Glycerol–Silicone Membranes for Sustained and Controlled Topical Delivery of Antimicrobial and Pain‐Relief Drugs

Abstract

Controlling drug delivery from medical dressings to wounds remains a challenge despite the presence of multiple drug‐containing wound dressings on the market. The dressing should ideally be effective immediately after application and still show no burst effect, and must also be comfortable for an extended period of time. Here, a silicone‐based membrane is shown to offer an adjustable, constant release of various drugs even at a minimum moisture level resembling that of dry wounds. The drugs are dissolved in glycerol, which is speed‐mixed with silicone and subsequently cured to yield a solid membrane with evenly distributed glycerol microcontainers housing the drug. The drugs are released immediately upon contact with moisture, enabling efficient treatment with short response time and no burst. Drug delivery capability is evaluated using a classical drug release experiment, as well as by performing an antimicrobial susceptibility test on ten bacterial strains in agar diffusion assays. Results show that glycerol–silicone membranes are promising candidates for fighting bacterial infections. Moreover, the addition of glycerol domains to a silicone matrix is proven to have a positive impact on water vapor transmission rate and moisture handling capabilities, resulting in a more skin compliant dressing.

Simultaneous delivery of several antimicrobial drugs from multi‐compartment glycerol‐silicone membranes

“…The antimicrobial susceptibility assay was carried out as previously described. 50 Eight bacterial species (represented by a total of 10 strains) that are commonly found on the human skin and/or in acute and chronic wounds were investigated. The GSE membranes were placed onto the agar, and the plates incubated at 35 C for 18-20 h. Subsequently, the diameters of the growth-inhibition zones were measured.…”

“…The results of an antimicrobial study published recently confirmed that the GSE membranes containing TCS are effective against a variety of bacterial strains. 50 Importantly, the membranes performed substantially better when compared to two state-of-the-art commercially available antimicrobial wound dressings. Here, we investigate the antimicrobial action of the GSE membranes loaded with TET and MUP.…”

“…Moreover, it has been established that the drug concentration does not influence the percentage release rate while the increasing membrane thickness decelerates the release rate but does not determine the ultimate degree of substance release. 48,50 In the present study, UV-vis spectrophotometry was used to investigate the simultaneous release of hydroquinone (absorbance maximum at 290 nm) and erythrosine B (absorbance maximum at 526 nm) from a dual-compartment GSE membrane. The substances were selected based on their distinct UV-vis spectra, which made the data analysis possible.…”

“…It is anticipated that the release rates from the multi-compartment GSEs will exhibit more similarities to the singlecompartments GSEs, such as control of the release rates via adjustment of the membrane thickness and/or drug concentration in glycerol. 48,50 3.4 | Antimicrobial activity of single-, dual-, and triple-compartment GSE membranes…”

“…Release profiles of individual drugs were studied previously. 50 Each specimen contained 80 phr of glycerol and the total drug content per sample (6 mm diameter and 0.3 mm thickness) was 42 μg. GSEs without any drug as well as pure silicone membranes were used as controls and they did not show any antimicrobial activity.…”