Biomedical Silicone Elastomers as Carriers for Controlled Release

Abstract

Biomedical silicone elastomers have been studied for their potential application as carriers for controlled release of drugs, since these materials display a unique combination of properties, which might be favorable to the above use. A two component silicone gel system was used and various cross-linker ratio was applied, in order to produce networks with varying crosslink density. Swelling experiments in toluene were run in order to evaluate the network characteristics. The silicone elastomer was loaded with salicylic acid and propranolol hydrochloride and their delivery in distilled water was followed. The results showed that release is almost of zero order for high loading of salicylic acid, while delivery seems to be diffusion controlled up to a certain limit. The administered drug concentrations are relatively low if silicone discs are used, due to the hydrophobic nature of this material. On the other hand, when membranes are used with a thickness of 0.1-0.2 mm, then the delivery rate is much higher depending of course on the hydrophilic character of the drug.

Docetaxel epimerization in silicone films: a case of drug excipient incompatibility

“…[6] Crosslinking is based on different chemistries involving free radicals and organometallic catalysts. Curing involves crosslinking of the polymeric chains to form a three-dimensional polymeric network.…”

“…Curing involves crosslinking of the polymeric chains to form a three-dimensional polymeric network. [6] Crosslinking is based on different chemistries involving free radicals and organometallic catalysts. [7] In the current study, silicone films were investigated for controlled delivery of docetaxel (DTX) using a commercially available three-part (A, B, and C) silicone kit, DDU-4340 (Nusil Technology LLC, Carpinteria, CA, USA) based on condensation chemistry.…”

Comparative study of the release kinetics of osmotically active solutes from hydrophobic elastomeric matrices combined with the characterization of the depleted matrices

“…[1][2][3][4][5] In these cases, the release takes place by the diffusion of the drug through the polymeric phase of the matrices. On the other hand, the release of hydrophilic drugs from hydrophobic systems in general 6,7 and SR elastomers in particular 8 is the outcome of the osmotic gradient that occurs because of the dissolution of the solute.…”

A drug-laden elastomer for surgical treatment of anal fistula

“…If the cross-linker is not adequate, the cure process can also be inhibited, so the ratio of parts A/B cannot increase indefinitely. Besides, the ratio of parts A/B also has an effect on the network density of the cured silicone elastomer [18]. Less cross-linker may allow a higher density of the cured silicone on the condition that it is enough for the cross-linking process.…”

“…Silicone elastomer has been extensively used for many biomedical applications [18]. It has been reported as carriers for controlled release of watersoluble drugs, hydrophobic drugs, as well as protein drugs [19][20][21][22].…”