With increasing protein concentrations, therapeutic protein formulations are increasingly demonstrating significant deviations from ideal dilute solution behavior due to protein-protein interactions. These interactions lead to unique biophysical challenges in the administration of biopharmaceuticals
Monitoring the viscoelastic properties of skin in liquid environments using quartz crystal microbalance
β Scribed by N. Sanjeeva Murthy; Fahmi Bedoui; Brian E. Kilfoyle; Carmine Iovine; Bozena Michniak-Kohn; Joachim Kohn
- Publisher
- John Wiley and Sons
- Year
- 2011
- Tongue
- English
- Weight
- 306 KB
- Volume
- 100
- Category
- Article
- ISSN
- 0022-3549
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β¦ Synopsis
Quartz crystal microbalance (QCM) with dissipation can be used to measure the response of the human stratum corneum (SC) attached to the QCM crystal, as it adsorbs or desorbs active ingredients from a liquid medium. The method was demonstrated with the sorption of poly(diallyl dimethyl ammonium chloride), a cationic polymer widely used in formulations for topical and transdermal applications. Using 14-mm diameter SC coupons attached to the QCM crystals with an adhesive, up to five overtones (up to 11th harmonic) were obtained and the response was analyzed using a Voigt model. The adhesive layer could be regarded as a rigid substrate, and the skin with overlaying fluid was modeled as a soft layer underneath a fluid medium. Limited modeling tools that are currently available were used to interpret the observed response in terms of physical parameters such as the changes in thickness, shear modulus, and viscosity. The high sensitivity of the technique demonstrates the possibility of using small samples of human skin for in vitro studies in a variety of topical and transdermal drug delivery applications and in the evaluation of skin care products.
π SIMILAR VOLUMES
A novel viscous sensor utilizing AT-cut quartz crystal to monitor the viscosity of fermentation broth was developed. The sensor system was constructed from the piezoelectric quartz crystal fixed to the cell, exposing only one side of the quartz crystal electrode, an oscillating circuit, a peak level