Encapsulating agents

Presently, several clinical trials with liposome-encapsulated agents are under way and more are planned (Zonneveld and Crommelin, 1988 Klausner, 1988). During the last 5 years, key issues related to the pharmaceutical manufacturing of liposomes such as stability, sterilization, upscaling, and reproducibility have been successfully addressed. Although it is generally believed that a proper selection of the bi-layer components can minimize the occurrence of toxic effects due to the use of natural body constituents, the issue of liposome-related toxicity is not a trivial one and should be carefully studied,... 

Hirano, K., and Hunt, C. A. (1985). Lymphatic transport of liposome-encapsulated agents Effects of liposome size following intraperitoneal administration, J. Pharm. Sci., 74, 915-921. 

The liquid composition of niclosamide and a nonaqueous liquid carrier in an encapsulating agent was investigated [13]. 

Silicone resins find use as insulating varnishes, impregnating and encapsulating agents and in industrial paints. 

Adjuvants (density adjustment for flavouring oils in beverages, diluent for colours and other food additives, encapsulating agent, excipient) Adsorbants (decolourizing agent)... 

Encapsulation and drying of flavors are dependent on the performance of encapsulating agents. These agents should ... 

The use of Acacia gum as an encapsulation agent is governed by the same principles as the preparation of a stable liquid emulsion. 

In order to provide these functions the encapsulating agent should have the following properties ... 

Gum arable has been the encapsulating agent of choice for many years. Gum arable has all the properties mentioned above which has helped expand its use in the Food Industry. 

King, W., Trubiano, P., and Perry, P., Modified Starch Encapsulating Agents Offer Superior Emulsification, Film Forming and Low Surface Oil, Food Prod. Dev., 10, 54, 1976. 

Operating temperatures on shelf-life, while eliminating the effect of other variables (such as encapsulating agent, solids concentration, and powder moisture content) on shelf-life. 

Recently,it was reported that when maltodextrins were used as the encapsulating agent, increasing the dextrose equivalent by 10 could result in a three to six fold enhancement in shelf life (5). The reduction in emulsion size of feed emulsion also improved the shelf stability (Risch, S. J., University of Minnesota, personal communication, 1986). However, the influence of particle size distribution on the stability of encapsulated flavors has not been clearly addressed in the literature. 

Spray Drying of Orange Oil. Capsul, a modified food starch (National Starch and Chemical Corp., Bridgewater, NJ), was used as the encapsulation agent. Capsul solution with 30 (w/w)solids content in deionized water was prepared. Orange oil (Florida Valencia), 20 (w/w) of solids, was emulsified into... 

There are a wide variety of encapsulating agents available on the market. Modified food starches, maltodextrins, gums, proteins, corn syrups and sugars are popular choices (4-7). The selection of an encapsulating agent depends upon the chemical composition of the flavor, the encapsulation method, the desired properties of the final microcapsule and its end uses. Other considerations include cost and availability. 

The stability of orange peel oil depends on the selection of the encapsulation process and the encapsulating agent. The results of this study indicated that the differences in shelf life were greatly accentuated at higher temperatures. The shelf life of the spray dried products ranged from 5-35 days compared to the extrusion and beta-cyclodextrin products which were still acceptable after 180 days at 50 C. 

Bioerodible poly(ortho ester) copolymers containing hydrophilic and hydrophobic blocks have been prepared from di(ketene acetals) and oligomeric diols. These materials form micelles in aqueous solution making them useful as hydrophobic encapsulation agents or as bioerodible matrices for the sustained release of medicaments. 

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