Use of cosmetics by Danish women
acrylic compound such as trimethyl propane trimethacrylate (TPC). This is of considerable significance since TPC may cause allergic contact dermatitis in ultraviolet cured printing inks (Nethercott 1978). Finally, Chung & Giles (1977) showed that guinea pigs could be strongly sensitized to methyl-, ethyland n-butyl methacrylate in ethanol or olive oil by the topical route, or in saline by the intradermal route. For elicitation of skin reactions, topical challenge with the compounds in olive oil or intradermal challenge with saline as the solvent was necessary. All sensitized animals responded strongly not only to the inducting methacrylate but also to the other methacrylates, showing that mutual cross-sensitivity had occurred. They concluded by stating that, "Since methyl methacrylate has been reported to be a potent sensitizer in humans, the guinea pig model described here may be useful for screening products before marketing."
Butyl methacrylate monomer and ethyl methacrylate monomer – frequency of reaction
In the United States, artificial nail products containing methyl methacrylate monomer caused sufficient consumer complaints (involving onycholysis, nail discoloration and/or irritation) to necessitate regulatory action by the Food and Drug Administration (U.S. District Count Decision 1974). Similar experiences occurred in Great Britain (Cronin 1976). It is alleged that butyl methacrylate monomer and ethyl methacrylate monomer are contained in these products in the U.S. at this time. To determine frequency of reactions and appropriate patch test concentration, the following study was performed. Eight centers were involved. Fresh samples of commercial grade ethyl methacrylate and n-butyl methacrylate monomer were tested with Al-Test® (Imeco Agency, Sweden) or the Finn Chamber on the back for 48 h. Readings were according to the ICDRG scale (usually at 48 and 96 h). The concentration was 1 % petrolatum. Of 542 dermatitis patients tested, one patient reacted to ethyl methacrylate and one to ethyl and butyl methacrylate. Both patients were believed to have allergic type reactions; both were considered possibly to be of past relevance because of history of dermatitis with use of acrylate paints. Four patients were methyl methacrylate monomer-sensitive (to 1 % in petrolatum); none cross reacted to the ethyl and butyl acrylate monomers. This was a special group of four patients having histories suggestive of acrylic sensitization and so were tested to this monomer. Active sensitization was not observed. Previous experience led Cronin & Calnan (unpublished data) to discontinue the use of 5 % butyl acrylate in patch testing because of active sensitization. In conclusion, 1 % n-butyl methacrylate monomer and 1 % ethyl methacrylate monomer appear safe concentrations for patch testing. These will have to be tested in enough clinically sensitive patients to verify that false negative responses will not occur. These nbutyl and ethyl methacrylate monomers did not cross react in four methyl methacrylate monomer subjects.
One-pot synthesis of annulated pyrido[2,3-d:6,5-d]dipyrimidine derivatives using nitrogen based DBU catalyst in aqueous ethanol medium
Abstract We have reported DBU as an efficient organocatalyst for one-pot three-component synthesis of annulated pyrido[2,3- d :6,5- d ]dipyrimidine derivatives using aromatic aldehyde, thio-barbituric acid and 6-amino-uracil in aqueous ethanol under reflux. The attractive advantages of this process are mild reaction conditions, environment friendly procedure, short reaction times, easy isolation of products, and excellent yields (72–89%).