Effect of Short-Course Oral Ciprofloxacin on Isoflavone Pharmacokinetics following Soy Milk Ingestion in Healthy Postmenopausal Women

Table 3

Stability for assay of daidzein and genistein in human plasma.

Compound	Concentration; (ng/mL)	Short-term stability; (8 hours, n=3); %Remaining	Long-term stability; (3 months, n=3); %Remaining	Freeze-thaw stability; (n=3); %Remaining	Post-preparative stability (n=5); %Remaining
Daidzein	110	98.42	105.19	86.26	98.01
	2200	98.54	94.57	100.14	98.11
Average stability		98.48	99.88	93.20	98.06
Genistein	110	99.56	104.44	91.15	96.76
	2200	99.25	95.67	110.88	96.94
Average stability		99.40	100.05	101.02	96.85