Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Carbohydr Polym ; 291: 119542, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-35698372

RESUMO

Characterization and tuning of the porosity of amorphous starch materials are important for many applications, including controlled release of encapsulated proteins. The porosities of these materials in dry and hydrated states can have different physicochemical origins and properties. Here, porosities of dry cross-linked starch microspheres and their hydration-induced transformations were characterized by small angle X-ray scattering, scanning electron and optical microscopies, thermogravimetric analysis, sorption calorimetry, nitrogen sorption, and helium-pycnometry. The analyses revealed that dry microspheres consist of porous cores with pore diameters below 100 nm and shells which appeared to be denser but contained wider pores (100-300 nm). The outer crust of the microspheres shell is non-porous, which restricts diffusion of nitrogen, water, and ethanol. Partial hydration triggered an irreversible collapse of dry porosity at 12 wt% water. Further hydration resulted in interfacial changes and promoted wet porosity, related to characteristic distances between polymer chains.


Assuntos
Desidratação , Amido , Humanos , Microesferas , Nitrogênio , Porosidade , Amido/química , Água/química
2.
ChemMedChem ; 9(4): 724-6, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24504569

RESUMO

Solubility is a frequently recurring issue within pharmaceutical industry, and new methods to proactively resolve this are of fundamental importance. Here, a novel methodology is reported for intrinsic solubility improvement, using in silico prediction of crystal structures, by perturbing key interactions in the crystalline solid state. The methodology was evaluated with a set of benzodiazepine molecules, using the two-dimensional molecular structure as the only a priori input. The overall trend in intrinsic solubility was correctly predicted for the entire set of benzodiazepines molecules. The results also indicate that, in drug compound series where the melting point is relatively high (i.e., "brick dust" compounds), the reported methodology should be very suitable for identifying strategically important molecular substitutions to improve solubility. As such, this approach could be a useful predictive tool for rational compound design in the early stages of drug development.


Assuntos
Benzodiazepinas/química , Estrutura Molecular , Solubilidade
3.
J Pharm Sci ; 102(7): 2214-20, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23686607

RESUMO

In this paper, we study the thermodynamic and structural changes of crystalline linaprazan (a proton pump inhibitor) upon high-energy ball milling at room temperature. The investigations have been performed by differential scanning calorimetry and powder X-ray diffraction. The results indicate that this drug undergoes a direct crystal-to-glass transformation upon milling. Moreover, upon heating, the amorphous material obtained by milling is shown to recrystallize toward two different polymorphs that appear to form a monotropic set.


Assuntos
Compostos Heterocíclicos com 2 Anéis/química , Inibidores da Bomba de Prótons/química , Varredura Diferencial de Calorimetria , Cristalização , Composição de Medicamentos , Tamanho da Partícula , Transição de Fase , Difração de Pó , Termodinâmica , Difração de Raios X
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA