A novel substrate for testosterone: biodegradable and biocompatible oil gel

The androgen testosterone is less expensive than bone morphogenetic proteins and has been shown to effectively repair bone fractures. However, testosterone is lipophilic and insoluble in water, making it difficult to load into hydrogels, which are common drug carriers. In this study, we prepared a novel oil gel composed of poly(L-lactide) and a poly(trimethylene carbonate) derivative and studied the release of testosterone from the gel. Dimethyl sulfoxide and dimethyl carbonate, which are organic solvents with relatively low toxicities, were used as dispersion media. The oil gel in dimethyl sulfoxide released testosterone faster than that in dimethyl carbonate. In addition, the dimethyl carbonate oil gel was vacuum-dried to reduce the gel porosity and thus slow testosterone release. Therefore, oil gel is a promising substrate for lipophilic drugs, including testosterone. In this study, we prepared a novel oil gel composed of poly(L-lactide) and a poly(trimethylene carbonate) derivative. We investigated the release of testosterone, an inexpensive therapeutic drug for the segmental defect of bones, from the gel. Dimethyl sulfoxide and dimethyl carbonate, which are organic solvents with relatively low toxicities, were used as dispersion media. The oil gel in dimethyl sulfoxide released testosterone faster than that in dimethyl carbonate. In addition, the dimethyl carbonate oil gel was vacuum-dried to reduce the gel porosity and resulted in slow testosterone release.