Non-invasive in vivo monitoring of circulating amphotericin b using multi-wavelength photoplethysmography

A novel multi-wavelength photoplethysmograph (PPG), previously utilized to quantify optically absorptive circulating gold nanoparticles, has demonstrated the potential to enhance therapeutic treatment predictability as pharmacokinetic metrics are provided throughout the intravenous delivery and clearance phase of amphotericin b (injected in the lipid form Abelcet®) in real-time. This report demonstrates how the PPG could be used to assess the real-time bioavailability of intravenously delivered optically-absorbing therapeutic agents. The drug currently under investigation is antifungal amphotericin b (absorption peak ~355 nm). We describe how the algorithm has been adapted to quantify the concentration of amphotericin b in the pulsatile, circulating blood based on its extinction at three wavelengths (355, 660 and 940 nm) corresponding to the peaks of amphotericin b and wavelengths for oxygen saturation measurements, respectively. We show an example of the system collecting data representing the baseline, injection, and the clearance phases. The PPG device showed a measurement range of concentrations between 0.0987 mg/mL to 0.025mg/ml in blood. An examination of the data obtained suggests that the system is well suited to sense the concentration of amphotericin b at a therapeutic dose (≈5 mg/kg/day).