Investigation of the formation process of two piracetam cocrystals during grinding

TY - JOUR

T1 - Investigation of the formation process of two piracetam cocrystals during grinding

AU - Rehder, Sönke

AU - Klukkert, Marten

AU - Löbmann, Korbinian

AU - Strachan, Clare J.

AU - Sakmann, Albrecht

AU - Gordon, Keith

AU - Rades, Thomas

AU - Leopold, Claudia S.

PY - 2011/12

Y1 - 2011/12

N2 - Cocrystal formation rates during dry grinding and liquid-assisted grinding were investigated by X-ray powder diffractometry and Raman spectroscopy. Two polymorphic forms of piracetam were used to prepare known piracetam cocrystals as model substances, i.e.,piracetam-citric acid and piracetam-tartaric acid cocrystals. Raman spectroscopy in combination with principal component analysis was used to visualize the cocrystal formation pathways. During dry grinding, cocrystal formation appeared to progress via an amorphous intermediate stage, which was more evident for the piracetam-citric acid than for the piracetam-tartaric acid cocrystal. It was shown that liquid-assisted grinding led to faster cocrystal formation than dry grinding, which may be explained by the higher transformation rate due to the presence of liquid. The cocrystal formation rate did not depend on the applied polymorphic form of the piracetam and no polymorphic cocrystals were obtained.

AB - Cocrystal formation rates during dry grinding and liquid-assisted grinding were investigated by X-ray powder diffractometry and Raman spectroscopy. Two polymorphic forms of piracetam were used to prepare known piracetam cocrystals as model substances, i.e.,piracetam-citric acid and piracetam-tartaric acid cocrystals. Raman spectroscopy in combination with principal component analysis was used to visualize the cocrystal formation pathways. During dry grinding, cocrystal formation appeared to progress via an amorphous intermediate stage, which was more evident for the piracetam-citric acid than for the piracetam-tartaric acid cocrystal. It was shown that liquid-assisted grinding led to faster cocrystal formation than dry grinding, which may be explained by the higher transformation rate due to the presence of liquid. The cocrystal formation rate did not depend on the applied polymorphic form of the piracetam and no polymorphic cocrystals were obtained.

KW - biology

KW - chemistry

U2 - 10.3390/pharmaceutics3040706

DO - 10.3390/pharmaceutics3040706

M3 - Journal article

C2 - 24309304

SN - 1999-4923

VL - 3

SP - 706

EP - 722

JO - Pharmaceutics

JF - Pharmaceutics

IS - 4

ER -