Equilibrium solubilization of lipophilic therapeutic agents by aqueous solutions of products of catalytic oxyethylation of Croda-type lanolin as model excipients of the class of non-ionic surface active agents.

Research was conducted into the properties and identity of the products of Croda-type hypoallergenic lanolin, which were obtained with the use of a selective catalyst (K-4) and a standard alkaline catalyst (Na/NaOH). The 1HNMR method was employed to assess the content of oxyethylated segments and the analytic level of hydrophilic-lipophilic balance (HLB). Surface activity of products soluble in water with n(TE) > or = 40 was examined and the thermodynamic potential for micelle formation deltaGm(o) was calculated. Basic viscosity and hydrodynamic values were determined for the solubilizers and their micellar adduct with ibuprofen, ketoprofen and naproxen. In addition, the amount of solubilized therapeutic agents c/s/ was examined by means of the spectroscopic method and the micellar partition coefficient--Kw(m) was estimated. The results obtained in the course of research served as a basis for determining the solubilization mechanism and the stability of the micellar adduct for the purpose of application. This enabled the commencement of technological work on the design and manufacture of a model dosage form administered to the skin and containing the products of lanolin oxyethylation.