Online polarization error suppressed optical vector analyzer based on Bayesian optimization.

An optical vector analyzer (OVA) based on orthogonal polarization interrogation and polarization diversity detection is widely used to measure an optical device's loss, delay, or polarization-dependent features. Polarization misalignment is the OVA's primary error source. Conventional offline polarization alignment using a calibrator greatly reduces the measurement reliability and efficiency. In this Letter, we propose an online polarization error suppression method using Bayesian optimization. Our measurement results are verified by a commercial OVA instrument that uses the offline alignment method. The OVA featuring online error suppression will be widely used in the production of optical devices, not just in the laboratory.

Effect of CYP3A5*3 polymorphism on pharmacokinetic drug interaction between tacrolimus and amlodipine.

The objective of this study was to evaluate the effect of the CYP3A5*3 allele on the pharmacokinetics of tacrolimus and amlodipine, and drug-drug interactions between them in healthy subjects. Pharmacokinetic drug interactions between tacrolimus and amlodipine were evaluated in a randomized, 3-period, 6-sequence crossover study in healthy Chinese volunteers according to CYP3A5 genotype. A single-dose and multiple-dose study were designed. A 96-h pharmacokinetic study followed either tacrolimus or amlodipine dose, and the washout periods between the study phases were 14 days. In the single-dose study, apparent oral clearance (CL/F) of tacrolimus (5 mg) in CYP3A5 expressers was 3.8-fold (p = 0.008) higher than that in CYP3A5 non-expressers. Amlodipine decreased mean tacrolimus CL/F in CYP3A5 expressers by 2.2-fold (p = 0.005), while it had no effect on that in CYP3A5 non-expressers. The CL/F of amlodipine in CYP3A5 non-expressers was 2.0-fold (p = 0.001) higher than that in CYP3A5 expressers. Tacrolimus increased mean amlodipine CL/F in CYP3A5 expressers by 1.4-fold (p = 0.016) while it had no effect on that in CYP3A5 non-expressers. Tacrolimus slightly reduced the AUC0-∞ of amlodipine in both CYP3A5 expressers and non-expressers. Dose adjustment of tacrolimus should be considered according to CYP3A5*3 genetic polymorphism when tacrolimus is coadministered with amlodipine.

Effect of amlodipine on the pharmacokinetics of tacrolimus in rats.

1. The immunosuppressant tacrolimus (TAC) is a substrate of cytochrome P450 3A2 (CYP3A2) and P-glycoprotein (P-gp) in rats. Amlodipine (AML) is an inhibitor of CYP3A2 in rats. We investigated the effect of AML on the pharmacokinetics of TAC in rats. 2. When co-administered with TAC orally or intravenously, AML decreased the oral clearance and raised the blood concentration of TAC in rats, but the T1/2 of TAC was not significantly affected by AML. Upon oral administration of TAC, the effect of 15 mg/kg of AML on the AUC of TAC was lower than that seen with 5 or 10 mg/kg. However, upon intravenous TAC administration, the effect of 15 mg/kg of AML on the AUC of TAC was higher than that seen with 5 mg/kg. 3. AML is an inhibitor of P-gp and CYP3A2 in rats. If AML and TAC are co-administered orally, AML elicits greater inhibition in P-gp than CYP3A2 during first-pass metabolism. If AML is given orally and TAC given intravenously concurrently, AML mainly inhibits CYP3A2 activity and increases the blood concentration of TAC. There are significant pharmacokinetic interactions between TAC and AML. AML raises the blood concentration of TAC in rats probably by inhibiting P-gp and CYP3A2.