Synergistic effect of miscible cellulose-based microparticles and pH modulators on the bioavailability of a weakly basic drug and its metabolites.

This study aimed to evaluate the miscibility of cellulose derivatives to improve the release rate and stability of microparticles containing the weakly basic drug itraconazole (ITZ). We also investigated the effect of some organic acids on the microenvironmental pH (pHm) and the release rate of ITZ from the cellulose-based microparticles. The synergistic effect of cellulose-based microparticles and pHm modulators on the bioavailability of ITZ compared with the reference product was investigated in a rabbit model. Differential scanning calorimetry and Fourier-transform infrared spectroscopy (FTIR) analysis showed that ITZ, hydroxypropyl methylcellulose, and hydroxypropyl methylcellulose phthalate were miscible at a ratio of 1.5:3:1 (w/w/w), and the stability of the microparticles was maintained for 6 months under accelerated conditions. In addition, X-ray diffraction, FTIR, and scanning electron microscopy were used to characterize the properties of the microparticles. Through the titration technique and determination of pHm, the combination of fumaric acid and maleic acid (1:2, w/w) was found to be the most effective pHm modulator for microparticles. The integration of cellulose-based microparticles and pHm modulators showed a synergistic effect on the flux and relative bioavailability of ITZ and its active metabolite OH-ITZ (182.60 % and 217.67 %, respectively) when compared with the reference product.

Study on infected degree of species of Aspergillus flavus and aflatoxin on lotus seed at some localities in Ha Noi

Contamination by Aspergillus flavus and aflatoxin B1 of 20 samples of lotus seed collected at Ha Noi was investigated. The results showed that 100% of samples were contaminated with Aspergillus flavus, the mean contamination rate with Aspergillus flavus was 40%. 4/20 samples was contaminated with aflatoxin B1, the mean contamination amount was 165 ppb, ranged from 17,5 ppb to 434 ppb. The samples were contaminated with aflatoxin B1 as high as A.flavus. The samples of lotus seed collected from traditional medicine shops had the contamination by A.flavus and aflatoxin B1 higher than that taken from the markets