Stabilizing reduced coenzyme Q10 and crystallizing it with acid (Kaneka)

1. Key points of this patent

What it protects: A method of protecting reduced coenzyme Q10 from oxidation by handling it in a solvent containing a strong acid, and of crystallizing it from that solvent. Because reduced coenzyme Q10 turns into the oxidized form easily in air, a little strong acid such as hydrochloric acid is added to limit oxidation during handling and crystallization.

2. What the specification says

Adding hydrochloric acid during crystallization left less of the oxidized form in the crystals than adding water instead (2.6% → 0.9%). Crystallizing under nitrogen gave 0.5%.

US 7,169,590: what the specification says (crystallized in air)

Item	With water (Comparative Example 1)	With hydrochloric acid (Example 7)	Where in the specification
Reduced : oxidized in the crystals (by weight)	97.4 : 2.6	99.1 : 0.9	Example 7; Comparative Example 1
Purity of reduced coenzyme Q10	97.2%	98.9%	Example 7; Comparative Example 1
Yield	95 mol%	95 mol%	Example 7; Comparative Example 1
Crystallized under nitrogen	—	99.5 : 0.5 (purity 99.3%)	Example 9

Item	Details
Patent number	US 7,169,590
Type	Process patent (A patent that protects a manufacturing method)
Related ingredient brand	Kaneka Ubiquinol and others (ingredients of Kaneka, the patent holder)
Ingredients	Ubiquinol
Holder / applicant	Kaneka Corporation
Filed	7/15/2002
Registered	1/30/2007
Expires	9/27/2022 (expired)
Notes

1. Key points of this patent

2. What the specification says

3. Patent details