Permeation of pharmaceutical compounds through silicone membrane in the presence of surfactants

Abstract

This study reports the effect of surfactant charge and concentration on the permeation of four model compounds (benzocaine, benzotriazole, ibuprofen and lidocaine). Surfactant charge was systematically varied using a range of surfactants that are known to possess specific head group charges, namely an anionic, a cationic, a zwitterionic and a neutral form over a series of surfactant concentrations, i.e. where possible, both above, and below, the critical micellar concentration for each surfactant. It was found that there was almost always a systematic reduction in permeation as the concentration of surfactant increased despite the wide range of physicochemical properties exhibited by the four model compounds studied. Overall, it was concluded that the presence of surfactant does generally seem to reduce permeation, regardless of the compound in question, and that the effect is surfactant concentration, as well as charge, dependent.

Fabrication of Alginate-Based O/W Nanoemulsions for Transdermal Drug Delivery of Lidocaine: Influence of the Oil Phase and Surfactant

“…At the higher oil concentration, again flux improves with initial increase in surfactant concentration and then reduces with further increase in surfactant concentration. These results further prove that the increase of surfactant concentration over a specific limit retards the permeation of lidocaine as presented in literature [ 52 , 60 ]. These observations confirmed the benefit of PDMS membrane in screening the formulation variables before testing on the skin.…”

“…At higher surfactant concentration, however, flux became higher which will be discussed later. On another note, the maximum amount that was able to permeate through the membrane after 6 h was found to be 394.04 µg/cm 2 , whereas in this study reached higher than 1000 µg/cm 2 [ 52 ]. Waters et al also showed similar results in which the highest flux value obtained was 118.4 µg/h/cm 2 which is similar to those obtained in this study.…”

“…The permeation of lidocaine from all nanoemulsions is presented in Figure 5 , which shows the cumulative amount of lidocaine that permeates across PDMS membrane as a function of time over a period of 22 h. Although, PDMS membrane often provides good correlation with an in vivo situation, it is considered to offer a rather simplified skin model. This seems to be advantageous while demonstrating formulation screening and drug permeability, as this synthetic membrane produces reproducible results, reduces cost and eliminates any ethical issues as compared with natural skin [ 52 ]. Yet, there are certain disadvantages to the use of PDMS; for example multiple factors could affect the permeation such as ionization whereby permeation is more favorable for the more unionized form of a compound [ 53 ].…”

“…As given in Table 1 , the flux values of lidocaine vary in some cases with different surfactant concentration, oil concentrations and oil type. This change could be attributed to the interactions between either the surfactant and membrane or the drug and surfactant [ 52 ].…”

Permeation of Pharmaceutical Compounds Through Silanized Poly(dimethylsiloxane)

“…Examples include mathematical models (Mitragotri et al, 2011), human skin equivalents (Schmook et al, 2001) and chromatographic based methods (Waters et al, 2013b), a summary of the main proposed methods can be found in (L Waters, 2015). A reliable membrane to employ as a skin mimic is poly(dimethylsiloxane), also known as PDMS, which has been the focus of several research groups in recent years (Bhuiyan and Waters, 2017;Luo et al, 2016;Rodríguez-López et al, 2019;Shahzad et al, 2014;Waters and Bhuiyan, 2016;Waters et al, 2013a;Watkinson et al, 2009). PDMS has a silicon-oxygen backbone with a very high bond energy providing high thermal stability, i.e.…”