Encapsulation of drugs and active ingredients

Drug delivery systems have been developed for doxorubicin [51] (a drug used to treat leukemia but which has cardiac risk factors), and for flavors such as decanoic acid [52]. In both cases, the encapsulation efficiency as given by load, recovery speed and recovered quantity was assessed. In addition, the stabihty (shelf life) of such gel matrices in terms of stabihty of the pharmaceutically active ingredient was increased compared to their free form. Similar appHcations for coatings for the controlled release of biocides [53] and other pharmaceuticals such as vitamins [54] have also been made. Clearly, gel porosity, pore size distribution, temperature, pH all influence the release, and these parameters must be optimized. 

Select the active ingredient (AI) or drug/pesticide product and the microcapsule encapsulating it by evaluating the controlled release of the AI [Muro-Sune et al. (2005)] through the microcapsule. 

Oral Delivery Amphiphilic P-CD nanocapsules loaded with indomethacin have been evaluated in vivo. The nanocapsules have been applied to the rat model. It was reported that the gastrointestinal mucosa of the rat was significantly protected from the ulcerogenic effects of the active ingredient indomethacin in free form. Drug encapsulation yield in the nanocapsules were >98% and the drug content per CD unit was 7.5% w/w [89],... 

Encapsulation is a process in which tiny particles or droplets are covered by a coating [36-43]. Its role is either to isolate the active ingredient or to control the rate by which it leaves the capsule. As examples for the first case, one can mention the isolation of vitamins from oxygen or of a reactive core from chemical attack, and for the second case, the control of the rate of release of drugs or pesticides. Numerous encapsulation techniques have been suggested. Most of the encapsulations of the active solid materials have been carried out for solids larger than 1 pm. 

Liposomes have been used for years as components of drug delivery systems, and as transdermal carriers of active ingredients in the cosmetic industry (307, 308). More recently, liposomes have found use in the food and nutritional supplement industries. Keller (308) lists more than a dozen nutritional products on the market that have been formulated with novel liposome-based delivery systems. In the food area, hposomes have been studied for their ability to encapsulate and provide controlled release of enzymes (309, 310), and liposome-encapsulated enzymes have been used to accelerate the ripening of cheese (311). 

The phase contained in the subdrops is often referred to as the encapsulated phase. These systems are very relevant to transport phenomena and separation processes (14), such as controlled release of drugs in which the encapsulated phase can serve as a reservoir of the active ingredient. 

Bioencapsulation is a technology, being used since three decades, which uses bioactive molecules to be inserted and immobilized on specific supports (matrices). Encapsulation technology is now well developed and accepted within the pharmaceutical, chemical, cosmetic, foods, and printing industries. The encapsulation of active components has become very attractive being adequate for food ingredients as well as for chanicals, drugs, or cosmetics to be released in a controlled way. 

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