There is a substantial demand for absorptive dissolution tests, as single vessel dissolution experiments were originally not designed for testing supersaturating systems. Current approaches suffer from inadequate mass transfer of the dissolved active from the dissolution site, discrepancies in the fluid volume compared to in vivo intestinal fluid volumes or the dilution of functional excipients. In this work a novel dissolution apparatus was developed that enables adjustable mass transfer of the active through a membrane, while retaining the functional polymeric excipients at the dissolution site.
View Article and Find Full Text PDFThe formulation of amorphous solid dispersions (ASDs) is an effective way to improve the bioavailability of poorly water-soluble active pharmaceutical ingredients (APIs). The combination of an amorphous state of the drug and the presence of crystallization-inhibiting polymers retains a high amount of dissolved API over time. ASDs with ketoconazole and different polymers were manufactured by spray drying and their characteristics as well as performance were analyzed.
View Article and Find Full Text PDFPowder-injectors use gas propulsion to deposit lyophilised drug or vaccine particles in the epidermal and sub epidermal layers of the skin. We prepared dry-powder (Tg = 45.2 ± 0.
View Article and Find Full Text PDFInjections with a hypodermic needle and syringe (HNS) are the current standard of care globally, but the use of needles is not without limitation. While a plethora of needle-free injection devices exist, vaccine reformulation is costly and presents a barrier to their widespread clinical application. To provide a simple, needle-free, and broad-spectrum protein antigen delivery platform, we developed novel potassium-doped hydroxyapatite (K-Hap) microparticles with improved protein loading capabilities that can provide sustained local antigen presentation and release.
View Article and Find Full Text PDFThe central importance for global public health policy of delivering life-saving vaccines for all children makes the development of efficacious and safe needle-free alternatives to hypodermic needles, preferably in a thermostable form, a matter of pressing urgency. This paper comprehensively reviews past in vivo studies on intradermal powder immunization with vaccine formulations that do not require refrigeration. Particular emphasis is given to the immune response in relation to antigen adjuvantation.
View Article and Find Full Text PDFPurpose: In controlled laboratory studies of hyperthermia and thermal ablation, translucent hydrogels containing bovine serum albumin (BSA) are often employed as tissue-mimicking materials due to the change in their opacity that takes place as they accumulate heat damage. In this work we demonstrate the biological relevance of this optical metric of thermal damage, as well as establish the physical mechanisms that link it with quantifiable damage to the proteins embedded in the gel.
Materials And Methods: We applied Fourier transform infrared (FTIR) spectroscopy, turbidity analysis using ultraviolet-visible (UV/VIS) spectroscopy, and size exclusion chromatography (SEC) to samples of heat-treated, aqueous bovine serum albumin (BSA).
Needle-free injection is a novel technique for transdermal drug and vaccine delivery, the efficacy of which depends on the number density and mean penetration depth of particles beneath the skin. To date, these parameters have been assessed optically, which is time-consuming and unsuitable for use in vivo. The present work describes the development of a scanning acoustic microscopy technique to map and size particle distributions following injection.
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