New crystal form of R(+)-thioctic acid-L-lysinate and preparation method thereof

The invention relates to the field of pharmaceutical chemistry, specifically to a new crystal form of R(+)-thioctic acid-L-lysinate, namely its crystal form I and its preparation method. The invention also relates to a pharmaceutical composition containing the new crystal form and an application of the pharmaceutical composition in the preparation of drugs for treating paresthesia caused by diabetic peripheral neuropathy. By the use of Cu-K alpha radiation, the X-ray power diffraction of R(+)-thioctic acid-L-lysinate crystal form I has diffraction peaks at 5.012, 7.589, 10.072, 12.549, 15.036, 16.688, 18.627, 19.356, 25.064 and 27.611 when expressed with 2 theta degrees, wherein the error range of 2 theta value is +/- 0.2.