Surfactants absorption testing effects

Penetration enhancers are low molecular weight compounds that can increase the absorption of poorly absorbed hydrophilic drugs such as peptides and proteins from the nasal, buccal, oral, rectal, and vaginal routes of administration [186], Chelators, bile salts, surfactants, and fatty acids are some examples of penetration enhancers that have been widely tested [186], The precise mechanisms by which these enhancers increase drug penetration are largely unknown. Bile salts, for instance, have been shown to increase the transport of lipophilic cholesterol [187] as well as the pore size of the epithelium [188], indicating enhancement in both transcellular and paracellular transport. Bile salts are known to break down mucus [189], form micelles [190], extract membrane proteins [191], and chelate ions [192], While breakdown of mucus, formation of micelles, and lipid extraction may have contributed predominantly to the bile salt-induced enhancement of transcellular transport, chelation of ions possibly accounts for their effect on the paracellular pathway. In addition to their lack of specificity in enhancing mem-... 

Lipid-based formulations offer a large variety of optional systems. They can be made as solutions, suspensions, emulsions, self-emulsifying systems and microemulsions. Moreover, it is possible to form blends that are composed of several excipients they can be pure triglyceride (TG) oils or blends of different TG, diglyceride (DG) and monoglyceride (MG). In addition, different types of surfactants (lipophilic and hydrophilic) can be added, as well as hydrophilic co-solvents. Lack of enhanced absorption when one of the above key formulations is tested does not necessarily indicate the effectiveness of alternative lipid-based formulations, and their suitability has to be examined. 

The effectiveness of biosurfactants was demonstrated in soil-washing tests using two SOU samples contaminated with PAHs over several decades. Biosurfactants from urban waste compost (cHAL) enhanced PAH desorption from one soil 2-4-fold, relative to SDS. In addition, cHAL showed much less absorption than did SDS (12%-54% vs. 68%-95%). The results indicate that biosurfactants isolated from compost, instead of synthetic surfactants, can be used for soU remediation (Montoneri et af, 2009). 

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