TY - JOUR

T1 - Preparation and characterization of spray-dried co-amorphous drug-amino acid salts

AU - Jensen, Katrine Birgitte Tarp

AU - Blaabjerg, Lasse Ingerslev

AU - Lenz, Elisabeth

AU - Bohr, Adam

AU - Grohganz, Holger

AU - Kleinebudde, Peter

AU - Rades, Thomas

AU - Löbmann, Korbinian

N1 - © 2015 Royal Pharmaceutical Society.

PY - 2016/5

Y1 - 2016/5

N2 - OBJECTIVES: Recently, co-amorphous drug-amino acid mixtures were introduced as a promising alternative to other amorphous stabilization approaches such as the use of polymers to form glass solutions. So far, these co-amorphous mixtures have been mainly prepared via vibrational ball milling on a lab scale. In this study, spray-drying was investigated as a scale up preparation method for co-amorphous indomethacin (IND)-amino acid mixtures. In addition, the physico-chemical properties of the different co-amorphous systems were investigated with respect to the amino acids' ability towards co-amorphous salt formation.METHODS: The mixtures were characterized for their solid state properties using differential scanning calorimetry, thermogravimetric analysis and X-ray powder diffraction. Fourier-transform infrared spectroscopy was used to analyze molecular interactions. Furthermore, intrinsic dissolution behaviour, and physical stability at various storage conditions, were examined.KEY FINDINGS: Results showed that IND could be converted into an amorphous form in combination with the amino acids arginine (ARG), histidine (HIS) and lysine (LYS) by spray-drying. Solid state characterization revealed elevated glass transition temperatures for all mixtures compared with the pure amorphous drug due to co-amorphization with the amino acids. Furthermore, strong intermolecular interactions in the form of salt/partial salt formation between the drug and amino acids were seen for all blends. All mixtures were physically stable (>10 months) at room temperature and 40°C under dry conditions. Intrinsic dissolution of the co-amorphous mixtures showed an improved dissolution behaviour under intestinal pH conditions for IND-ARG compared with the crystalline and amorphous forms of the drug. On the other hand, IND-LYS and IND-HIS revealed no significant improvement in the intrinsic dissolution rate of IND due to recrystallization of IND during dissolution.CONCLUSIONS: It could be shown that strong intermolecular interactions between drug and co-amorphous coformer that persist during the dissolution are crucial to prevent recrystallization and to enhance dissolution of a co-amorphous formulation.

AB - OBJECTIVES: Recently, co-amorphous drug-amino acid mixtures were introduced as a promising alternative to other amorphous stabilization approaches such as the use of polymers to form glass solutions. So far, these co-amorphous mixtures have been mainly prepared via vibrational ball milling on a lab scale. In this study, spray-drying was investigated as a scale up preparation method for co-amorphous indomethacin (IND)-amino acid mixtures. In addition, the physico-chemical properties of the different co-amorphous systems were investigated with respect to the amino acids' ability towards co-amorphous salt formation.METHODS: The mixtures were characterized for their solid state properties using differential scanning calorimetry, thermogravimetric analysis and X-ray powder diffraction. Fourier-transform infrared spectroscopy was used to analyze molecular interactions. Furthermore, intrinsic dissolution behaviour, and physical stability at various storage conditions, were examined.KEY FINDINGS: Results showed that IND could be converted into an amorphous form in combination with the amino acids arginine (ARG), histidine (HIS) and lysine (LYS) by spray-drying. Solid state characterization revealed elevated glass transition temperatures for all mixtures compared with the pure amorphous drug due to co-amorphization with the amino acids. Furthermore, strong intermolecular interactions in the form of salt/partial salt formation between the drug and amino acids were seen for all blends. All mixtures were physically stable (>10 months) at room temperature and 40°C under dry conditions. Intrinsic dissolution of the co-amorphous mixtures showed an improved dissolution behaviour under intestinal pH conditions for IND-ARG compared with the crystalline and amorphous forms of the drug. On the other hand, IND-LYS and IND-HIS revealed no significant improvement in the intrinsic dissolution rate of IND due to recrystallization of IND during dissolution.CONCLUSIONS: It could be shown that strong intermolecular interactions between drug and co-amorphous coformer that persist during the dissolution are crucial to prevent recrystallization and to enhance dissolution of a co-amorphous formulation.

U2 - 10.1111/jphp.12458

DO - 10.1111/jphp.12458

M3 - Journal article

C2 - 26245703

VL - 68

SP - 615

EP - 624

JO - Journal of Pharmacy and Pharmacology

JF - Journal of Pharmacy and Pharmacology

SN - 0022-3573

IS - 5

ER -