Novel Technology Allows Noninvasive Monitoring of Subcutaneous Drug Delivery Systems

According to a recent study published in Analytical Chemistry, microspatially offset low-frequency Raman spectroscopy (micro-SOLFRS) offers a new way to conduct in situ analysis of drug delivery systems (1).

Noninvasive monitoring of drug delivery systems is a hot topic in biomedical analysis. One of the most studied non-invasive drug delivery systems that have been studied in this field in transdermal drug delivery (TDD), which is less invasive and often used to treat medical conditions such as diabetes (2). However, a drug delivery method is only good if it succeeds in drug retention. As a result, it is important that methods exist that can monitor the effectiveness of drug delivery methods.

Transdermal drug delivery is a method of administering medications to patients through the skin, allowing specific active ingredients to be absorbed into the bloodstream. This technique is used to provide a controlled release of drugs over time, often using drug containing patches, gels, or creams. This approach bypasses the digestive system and reduces systemic side effects.

Recently, a team of researchers from the University of Copenhagen explored this topic. Looking to evaluate implant integrity and drug retention, the researchers proposed a new method for noninvasive monitoring of subcutaneous drug delivery systems (1). The goal of their study was to present another way to optimize therapeutic treatments. The study, led by Ben J. Boyd and Ka̅rlis Be̅rziņš, presented a method using microspatially offset low-frequency Raman spectroscopy (micro-SOLFRS) for in situ analysis of implant integrity and drug retention (1).

Read More: Analysis of Transdermal Patch Layers via Confocal Raman Microscopy

Subcutaneous implants have emerged as promising drug delivery systems, offering sustained release kinetics and improved patient compliance. However, monitoring their performance and integrity traditionally required invasive procedures or indirect methods (1). The new approach presented in the study sought to address these limitations by providing real-time insights into the status of implants and drug distribution (1).

Caffeine was used as the model drug in this study. Prototype implants were then placed beneath skin tissue samples, simulating real-world conditions. By employing micro-SOLFRS at various displacement settings, researchers achieved pseudo three-dimensional imaging (3D), enabling precise analysis of drug release dynamics (1).

Using micro-SOLFRS for this type of analysis proved to be advantageous in numerous ways. For one, the technique was able to distinguish temporal and spatial changes in implant erosion and drug transformation (1). By correlating spectroscopic data with high-performance liquid chromatography (HPLC) analysis, the team demonstrated the technique's accuracy in monitoring drug concentration changes over time (1).

Read More: 3D and Topographic Raman Imaging of Drug Delivery Systems

The findings in this study show that the new technique used opens up a new path for biomedical diagnostics. By offering nonintrusive, real-time monitoring of drug delivery systems, micro-SOLFRS could pave the way for personalized therapies and point-of-care technologies (1).

The study's findings also hold significant implications for various medical fields, including pharmacology and personalized medicine. By enabling clinicians to monitor drug release kinetics and implant integrity without invasive procedures, micro-SOLFRS could enhance treatment outcomes and minimize adverse effects (1).

As researchers continue to refine and expand upon this innovative technique, the future looks promising for noninvasive monitoring of drug delivery systems, bringing us one step closer to personalized medicine and enhanced patient care.

References

(1) Be̅rziņš, K.; Czyrski, G. S.; Aljabbari, A.; Heinz, A.; Boyd, B. J. In Situ Imaging of Subcutaneous Drug Delivery Systems Using Microspatially Offset Low-Frequency Raman Spectroscopy. Anal. Chem. 2024, 96 (16), 6408–6416. DOI: 10.1021/acs.analchem.4c00488

(2) Xie, Y.; Wu, H.; Chen, Z.; et al. Non-invasive Evaluation of Transdermal Drug Delivery Using 3-D Transient Triplet Differential (TTD) Photoacoustic Imaging. Photoacoustics 2023, 32, 100530. DOI: 10.1016/j.pacs.2023.100530