Thematic area of your work "Nanocomposites and nanomaterials")

Poly-lactic acid/silica composites for controlled release of active substances
Kozakevych R.B., Polyshchuk L.M., Tertykh V.A.
Chuiko Institute of Surface Chemistry of National Academy of Sciences of Ukraine, 17 General Naumov Str., 0316, Kyiv, Ukraine
E-mail: kozakevych@gmail.com

Many controlled-release drug-delivery systems are based upon the principle of active compound dissolution at a precisely necessary rate. Biodegradable natural polymers have many medical applications in controlled delivery systems active substances. Among the biopolymers used in medical and pharmaceuticals industries these days, polylactide (PLA) is considered as one of the best materials due to its biocompatibility, complete biodegradability and non-toxic nature of degradation products.
The formation of nanocomposites based on hybrids of an organic matrix and inorganic materials can show improved characteristic. This work is devoted to the development of synthesis methods and the study of properties of composites in which the base is silica and aminosilica, and the main function of the polymer matrix is performed by polylactide (PLA). The production of composite materials was carried out by polymerization of L-lactide with the opening of its ring in the surface layer of a silica. Obtained materials were characterized FTIR, TG and tested in vitro release active components. Active ingredient of diclofenac sodium (99.5%wt, Vaishali Pharmaceuticals, India) and ibuprofen (98.5%wt, Sigma-Aldrich) was used as received. In vitro release studies of the prepared biocomposites were executed according to the requirements of the State Pharmacopoeia of Ukraine using the rotating basket method. The active agent concentrations in the release liquids were registered spectrophotometrically by measuring the increase in absorbance at 230 nm for ibuprofen and diclofenac at 276 nm.
It has been demonstrated that composite based on poly-lactic acid and silica are able prolong the release of active substances for a long period of time. Thus, controlled release effect could improve the therapeutic effect, prolong the biological activity, and decrease the administration frequency.