RESUMO
Three mesoporous silica excipients (Syloid? silicas AL-1 FP, XDP 3050 and XDP 3150) were formulated with a model drug known for its poor aqueous solubility, namely phenylbutazone, in an attempt to enhance the extent and rate of drug dissolution. Although other forms of mesoporous silica have been investigated in previous studies, the effect of inclusion with these specific Syloid? silica based excipients and more interestingly, with phenylbutazone, is unknown. This work reports a significant enhancement for both the extent and rate of drug release for all three forms of Syloid? silica at a 1:1 drug:silica ratio over a period of 30 min. An explanation for this increase was determined to be conversion to the amorphous form and an enhanced drug loading ability within the pores. Differences between the release profiles of the three silicas were concluded to be a consequence of the physicochemical differences between the three forms. Overall, this study confirms that Syloid? silica based excipients can be used to enhance dissolution, and potentially therefore bioavailability, for compounds with poor aqueous solubility such as phenylbutazone. In addition, it has been confirmed that drug release can be carefully tailored based on the choice of Syloid? silica and desired release profile.
RESUMO
This paper addresses the modification of poly(dimethylsiloxane), i.e. PDMS, using plasma surface treatment and a novel application of the membrane created. A set of model compounds were analysed to determine their permeation through PDMS, both with and without plasma treatment. It was found that plasma treatment reduced permeation for the majority of compounds but had little effect on some compounds, such as caffeine, with results indicating that polarity plays an important role in permeation, as is seen in human skin. Most importantly, a direct correlation was observed between plasma-modified permeation data and literature data through calculation of membrane permeability (Kp) values suggesting plasma-modified silicone membrane (PMSM) could be considered as a suitable in vivo replacement to predict clinical skin permeation.
RESUMO
This paper addresses the modification of poly(dimethylsiloxane), i.e. PDMS, using plasma surface treatment and a novel application of the membrane created. A set of model compounds were analysed to determine their permeation through PDMS, both with and without plasma treatment. It was found that plasma treatment reduced permeation for the majority of compounds but had little effect on some compounds, such as caffeine, with results indicating that polarity plays an important role in permeation, as is seen in human skin. Most importantly, a direct correlation was observed between plasma-modified permeation data and literature data through calculation of membrane permeability (Kp) values suggesting plasma-modified silicone membrane (PMSM) could be considered as a suitable in vivo replacement to predict clinical skin permeation.
RESUMO
This study investigated the development of a novel approach to surface characterization of drug poly-morphism and the extension of the capabilities of this method to perform ‘real time’ in situ measure-ments. This was achieved using diffuse reflectance visible (DRV) spectroscopy and dye deposition, using the pH sensitive dye, thymol blue (TB). Two polymorphs, SFN-β and SFN-γ, of the drug substance sul-fanilamide (SFN) were examined. The interaction of adsorbed dye with polymorphs showed different behavior, and thus reported different DRV spectra. Consideration of the acid/base properties of the morphological forms of the drug molecule provided a rationalization of the mechanism of differential coloration by indicator dyes. The kinetics of the polymorphic transformation of SFN polymorphs was monitored using treatment with TB dye and DRV spectroscopy. The thermally-induced transformation fitted a first-order solid-state kinetic model (R2 ? 0.992), giving a rate constant of 2.43 ? 10 ? 2 s ? 1.
RESUMO
This project which developed from an excercise in drama for patients at the Acute Psychiatric Unit, Princess Margaret Hospital, was aimed at challenging the attitudes of communities of Dominica towards their mentally ill people. A patient's drama group aided by staff and the Movement for Cultural Awareness (MCA), used popular theatre techniques to plan, practice and film a 45-minute video. The result, "Aaron's Story" was adapted from a true case history and shows a successful family man who becomes mentally ill and recovers after treatment in hospital, only to be publicly rejected by family and friends and commit suicide. The direct message of the film is the community's rejection of the mentally ill which leads to tragic results, while indirectly, the film demonstrates the successful and convincing roles of the patients as performers. The video is used as part of an educational programme aimed at 11 main population centres and 6 schools throughout Dominica. Evaluation of the project is done through questionnaires, interviews and discussions after the video's pesentation. The project helped to build confidence, assertiveness and social skills in patients, and provided a collective voice for those usually unheard (AU)