Introduction

The characterisation of nasal formulations is a critical point. However, there are still no recommendations or guidelines in terms of standard approaches for evaluating the formulation's nasal deposition and/or coverage profile. This study optimises a method for quantifying silicone nasal cast deposition and coverage of liquid formulations using different nasal devices.

Objectives

The present work investigates the nasal deposition and coverage patterns of innovative nasal spray nozzles producing slow velocity soft mists, using a nasal cavity replica and a fluorescent dye.

Methods

The study of the deposition pattern of a fluorescent liquid formulation in a transparent nasal cast was carried out in both the presence and absence of a simulated inhalation flow. The extent of the deposition pattern was investigated using ImageJ and fluorescence in the nasal cast, quantified by fluorometric analysis. The particle size distribution and initial droplet velocity were determined using a laser diffractometer and a high-speed camera with a frame rate of 1000 fps.

Results

A uniform intranasal coverage was obtained with droplets of a volume median particle size (Dv50) between 15 and 25 µm in airflow between 10 and 30 L/min. In these conditions, aerosol formulations can be uniformly deposited in the vestibule and turbinate cavity nasal regions, with less than 10 % passing beyond the nasopharyngeal region.

Conclusion

The method applied allowed for the determination of the coverage of the nasal cast in different regions using images analysis and fluorometric analysis. Droplet velocity is a critical parameter in the deposition in the nasal cavity. With standard swirl nozzles, many droplets are found on the surface of the nasal vestibule. Soft mist nozzles produce smaller droplets at a much lower initial velocity (<1 m/s), resulting in a more uniform coverage.

中文翻译：

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使用创新的喷雾装置对鼻道沉积和药物制剂在硅胶鼻模中的覆盖进行荧光评估

介绍

鼻腔制剂的表征是一个关键点。然而，在评估制剂的鼻腔沉积和/或覆盖范围的标准方法方面仍然没有建议或指南。本研究优化了一种使用不同鼻腔装置量化硅胶鼻腔铸型沉积和液体制剂覆盖率的方法。

目标

目前的工作使用鼻腔复制品和荧光染料研究了产生慢速软雾的创新鼻喷雾喷嘴的鼻腔沉积和覆盖模式。

方法

在存在和不存在模拟吸入流的情况下，对荧光液体制剂在透明鼻腔模型中的沉积模式进行了研究。使用 ImageJ 和鼻模型中的荧光研究了沉积模式的范围，并通过荧光分析进行了量化。使用激光衍射仪和帧速率为 1000 fps 的高速相机测定粒径分布和初始液滴速度。

结果

在 10 至 30 L/min 的气流中，体积中值粒径 (Dv50) 的液滴在 15 至 25 µm 之间，获得均匀的鼻内覆盖。在这些情况下，气溶胶制剂可以均匀地沉积在前庭和鼻甲腔鼻区，只有不到 10% 的药物会超出鼻咽区。

结论

所应用的方法允许使用图像分析和荧光分析来确定不同区域的鼻铸件的覆盖范围。液滴速度是鼻腔沉积的关键参数。使用标准涡流喷嘴时，会在鼻前庭表面发现许多液滴。软雾喷嘴以低得多的初始速度 (<1 m/s) 产生较小的液滴，从而实现更均匀的覆盖。