RESUMEN
Abstract Hydralazine hydrochloride is an anti-hypertensive drug. The drug has poor oral bioavailability (BA) of about 30- 50% due to extensive first-pass metabolism. Hence, the buccal delivery was used to enhance the BA of hydralazine hydrochloride. Buccal muco-adhesive tablets were prepared by direct compression technique, using carbopol 934P, HPMC K4M, sodium alginate and sodium carboxy methyl cellulose (NaCMC) as muco-adhesive polymers. Prepared formulations were evaluated for physico-chemical characterization, ex-vivo residence time and in-vitro release studies. The some of the parameters viz hardness, thickness, weight variation are showing the values within the pharmacopeial limits. However, the swelling and bio-adhesive strength were increased with increasing polymer concentrations. From the in-vitro release studies, F9 buccal tablets prepared with NaCMC exhibited better release (96.56%, 6 h) profile than all other formulations and considerd as optimized. The release mechanism from kinetic methods suggests that, the drug release follows zero-order kinetics with diffusion mechanism. Thus, the buccal tablets of hydralazine hydrochloride showed enhanced BA and were further confirmed by in-vivo studies.
RESUMEN
Research on causal relations in multisemiotic texts constituted by words and graphs has been scarce with only a few exceptions. In the current study, eye movement behavior was studied in seventy-six Chilean high school students, who read a set of twelve causally-related economics texts in Spanish in four experimental conditions. The objective is twofold. We aimed, on the one hand, to observe the main effects of the causal discourse marker (DM) por tanto and the statistical causal graph (G), as well as the interaction effect of both variables on different eye tracking measures. On the other, we seek to observe the effects of the DM on the same eye tracking measures for the graph system (GS) area of interest (AOI). The findings showed that the conjoint presence of the DM and the G did not positively influence the processing of selected AOIs. Analyses also reveal no significant effects on the GS AOI. Thus, the results indicate that the DM tend to decrease processing times, while the G increases them. Additional analyses conducted on the integrative transitions between the verbal system and the graph system reveal that more transitions were identified between the consequence segment and the graph system, thereby confirming that the consequence segment is crucial for the integration of both semiotic systems.