Controlled release mechanism

While in ancient times, the sensorial properties of a flavour for foodstuffs were of major importance, modern flavours have to perform like multifunctional systems. Physical form, chemical and mechanical stability and controlled release mechanisms are meanwhile essential criteria for the flavour quality. All these properties have to be addressed by a flavourist in close cooperation with technologists. Therefore, knowledge about food product properties must lead to a careful and intelligent evaluation of the flavour system as an important driver for the success of the final product. 

R.W. Baker and H.K. Lonsdale, Controlled Release Mechanisms and Rates, in Controlled Release of Biological Active Agents, A.C. Tanquary and R.E. Lacey (eds), Plenum Press, New York, pp. 15-72 (1974). 

Despite the long list of requirements, a variety of chemical fmishes have been used to produce textiles with demonstrable antimicrobial properties. These products can be divided into two types based on the mode of attack on microbes. One type consists of chemicals that can be considered to operate by a controlled-release mechanism. The antimicrobial is slowly released from a reservoir either on the fabric surface or in the interior of the fibre. This Teaching type of antimicrobial can be very effective against microbes on the fibre surface or in the surrounding enviromnent. However, eventually the reservoir will be depleted and the finish will no longer be effective. In addition, the antimicrobial that is released to the enviromnent may interfere with other desirable microbes, such as those present in waste treatment facilities. 

Formulation is a common method of developing sustained release preparations such as erosion tablets, drugs in a waxy matrix (matrix erodes or drug leaches from matrix), coated pellets (different pellets have different release properties), and coated ion-exchange preparations. There are special considerations for sustained release systems, since complicated formulations may be more erratically absorbed the sustained release product may contain a larger dose (and failure of the controlled release mechanism may result in release of a large toxic dose) and is a more expensive technology. 

Baker RW, Lonsdale HK. Controlled release mechanisms and rates. In TanquaryAC, RE Lacy, eds. Controlled Release of Biologically Active Agents. New York Plenum Press, 1974 15-71. 

Baker, R.W. Lonsdale, H.K. "Controlled Release Mechanisms and Rates" in Controlled Release of Biologically Active Agents, Vol. 47 of Advances in Experimental Biology and Medicine, A.C. Tanquary R.E. Lacey, Eds. Plenum Press,... 

Extended drug action through the use of special controlled release mechanisms... 

In summary, it appears that the incorporation of IBA into a polymer has a positive effect on the rooting of Albo Lacinatus. Activity of the polymeric materials is probably through a controlled release mechanism. 

Polymer Controlled release mechanism Special notes... 

Conversely, it can be argued that the filler surface can be also be used as a reservoir of stabiliser, provided it can be released from the surface in a controlled manner. Liauw and co-workers have examined the effect of incorporation of gel silica (323 m g ) at 0.1% w/w, on the thermal stabilisation (melt and solid state) and UV stabilisation of linear low density polyethylene [16, 17]. The adsorption characteristics of all the stabilisers investigated were examined by FMC [17] and heat stabiliser/UV stabiliser combinations were devised on the basis of relative strength of adsorption. The stabilisation performance was found to be enhanced in the presence of silica only when the more active stabiliser was weakly adsorbed relative to the less active one this indicated a controlled release mechanism that was associated with displacement of the weakly adsorbing stabiliser... 

Although parenteral preparations of oxycodone exist, in the USA oral formulations only are available. Controlled-release forms must be swallowed whole so as not to interfere with the controlled-release mechanism chewing or cutting may lead to an overdose. Available oxycodone preparations are listed in Table 19.1. 

Organotin-based antifouling have been technically the most successful product for years. They owe this success to a unique mechanism to prevent fouling. They combine the toxic properties of TBT (tributyltin) with a controlled-release mechanism, which guarantee constant activity up to 5 years (coating thickness is the limitation). 

Matrix bound coumaphos and trichlorfon and encapsulated toxicants containing ethyl and methyl pirimiphos, permethrin, and diazinon were found to be ineffective against the fire ant. However, the ineffectiveness was not due to the controlled release mechanism but rather the ability of the ant to filter particles in its infrabuccal pocket in its head. Particles as small as 0.88 microns can be filtered and never come in contact with internal parts. 

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