Publications by authors named "Daniel L Parsons"

The aim of this study was to improve the dissolution rate of efavirenz (EFV) by formulating a physically stable dispersion in polymers. Hot-melt extrusion (HME) was used to prepare solid solutions of EFV with Eudragit EPO (a low-glass transition polymer) or Plasdone S-630 (a high-glass transition polymer). The drug-polymer blends were characterized for their thermal and rheological properties as a function of drug concentration to understand their miscibility and processability by HME.

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This paper investigates the microneedle (MN) mediated in vitro transdermal iontophoretic delivery of prochlorperazine edisylate (PE) across dermatomed human skin. The Dermarollerâ„¢ induced microchannels were visualized using methylene blue staining and scanning electron microscopy. In vitro skin permeation studies were performed using vertical static Franz diffusion cells.

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The objective of this study was to formulate genistein as a topical gel with various penetration enhancers for increased permeation and retention in human skin. The high performance liquid chromatography assay method was validated for precision and reproducibility. The intra-day and inter-day precision as represented by the coefficient of variation (CV) of the peak areas were <0.

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Transdermal iontophoretic delivery of selegiline hydrochloride (SH) across dermatomed human skin was studied. Electrochemical stability and various factors affecting the skin permeation were investigated. SH was stable under the influence of an electrical field.

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Background: Gefitinib, an anticancer drug, has an extremely low aqueous solubility, and its oral absorption is limited by its dissolution rate. The solubility and dissolution of gefitinib can be improved by complexation with cyclodextrins (CDs).

Methods: Phase solubility studies of gefitinib with hydroxypropyl betaCD (HPbetaCD) and randomly methylated betaCD (RMbetaCD) in n various aqueous systems was conducted to characterize the complexes in the liquid state.

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Efavirenz (EFV) is an oral antihuman immunodeficiency virus type 1 drug with extremely poor aqueous solubility. Thus, its gastrointestinal absorption is limited by the dissolution rate of the drug. The objective of this study was to characterize the inclusion complexes of EFV with beta-cyclodextrin (beta-CD), hydroxypropyl beta-CD (HPbetaCD), and randomly methylated beta-CD (RMbetaCD) to improve the solubility and dissolution of EFV.

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The objective of this study was to develop sustained release Poloxamer 407 (P407) gel formulations of ceftiofur for treating foot infections in cattle. The formulations contained 25-35% (w/v) P407 alone or with polyvinyl pyrrolidone (PVP), carboxy methylcellulose (CMC), or hydroxylpropyl methylcellulose (HPMC) as an additive. The in-vitro release profiles of ceftiofur from the P407 formulations and the gel dissolution profiles were obtained simultaneously.

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