Influence of Micelles on the Basic Degradation of Carbofuran

Abstract

The effect of micellar aggregates upon the stability of carbofuran in basic media has been studied. The effect of the presence of micelles upon the basic hydrolysis of carbofuran is a function of the nature of the surfactant monomer. Important catalysis of basic hydrolysis of carbofuran in the presence of colloid aggregates with positive surface charge has been reported. On the other hand, the presence of anionic and nonionic surfactants implies a large inhibition of the basic hydrolysis of carbofuran. Both catalysis and inhibition are due to the association of carbofuran with the micellar core. The kinetic constants for the basic hydrolysis of carbofuran in these microheterogeneous media have been obtained on the basis of a micellar pseudophase model. No significant changes in the intrinsic reactivity of HO- against carbofuran have been observed.

Acid Hydrolysis of Bromazepam Catalyzed by Micelles, Reverse Micelles, and Microemulsions

“…Cationic micelles enhanced the rate of alkaline hydrolysis of acetylsalicylic acid and trifusal at low surfactant concentrations, although inhibited the reactions at high surfactant concentrations, while anionic micelles show a catalytic effect and zwitterionic and nonionic micelles show inhibitory effect at all concentrations [34]. The basic hydrolysis of carbofuran was catalyzed in the presence of colloidal aggregates with positive surface charge and large inhibition by anionic and nonionic surfactants [35].…”

“…Research to date includes numerous attempts to explore the catalysis of hydrolysis reactions by supramolecular selfassembled systems such as micelles, reverse micelles, and microemulsions using a wide variety of substrates, including esters [11,12], dyes [13][14][15][16][17][18][19][20], and drugs [11,[21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]. Bromazepam (Bz) is used as a psychotropic drug which undergoes acid/base hydrolysis in aqueous solution and study of this reaction, within the physiological pH range, is of great importance because the absorption of these drugs in the gastrointestinal tract is affected by the nature of the chemical species involved.…”

Microwave-Assisted Extraction of Methyl β-Cyclodextrin-Complexed Curcumin from Turmeric Rhizome Oleoresin

“…Therefore, solubility tends to increase with increasing temperature and is suitable for pharmaceutical applications. Arias et al (2005) studied the influence of micelles on the basic degradation of carbofuran and discovered that both anionic and nonionic surfactants inhibit the decomposition of carbofuran. The presence of cationic surfactant catalyzes the decomposition of carbofuran.…”

Influence of colloid suspensions of humic acids on the alkaline hydrolysis of N‐methyl‐N‐nitroso‐p‐toluene sulfonamide

“…The velocity of different reactions could be influenced by the presence of HSs [11,12,[14][15][16][17][18][19]. Reactions of interest would be related to hydroxyl ion attack, much studied to evaluate micellar catalysis [20,21]. In fact, it is well known that hydrolysis processes are among the major transformation pathways for numerous xenobiotics such as pesticides or pharmaceuticals in the environment [19][20][21].…”