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In the present study, taste masked drug–resin complex (DRC) of efavirenz (EFV) was prepared by spray drying technique. The DRC was then incorporated in to a fast dissolving tablet dosage form. EFV is antiretroviral agent of very bitter taste and low oral bioavailability. To investigate the influence of the independent variables on encapsulation efficiency (EE) as well as on the bitter taste of EFV, response surface methodology was employed. Ion-exchange resin (tulsion-335) and amount of solvent were selected as the independent variables while the EE was selected as the dependent variable. DRC was characterized for EE, X-ray diffraction, particle size distribution, Fourier transform infrared spectroscopy, surface morphology, and in vitro dissolution study. The spectrophotometric method was used for the evaluation of bitter taste of EFV. The EE was found to be 37–84%. The compressed tablets were evaluated for the hardness, Friability, wetting time, disintegration time and in vitro drug release studies. This study confirmed that complexation of the drug with an ion-exchange resin can effectively mask the bitter taste of the drug in combination with production of fast dissolving tablets. [ABSTRACT FROM AUTHOR]

The antifungal activity of chitosan was tested in vitro against Alternaria alternata and Geotrichum candidum, two major post-harvest pathogens of tomato. Chitosan, at all concentrations, inhibited spore germination in A. alternata and G. candidum. Survival of the yeast biocontrol agent, Candida utilis, in chitosan solution was also studied in vitro, as well as in fruit wounds. Chitosan did not adversely affect the growth of C. utilis. In fruit wounds, populations of C. utilis with or without chitosan increased to the target level (107 CFU per wound) within 7 d, and thereafter became stable. In in vitro studies, populations of C. utilis increased in 0.25% (w/v) chitosan solution; while in 0.5% (w/v) and 1% (w/v) solutions, populations dropped initially, but resumed growth within 24 h. The addition of 0.25% (w/v) chitosan solution to a cell suspension of C. utilis significantly enhanced its efficacy in controlling post-harvest decay of tomato compared with treatments of C. utilis, or 0.25% (w/v) or 0.5% (w/v) chitosan alone. The efficacy of a combination of C. utilis and chitosan was not increased by increasing the concentration of chitosan from 0.25% (w/v) to 0.5% (w/v). [ABSTRACT FROM AUTHOR]