Pharmaceutical and medicinal printing technologies allow personalization and on-demand manufacturing of drug and medicinal products. Being able to manufacture patient tailored dosage forms or medical devices in a pharmacy, medical office, dental laboratory, or hospital at the point of care raises new demands on quality control procedures. For Fused Deposition Modeling, for example, it must be ensured that the starting materials, the (drug-loaded) filaments, are not accidentally exchanged by the operator. This study investigated the potential of colorimetric measurements for direct and indirect determination of the identity of extruded filaments consisting of polymer matrix, different API and/or coloring agents. Since reflection measurements were affected by surface properties of the filaments, a self-constructed filament holder was utilized with an optical fiber positioned in a 180° angle to a white light LED to perform transmission measurements. It was possible to distinguish filaments with different API concentrations by their color values, taking into account that transmission partially decreased by increased API concentration. Therefore, the intensity of the light source had to be adjusted depending on the transparency of the filament. It was shown that colorimetry can be used as a quality control tool to detect differences in drug-loading and is able to distinguish various extruded batches. Additionally, if differences in API/polymer concentrations do not lead to significant changes in L*a*b values, coloring agents were used as additives in low concentrations to color code filaments. In future studies, the setup must be supplemented with a standardized light source and obscuring filters for light intensity adjustments.

中文翻译：

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引入纤维辅助比色测量作为热熔挤出长丝的质量控制工具


制药和医药印刷技术允许个性化和按需制造药品和医药产品。能够在药房、医疗办公室、牙科实验室或医院的护理点生产患者定制的剂型或医疗器械，对质量控制程序提出了新的要求。例如，对于熔融沉积建模，必须确保操作员不会意外更换起始材料（载药）细丝。本研究调查了比色测量直接和间接测定由聚合物基质、不同 API 和/或着色剂组成的挤出长丝特性的潜力。由于反射测量受到灯丝表面特性的影响，因此使用自制的灯丝支架和与白光 LED 成 180° 角的光纤来执行传输测量。考虑到 API 浓度增加导致透射率部分下降，可以通过颜色值区分具有不同 API 浓度的灯丝。因此，必须根据灯丝的透明度来调整光源的强度。结果表明，比色法可用作质量控制工具来检测载药量的差异，并能够区分不同的挤出批次。此外，如果 API/聚合物浓度的差异不会导致 L*a*b 值发生显着变化，则使用低浓度着色剂作为添加剂对长丝进行颜色编码。在未来的研究中，该装置必须辅以标准化光源和用于光强度调整的模糊滤光片。