the solubility and release of furosemide from polyamidoamine (PAMAM) dendrimer complexes.

The complexation of the practically insoluble drug furosemide (acidic pK(a) 3.22) with lower generation PAMAM dendrimers showed a significant release dependence on the ionization state of the drug. UV and FTIR studies suggested that the drug was localized in the interior of the dendrimer.

Effect of polyamidoamine (PAMAM) dendrimers on the in vitro release of water-insoluble nifedipine from aqueous gels.

The objective of this study was to determine the effect of ethylenediamine core PAMAM dendrimers on the release of nifedipine suspended in aqueous gels and to correlate release to the increase in solubility afforded by the dendrimers. Drug release from aqueous 5% HPMC gels containing nifedipine (2% wt/vol) through 0.2-microm membranes was measured using Enhancer cells and 50% ethanolic solution as the receptor medium.

Comparison of the aqueous solubilization of practically insoluble niclosamide by polyamidoamine (PAMAM) dendrimers and cyclodextrins.

This study is the first report of the solubilization of niclosamide by cyclodextrin complexation or the interaction between the drug and polyamidoamine (PAMAM) dendrimers. Half generation dendrimers with more polar carboxylate surface functional groups did not increase the solubility of niclosamide. From the phase solubility studies, when the fold enhancement in solubility of niclosamide combined with full generation amine terminated PAMAM dendrimers was compared with that obtained when the drug was combined with beta- or hydroxypropyl-beta-cyclodextrin, the results showed that, except for G-0 dendrimer at pH 7, the solubility of niclosamide was significantly higher in the presence of the dendrimers.

The relationship between surface adsorption and the hydrolysis of amitraz in anionic surfactant solutions.

The adsorption of amitraz to various adsorbents was studied in terms of the amount and rate of adsorption and the effect that adsorption had on the stability of amitraz in an aqueous environment. Adsorption results showed that in terms of their ability to adsorb amitraz from solution the adsorbents tested in this study can be ordered as follows: coarse carbon > cation exchange resin > or = anion exchange resin > fine carbon. Amitraz was not adsorbed on sand and potassium oxihumate.

The effect of PAMAM dendrimer generation size and surface functional group on the aqueous solubility of nifedipine.

The aim of this study was to investigate the effect of low generation (G0-G3) ethylenediamine (EDA) core poly(amidoamine) (PAMAM) dendrimers on the aqueous solubility of nifedipine. The aqueous solubility of nifedipine was measured in the presence of dendrimers at 30 degrees C in Tris buffers at pH 4, 7, and 10 using the traditional rotary bottle method. Results showed that generation size, surface functional group and the pH of the aqueous media determined the aqueous solubility of nifedipine and that solubility profiles were of the Higuchi AL-type.