School of Pharmacy, Queen's University Belfast, Belfast, UK.
Int J Pharm. 2012 Feb 28;423(2):326-34. doi: 10.1016/j.ijpharm.2011.11.018. Epub 2011 Nov 15.
Poly(vinyl alcohol)-tetrahydroxyborate (PVA-THB) hydrogels are dilatant formulations with potential for topical wound management. To support this contention, the physical properties, rheological behaviour and component release of candidate formulations were investigated. Oscillatory rheometry and texture profile analysis were used at room temperature and 37 °C. Results showed that it was possible to control the rheological and textural properties by altering component concentration and modifying the type of PVA polymer used. Hydrogels made using PVA grades with higher degrees of hydrolysis displayed favourable characteristics from a wound healing perspective. In vitro release of borate and PVA were assessed in order to evaluate potential clinical dosing of free species originating from the hydrogel structure. Component diffusion was influenced by both concentration and molecular weight, where relevant, with up to 5% free PVA cumulative release observed after 30 min. The results of this study demonstrated the importance of poly(vinyl alcohol) selection for ensuring appropriate gel formation in PVA-THB hydrogels. The benefits of higher degrees of hydrolysis, in particular, included lower excipient release and reduced bioadhesion. The unique physical characteristics of these hydrogels make them an appealing delivery vehicle for chronic and acute wound management purposes.
聚乙烯醇-四羟基硼酸盐（PVA-THB）水凝胶是一种具有潜在局部伤口管理作用的膨胀性配方。为了支持这一论点，研究了候选配方的物理性质、流变行为和成分释放。在室温及 37°C 下，使用振荡流变学和质地分析。结果表明，可以通过改变成分浓度和改变使用的 PVA 聚合物类型来控制流变学和质地特性。从伤口愈合的角度来看，具有更高水解度的 PVA 等级制成的水凝胶具有良好的特性。评估了硼酸盐和 PVA 的体外释放，以评估源自水凝胶结构的游离物质的潜在临床剂量。在相关情况下，浓度和分子量都会影响成分扩散，30 分钟后可观察到高达 5%的游离 PVA 累积释放。这项研究的结果表明，对于确保 PVA-THB 水凝胶中适当的凝胶形成，选择聚乙烯醇的重要性。特别是，更高水解度的优点包括更低的赋形剂释放和减少生物黏附。这些水凝胶独特的物理特性使它们成为慢性和急性伤口管理的有吸引力的药物输送载体。
