Preservatives synergy

EDTA Chelates alkaline earth and heavy metals 0.005-0.01% w/v antimicrobial activity synergy Often used in combination with other antimicrobial preservatives, and other antioxidants based on their synergy... 

The use of multiple preservatives in a liquid formulation can be extremely advantageous. Individual preservatives are able to interact synergistically or antagonistically with one another. Synergy in combination preservative systems is thought to occur by inhibition of preservative inactivation, increasing... 

Fig. 4 Isobologram showing three possible outcomes of interaction between preservatives A and B, namely (A) antagonism (B) additivity and (C) synergy.

Denyer SP, Hugo WB, Harding VD. Synergy in preservative combinations. Int Pharm 1985 25 245-253. 

Ascorbic acid was used to prevent the oxidation of olive oil, milk, arachis nut oil, lard, ethyl ester of lard, cottonseed oil, pork, and beef fat (4) data showing activity alone and as a synergist are reviewed. Ascorbyl laurate, myristate, palmitate, and stearate were similarly active, although only AP is listed as a preservative in GFR. Ascorbic acid synergy with tocopherol was also reviewed. 

The role of cytokines in anti-CD3-mAb-mediated nephropathy was analyzed by pretreating mice with either neutralizing anti-TNF antibodies or mPDS [156]. The histologic lesions and the renal excretion of endopeptidase 24.11 were moderately prevented by anti-TNF antibodies, suggesting the involvement of other mediators, which could act in synergy with TNF-a. In support of this view, steroid pretreatment before anti-CD3 challenge almost completely abohshed IL-2, TNF-a and IL6 release and resulted in preservation of renal histology. 

In addition to the simple case in which the effect of a mixed catalyst increases because its components give a new chemical compound, various other mechanisms for this increase are possible. Here we shall consider the following ones (1) both components affect the reacting molecule jointly, more often at the interface of solid phases formed by these components (the case of synergy) (2) only one component acts, the other preserves the activity of the former, for example, protects it from sintering, etc. 

Orth, D. S., Anderson Lutes, C. M., Smith, D. K., Milstein, S. R., 1989. Synergism of preservative system components Use of the survival curve slope method to demonstrate anti Pseudomonas synergy of methylparaben and acryUc add homopolymer/copolymers in vitro. J. Soc. Cosmet. Chem. 40, pp. 347 365. 

Photochromic organic-inorganic hybrid materials are one of the most studied systems. It is believed that the synergy of organic and inorganic compounds in hybrid materials can preserve or even improve the features of the components. Nowadays, it has been demonstrated that hybrid systems can also confer the material new properties, different from those of the single components [6,10]. 

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