TY - JOUR
T1 - Transformations between Co-Amorphous and Co-Crystal Systems and Their Influence on the Formation and Physical Stability of Co-Amorphous Systems
AU - Wu, Wenqi
AU - Wang, Yixuan
AU - Löbmann, Korbinian
AU - Grohganz, Holger
AU - Rades, Thomas
PY - 2019/3/4
Y1 - 2019/3/4
N2 - The formation of co-amorphous and co-crystal systems are attractive formulation strategies for poorly water-soluble drugs. Intermolecular interactions between the drug and the coformer(s) play an important role in the formation of both systems, making the investigation of transformations between the two systems specifically interesting. The aim of this study thus was to investigate the transformation between the two systems and its influence on the formation and physical stability of co-amorphous systems. Carbamazepine (CBZ) along with benzoic acid, maleic acid, succinic acid, tartaric acid, saccharin, and nicotinamide were used as materials. First, CBZ-co-former co-crystals were prepared. Then the co-crystals and CBZ-co-former physical mixtures were ball milled to investigate the possible co-amorphization process. The XRPD and DSC results showed that CBZ and coformers tended to maintain (co-crystals as the starting material) or form co-crystals (physical mixtures as the starting material), rather than to form co-amorphous systems. Next, co-amorphization from CBZ-co-former physical mixtures via quench cooling was studied. While co-amorphous systems were obtained, the physical stability of these was very low, and the samples recrystallized to either co-crystal forms or the individual components. In conclusion, a possible transformation between the two systems was confirmed, but the resulting co-amorphous systems were highly unstable.
AB - The formation of co-amorphous and co-crystal systems are attractive formulation strategies for poorly water-soluble drugs. Intermolecular interactions between the drug and the coformer(s) play an important role in the formation of both systems, making the investigation of transformations between the two systems specifically interesting. The aim of this study thus was to investigate the transformation between the two systems and its influence on the formation and physical stability of co-amorphous systems. Carbamazepine (CBZ) along with benzoic acid, maleic acid, succinic acid, tartaric acid, saccharin, and nicotinamide were used as materials. First, CBZ-co-former co-crystals were prepared. Then the co-crystals and CBZ-co-former physical mixtures were ball milled to investigate the possible co-amorphization process. The XRPD and DSC results showed that CBZ and coformers tended to maintain (co-crystals as the starting material) or form co-crystals (physical mixtures as the starting material), rather than to form co-amorphous systems. Next, co-amorphization from CBZ-co-former physical mixtures via quench cooling was studied. While co-amorphous systems were obtained, the physical stability of these was very low, and the samples recrystallized to either co-crystal forms or the individual components. In conclusion, a possible transformation between the two systems was confirmed, but the resulting co-amorphous systems were highly unstable.
KW - co-amorphous systems
KW - co-crystal systems
KW - physical stability
KW - recrystallization
KW - transformation
UR - http://www.scopus.com/inward/record.url?scp=85060803080&partnerID=8YFLogxK
U2 - 10.1021/acs.molpharmaceut.8b01229
DO - 10.1021/acs.molpharmaceut.8b01229
M3 - Journal article
C2 - 30624075
AN - SCOPUS:85060803080
SN - 1543-8384
VL - 16
SP - 1294
EP - 1304
JO - Molecular Pharmaceutics
JF - Molecular Pharmaceutics
IS - 3
ER -