Table 5.

Stability data for hydroxycitric acid (HCA) in male Sprague (SD) rat plasma, male Hsd:Sprague Dawley® SD® (HSD) rat plasma, GD18 HSD fetal homogenate, and in solution (1% formic acid/ASTM type 1 water)

Stability (RE %)	HCA
Freeze-Thaw SD Rat Plasma a	105.6 to 107.1 % Day 0
SD Rat Plasma (−70 °C) b	89.2 to 102.4 % Day 0
GD18 HSD Fetal Homogenate (−70 °C) c	92.3 to 103.2 % Day 0
Filtrate Stability, Refrigerated in Dark d	95.6 to 102.6 % Day 0
Filtrate Stability, Ambient in Light e	88.3 to 96.0 % Day 0
Analyte Solution Stability, Refrigerated in Dark f	≤±4.9 %REg
Internal Standard Solution Stability, Refrigerated in Dark h	≤±9.0 %REg

^aFour replicates matrix QCs at 2 levels (30 and 640 ng/mL); underwent two freeze and thaw cycles (~−70°C/ambient temperature)

^bFour replicates matrix QCs at 2 levels (30 and 300 ng/mL); stored at ~ −70°C for 762 days

^cFour replicates matrix QCs at 2 levels (90 and 2260 ng/g); stored at ~ −70°C for 476 days

^dFour replicates plasma QCs at 3 levels (15, 150, and 321 ng/mL); filtered, stored refrigerated in dark for 6 days, and injected with freshly prepared matrix calibration standards

^eFour replicates plasma QCs at 3 levels (15, 150, and 321 ng/mL); filtered, stored at ambient temperature in the light for 4 days, and injected with freshly prepared matrix calibration standards

^fFour replicates of a matrix QC sample at ~300 ng/mL prepared using HCA in 1% formic acid/water at ~ 500 μg/mL; stored refrigerated (~ 2-8°C) for 47 days

^g%RE = percent relative error

^hFour replicates of a matrix QC sample at ~ 300 ng/mL prepared using citric acid-¹³C_{6 in} 1% formic acid/water at 125 ng/mL; stored refrigerated (~ 2-8°C) for 47 days