Fig. 5: Pharmacokinetic study of L-Dopa under different dosing regimens.

a Intermittent L-Dopa dosing scheme in a normal rat: two doses (0.06 mg·g⁻¹ each) or four doses (0.03 mg·g⁻¹ each) at 30 min intervals, total 0.12 mg·g⁻¹. Created with BioRender.com/qrwgwmo. L-Dopa PKs under two-dose (b) and four-dose (c) injection regimens. Box and distribution plots show fluctuations of L-Dopa concentration (d) and L-Dopa variation rate (e) monitored under two-dose and four-dose regimens. The variation rate, calculated as the difference quotient of concentration, reflects the extent of change in L-Dopa levels. f Continuous drug administration scheme using an infusion pump. Created with BioRender.com/cuxc20n. g Continuous drug infusion scheme in a normal rat: four rates, total 0.12 mg·g⁻¹. Created with BioRender.com/5va7dto. h L-Dopa PK profiles under four infusion rates: ultra-high-speed (4 μg·g⁻¹·s⁻¹), high-speed (4 μg·g⁻¹·min⁻¹), medium-speed (2 μg·g⁻¹·min⁻¹), and low-speed (1 μg·g⁻¹·min⁻¹) continuous infusion. i Comparison of L-Dopa PK parameters under the four infusion rates. j Box and distribution plots show fluctuations of L-Dopa concentration monitored under four infusion rates. k Compilation of data on L-Dopa concentration and its variation rate in response to progressively increasing infusion rates within a single PK monitoring session. The mean variation rate was calculated at 30, 60, 90, 120, 180, 210, and 240 min. All box plots: mean (center), box = 25th–75th percentiles, whiskers = 1.5 × IQR.