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The change in surface energy of cefditoren pivoxil powder as a consequence of changes in crystallinity (caused by milling duration) was studied using inverse gas chromatography (IGC) under dry conditions. The surface of the powder became more basic with decreasing crystallinity. It was suggested by considering the results of IR spectra that this resulted(More)
The purpose of this work was to characterize theophylline (THF) cocrystals prepared by spray drying in terms of the physicochemical properties and inhalation performance when aerosolized from a dry powder inhaler. Cocrystals of theophylline with urea (THF-URE), saccharin (THF-SAC) and nicotinamide (THF-NIC) were prepared by spray drying. Milled THF and(More)
Seventy one patients with benign oesophageal strictures were randomised to receive balloon or bougie dilatation. Sixty five patients were eligible for analysis. At the end of five months the balloon group had significantly more dysphagia and the calibre of the strictures in the balloon group had narrowed by a greater degree. The methods were equally safe(More)
The stability and dissolution properties of griseofulvin binary and ternary solid dispersions were evaluated. Solid dispersions of griseofulvin and hydroxypropyl methylcellulose acetate succinate (HPMCAS) were prepared using the spray drying method. A third polymer, poly[N-(2-hydroxypropyl)methacrylate] (PHPMA), was incorporated to investigate its effect on(More)
The effect of spray drying lactose alone and in the presence of polyethylene glycol 4000 was investigated. Lactose was added to distilled water to give concentrations of 10, 20, 30 and 40g/100ml at room temperature and each spray dried in turn. Identical samples were prepared to which polyethylene glycol (PEG) 4000 was added (12% by weight of lactose) prior(More)
Amorphous dispersions provide an excellent way of increasing dissolution rates of poorly soluble drugs, but there may be concerns about stability. One way of assessing the stability of amorphous is the study of relaxation. In this study the relaxation at the surface of amorphous solid dispersions (SDs) was evaluated using inverse gas chromatography (IGC). A(More)
Mass loss at elevated RH is an established method for determining the occurrence of crystallisation of an amorphous material. Through the combination of near infrared spectroscopy and gravimetric vapour sorption, it has been possible to show the transition of raffinose from its spray-dried amorphous form to a crystalline form without this characteristic(More)
The effect of adding a third polymer to immiscible binary solid dispersions was investigated. The model actives griseofulvin (GF), progesterone (PG) and phenindione (PD) were selected because they exemplify a key property of many poorly soluble molecules of having at least one hydrogen bonding acceptor moiety while not having any hydrogen bond donating(More)
PURPOSE To assess differences in surface energy due to processing induced disorder and to understand whether the disorder dominated the surfaces of particles. METHODS Inverse gas chromatography was used to compare the surface energies of crystalline, amorphous, and ball milled lactose. RESULTS The milling process made ca 1% of the lactose amorphous,(More)
Surfaces of pharmaceutical powders have been assessed using contact angle, inverse phase gas chromatography (IGC) and triboelectric (electrostatic) charging techniques. The suitability of the Dynamic Angle Tester (DAT), an instrument based on the sessile drop technique, in determining contact angles and then the surface energy of pharmaceutical powders was(More)