Home About us Contact
|
Home About us Contact | ||
|
|
||
Shell Design (shell + design)
Selected AbstractsImprovement of the in vitro Digestible Iron and Zinc Content of Okra (Hibiscus esculentus L.) Sauce Widely Consumed in Sahelian AfricaJOURNAL OF FOOD SCIENCE, Issue 2 2007Sylvie Avallone ABSTRACT:, The effects of the formulation (okra, fish, soumbala, extract of wood ash) and cooking time of okra sauce on total iron and zinc content and on their in vitro digestibility were evaluated following a Doehlert uniform shell design with 5 factors and 33 trials. Cooking time had no significant effect on in vitro digestible iron and zinc content, whereas formulation did. Each ingredient had a specific effect. Extract of wood ash, which is a source of soluble and digestible iron and zinc, is a good way of increasing the digestible mineral content of the dish. Okra, the main ingredient in this sauce, has a negative effect and should be added in moderate quantities (< 37.7% of the DM of the sauce). An optimization using the desirability function allows us to identify the optimal recipe that enabled the quantity of digestible iron to be doubled and the quantity of digestible zinc to be increased by one third. This recipe calls for a mixture of 37.7% okra, 26.3% dried fish, 18.5% soumbala, and 3.7% extract of wood ash cooked for 25 min. [source] Physicochemical characterization of papain entrapped in ionotropically cross-linked kappa-carrageenan gel beads for stability improvement using Doehlert shell designJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 9 2006Mayur G. Sankalia Abstract This work examines the influence of various process parameters on papain entrapped in cross-linked ,-carrageenan beads for improvement of its stability. A Doehlert shell design (DSD) was employed to investigate the effect of three process variables, namely ,-carrageenan concentration, KCl concentration, and hardening time, on the entrapment, time required for 50% enzyme release (T50), time required for 90% enzyme release (T90), and particle size. The beads were prepared by dropping the ,-carrageenan containing papain into a magnetically stirred KCl solution. Topographical characterization was carried out by scanning electron microscopy and entrapment was confirmed by Fourier transform infrared spectroscopy and differential scanning calorimetry. Stability testing was carried out according to the International Conference on Harmonization (ICH) guidelines for zone III and IV. A polymeric matrix was prepared with ,-carrageenan (3.5% w/v) and potassium chloride (0.5 M) using the ionotropic gelation method, with a hardening time of 20 min. Beads characterized by a spherical disc shape with a collapsed center, an absence of aggregates, an entrapment of 82.75%, a T90 value of 55.36 min, and a composite index of 88.55 were produced. The shelf-life of the enzyme-loaded beads was found to increase to 3.63 years compared with 1.01 years for the conventional formulation. It can be inferred that the proposed methodology can be used to prepare papain-loaded ,-carrageenan beads for stability improvement. © 2006 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 95: 1994,2013, 2006 [source] Optimization of a novel headspace,solid-phase microextraction,gas chromatographic method by means of a Doehlert uniform shell design for the analysis of trace level ethylene oxide residuals in sterilized medical devicesBIOMEDICAL CHROMATOGRAPHY, Issue 6 2009Michael P. DiCicco Abstract Medical devices sterilized by ethylene oxide (EtO) retain trace quantities of EtO residuals, which may irritate patients' tissue. Reliably quantifying trace level EtO residuals in small medical devices requires an extremely sensitive analytical method. In this research, a Doehlert uniform shell design was utilized in obtaining a response surface to optimize a novel headspace,solid-phase microextraction,gas chromatographic (HS-SPME-GC) method developed for analyzing trace levels of EtO residuals in sterilized medical devices, by evaluating sterilized, polymer-coated, drug-eluting cardiovascular stents. The effects of four independent experimental variables (HS-SPME desorption time, extraction temperature, GC inlet temperature and extraction time) on GC peak area response of EtO were investigated simultaneously and the most influential experimental variables determined were extraction temperature and GC inlet temperature, with the fitted model showing no evidence of lack-of-fit. The optimized HS-SPME-GC method demonstrated overall good linearity/linear range, accuracy, repeatability, reproducibility, absolute recovery and high sensitivity. This novel method was successfully applied to analysis of trace levels of EtO residuals in sterilized/aerated cardiovascular stents of various lengths and internal diameter, where, upon heating, trace EtO residuals fully volatilized into HS for extraction, thereby nullifying matrix effects. As an alternative, this novel HS-SPME-GC method can offer higher sensitivity compared with conventional headspace analyzer-based sampling. Copyright © 2009 John Wiley & Sons, Ltd. [source] | ||||||||||