Stability and Rheological Properties of the Novel Silica-Based Organogel-A Drug Carrier with High Solubilization Potential.

Dissolution of a poorly soluble active pharmacological substance in a drug carrier usually requires advanced techniques and production equipment. The use of novel carriers such as microemulsions, vesicles, or nanocarriers might entail various limitations concerning production cost, formulation stability, or active substance capacity. In this paper, we present a novel fumed silica-based organogel as a low-cost, simple preparation drug or cosmetic carrier with interesting rheological properties and high solubilization capacity. The objective of the study was to characterize the utility aspects of the new dermatological base with special emphasis on stability, rheology, and release studies. Various formulations of a silica organogel base with poorly soluble active pharmacological substances such as propolis or ibuprofen were prepared and tested. The studies of thermal stress, enforced syneresis, and long-term stability were performed along with analyses of rheological profiles of alkali-dependent sol-gel transformation and organogel release. The new drug vehicle shows high thermodynamic stability, thixotropic rheology and first-order release profile. Such properties are promising for commercial utility as a dermatologically applied base for poorly soluble substances.