Purpose

Being hydrophobic, paraffin wax is potentially useful for developing taste-masked or sustained release drug formulations. However, its high hydrophobicity also makes it challenging to achieve good embedment of a hydrophilic drug (e.g. paracetamol) due to the significant interfacial tension experienced. While spray congealing is an efficient technique of producing microparticles for pharmaceutical applications, there has been limited investigation on the use of paraffin wax in this technique.

Methods

A rapid method based on microscopic assessment was developed to screen paraffin wax blends containing surfactants for good extent of drug embedment. The rheological properties of the molten blends were investigated. Suitable blends were spray-congealed and the products characterised. Statistical analysis of the data and drug release modelling were carried out.

Results

Drug-loaded paraffin wax was too viscous for spray congealing. The addition of surfactants decreased the melt viscosity and improved sprayability and microparticle yield. The microparticles showed high paracetamol encapsulation efficiency, with drug particles well-embedded in some formulations. The drug release was effected through diffusion and erosion of the matrix material.

Conclusion

The use of surfactants allowed successful embedment of paracetamol within spray-congealed microparticles, enabling taste-masking and sustained release.

中文翻译：

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表面活性剂对喷雾凝结石蜡蜡共混物熔体粘度和包埋程度的影响

目的

作为疏水剂，石蜡可能对开发掩味或缓释药物制剂有用。然而，由于经历了显着的界面张力，其高疏水性也使其难以获得亲水性药物（例如对乙酰氨基酚）的良好包埋。尽管喷雾凝结是生产用于药物应用的微粒的有效技术，但是对于在该技术中使用石蜡的研究还很有限。

方法

开发了一种基于微观评估的快速方法，以筛选含有表面活性剂的石蜡共混物，以实现良好的药物包埋程度。研究了熔融共混物的流变性。将合适的共混物喷雾凝结，并对产物进行表征。进行数据的统计分析和药物释放模型。

结果

载药的石蜡太粘，无法喷雾凝结。表面活性剂的添加降低了熔体粘度并改善了可喷涂性和微粒产率。微粒显示出较高的对乙酰氨基酚包封效率，药物颗粒已很好地嵌入某些制剂中。药物的释放是通过基质材料的扩散和腐蚀来实现的。

结论

使用表面活性剂可将对乙酰氨基酚成功嵌入喷雾凝结的微粒中，从而掩盖味道并持续释放。