caa a22 4500 477126162 CHVBK 20180405111650.0 cr unu---uuuuu 170330e19970901xx s 000 0 eng 10.1023/A:1012146621821 doi (NATIONALLICENCE)springer-10.1023/A:1012146621821 Study of Hygroscopic Properties of Aqueous Mixtures of Disodium Fluorescein and Sodium Chloride Using an Electrodynamic Balance [Elektronische Daten] [Chak Chan, Chin Kwok, Albert Chow] Purpose. The purposes of this study are: a) to demonstrate the use of an Electrodynamic Balance (EDB) to investigate the hygroscopic properties of pharmaceutical aerosols; and b) to evaluate the applicability of the Zdanovskii-Stokes-Robinson model (ZSR) in the associated data analysis with multicomponent pharmaceutical aerosols. Methods. The compositional dependence of the water activity of two model materials commonly employed in the study of pharmaceutical aerosols, namely, NaCl and Disodium Fluorescein(DF), was investigated using an EDB. The water contents of single levitated droplets of NaCl and DF and their mixtures at mass ratios of 1:3, 1:1, 3:1, and 6:1 from dilute concentration to high supersaturation were determined as a function of relative humidity (RH). Results. At decreasing ambient RH, supersaturated aqueous NaCl droplets lose water and crystallize to form dry solid particles at an RH of ~50%. Aqueous DF droplet continues to lose water until it reaches a final state containing about 20% by mass of residual water. Mixed solutions of DF and NaCl crystallize at an RH of ~50% and then continue to lose water at lower RHs. The resulting 'dried' particle still contains water whose amount depends on the mass ratios of DF and NaCl in the mixture. Good prediction of water activity of the DF-NaCl mixture can be achieved with the ZSR model. Collection of a full set of water activity-composition data at each mass ratio of DF-NaCl requires only a few hours. Conclusions. The EDB, together with the application of the ZSR model in data treatment, appears to be a valuable tool for studying the hygroscopic properties of pharmaceutical aerosols. Plenum Publishing Corporation, 1997 electrodynamic balance nationallicence single particle levitation nationallicence water activity nationallicence hygroscopic aerosol growth nationallicence disodium fluorescein nationallicence sodium chloride nationallicence Chan Chak Department of Chemical Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong aut Kwok Chin Department of Chemical Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong aut Chow Albert Department of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong aut Pharmaceutical Research Kluwer Academic Publishers-Plenum Publishers 14/9(1997-09-01), 1171-1175 0724-8741 14:9<1171 1997 14 11095 https://doi.org/10.1023/A:1012146621821 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1012146621821 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Chan Chak Department of Chemical Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong aut NATIONALLICENCE 700 1- Kwok Chin Department of Chemical Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong aut NATIONALLICENCE 700 1- Chow Albert Department of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong aut NATIONALLICENCE 773 0- Pharmaceutical Research Kluwer Academic Publishers-Plenum Publishers 14/9(1997-09-01), 1171-1175 0724-8741 14:9<1171 1997 14 11095 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer