Centre for Pharmaceutical Innovation(CPI), Clinical and Health Sciences, University of South Australia, Adelaide, SA, 5000, Australia.
Small Animal Specialist Hospital, Adelaide, SA, 5067, Australia.
BMC Vet Res. 2023 Feb 9;19(1):39. doi: 10.1186/s12917-023-03596-2.
Otitis externa is a commonly diagnosed dermatological disorder in canines. The pathogens primarily involved in canine otitis externa (COE) include Staphylococcus pseudintermedius, Pseudomonas aeruginosa, Proteus mirabilis, and Malassezia pachydermatis. As COE tends to be superficial, medications delivered topically are often effective and practical in managing the condition. As such, there is a wide variety of approved topical products currently available in the market. The efficacy of topical dosage forms can be dependent on various factors such as the pharmacology of active constituents and the physicochemical properties of the formulation, including pH, viscosity, spreadability, and bio-adhesion. Currently, there is a lack of published literature available on the optimal properties of topical COE products. In this study, we compared the physicochemical properties of nine commercially available otic veterinarian products in Australia used clinically to manage COE.
Based on our comparative analysis, the pH (6.26 ± 0.04) of an aqueous-based product was similar to a healthy dog's external auditory canal. Products containing polymers exhibited higher viscosity and bio-adhesion. Spreadability was inversely related to viscosity and Osurnia ® a product with high viscosity demonstrated the lowest spreadability. Aqueous-based otic products showed better syringebility whereas oil-based systems required higher force to expel the products. Variability in droplet size was noted. Derm Otic, Baytril Otic, and Aurizon Ear Drops had the lower standard deviation which indicates they would give a more consistent dose.
Findings from this work provide considerations for industry researchers or formulation scientists working in the area of otic dosage formulations.
外耳炎是犬类常见的皮肤科疾病。犬外耳炎（COE）的主要病原体包括中间葡萄球菌、绿脓假单胞菌、奇异变形杆菌和厚皮马拉色菌。由于 COE 往往是浅表性的，局部使用药物通常在治疗该病方面是有效和实用的。因此，目前市场上有各种各样的批准的局部产品。局部剂型的疗效可能取决于多种因素，如活性成分的药理学和制剂的物理化学性质，包括 pH 值、粘度、铺展性和生物粘附性。目前，关于局部 COE 产品的最佳特性，缺乏已发表的文献。在这项研究中，我们比较了澳大利亚临床上用于治疗 COE 的九种市售耳科兽医产品的物理化学性质。
根据我们的比较分析，一种水基产品的 pH 值（6.26±0.04）与健康犬的外耳耳道相似。含有聚合物的产品表现出更高的粘度和生物粘附性。铺展性与粘度呈反比，具有高粘度的 Osurnia®产品表现出最低的铺展性。水基耳科产品显示出更好的可推注性，而油基系统需要更大的力才能排出产品。注意到滴头尺寸的变化。Derm Otic、Baytril Otic 和 Aurizon Ear Drops 的标准偏差较低，这表明它们会提供更一致的剂量。
这项工作的结果为从事耳科制剂领域的行业研究人员或制剂科学家提供了一些考虑因素。
