Crystals of PQQ disodium salt and how to make them (Mitsubishi Gas Chemical)

1. Key points of this patent

What it protects: Crystals of PQQ disodium salt with at most 7% water by weight, in one of two crystal forms defined by X-ray diffraction peaks, and how to make them. The key is to turn the original high-water crystals into new low-water crystal forms (Forms 1 and 2) by drying them under reduced pressure or heating them in edible oil.

2. What the specification says

The crystal in the examples (Form 1) had less water (9.6% → 0.7%) and higher purity (90.4% → 99.3%) than the comparative crystal precipitated with ethanol. In edible oil, it took longer to settle than the original crystal (0.5 → 30 minutes).

Item	Crystal compared	Claimed crystal	Where in the specification
Water content	9.6% (Comparative Example 1)	0.7% (Form 1)	Example 1; Comparative Example 1
Purity	90.4% (Comparative Example 1)	99.3% (Form 1)	Example 1; Comparative Example 1
Time for all crystals to settle in soybean oil	0.5 min (original crystal)	30 min (Form 1), 45 min (Form 2)	Example 6; Table 1

Item	Details
Patent number	US 9,174,983
Type	Substance patent (A patent that protects a new ingredient itself)
Related ingredient brand	BioPQQ (ingredient of Mitsubishi Gas Chemical, the patent holder)
Ingredients	Pyrroloquinoline Quinone Disodium Salt, Pyrroloquinoline Quinone
Holder / applicant	Mitsubishi Gas Chemical Company, Inc.
Filed	6/15/2012
Registered	11/3/2015
Expires	6/15/2032 (expected)

1. Key points of this patent

2. What the specification says

3. Patent details