| Texto completo | |
| Autor(es): |
Ekawa, Bruno
;
Diogo, Herminio P.
;
Castro, Ricardo A. E.
;
Caires, Flavio J.
;
Eusebio, M. Ermelinda S.
Número total de Autores: 5
|
| Tipo de documento: | Artigo Científico |
| Fonte: | Molecules; v. 28, n. 17, p. 13-pg., 2023-09-01. |
| Resumo | |
Coamorphous formation in binary systems of valsartan (Val) with 4,4'-bipyridine (Bipy) and trimethoprim (Tri) was investigated for mixtures with a mole fraction of 0.16 similar to 0.86 of valsartan and evaluated in terms of the glass transition temperature. The glass transition of the systems had a behavior outside the values predicted by the Gordon-Taylor equation, showing that Val-Bipy (hydrogen bonding between the components) had a lower deviation and Val-Tri (ionic bonding between the components) had a higher deviation. Mixtures of compositions 2:1 Val-Bipy and 1:1 Val-Tri were selected for further investigation and verified to be stable, as no crystallization was observed during subsequent heating and cooling programs. For these systems, the effective activation energy during glass transition was evaluated. Compared to pure valsartan, the system with the lower glass transition temperature (Val-Bipy) presented the highest effective activation energy, and the system with the higher glass transition temperature (Val-Tri) presented a lower effective activation energy. The results presented a good correlation between the data obtained from two different techniques to determine the fragility and effective activation energy: non-isothermal kinetic analysis by DSC and TSDC. (AU) | |
| Processo FAPESP: | 18/24378-6 - Síntese, caracterização e estudo termoanalítico de cocristais de Valsartana, Candesartana Cilexetila e Olmesartana medoxomila |
| Beneficiário: | Flávio Junior Caires |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |