RESUMEN
Tapioca starch (TS) is produced from Cassaca roots and it is differentiated from other starches because it contains about 17-20% amylase and low amount of residual substances. Propranolol (POP) is a non-selective beta-adrenergic blocking agent and it is in the World Health Organization's List of Essential Medicines. The aim of this work was to investigate the potential of TS in the development of POP tablets by means of direct compression. Its evaluation was performed by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Nuclear Magnetic Resonance (NMR) relaxometry, scanning electron microscopy (SEM), uniformity of weight, drug content, disintegration, friability, hardness, dissolution test and drug release kinetics. The TS granules were spherical with mean diameter of 10.09 ± 1.85 µm. The XRD, FTIR and NMR suggested physical interaction between TS and POP. The tablets presented average diameter of 1.1 ± 0.0 cm, 0.24 ± 0.02 cm thickness and average weight of 0.544 ± 0.003 g. The hardness of tablets was 10.98 ± 0.31 N and the percentage of friability was 25.74 ± 0.08%. POP was released after 45 min and the release kinetics properly fitted the Hixson-Crowell equation.
Asunto(s)
Antagonistas Adrenérgicos beta/química , Excipientes/química , Manihot/química , Propranolol/química , Almidón/química , Comprimidos/química , Diseño de Fármacos , Pruebas de Dureza , Espectroscopía de Resonancia Magnética , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Tamaño de la Partícula , Valores de Referencia , Reproducibilidad de los Resultados , Espectroscopía Infrarroja por Transformada de Fourier , Factores de Tiempo , Difracción de Rayos XRESUMEN
The aim of this work was to investigate the starch degradation of bananas stored at low temperature (13°C, cold-stored group) and bananas stored at 19°C (control group) during ripening. The starch granules were isolated during different stages of banana ripening, and their structure was investigated using different techniques. The activities of α-amylase and ß-amylase associated to the starch granules were determined, and their presence was confirmed using immunolocalization assays. The increased molecular mobility likely facilitated the intake and action of α-amylase on the granule surface, where it was the prevalent enzyme in bananas stored at low temperature. The 10 days of storage at low temperature also influenced the sizes and shapes of the granules, with a predominance of rounded granules and pits on the surface along with superior amylose content, the higher amounts of amylopectin A-chains and the subtle increase in the A-type allomorph content.
