Studies on liposome, gel and lipogelosome formulations containing sodium hyaluronate

Sodium hyaluronate (Na-HA) is a natural polymer with mucopolysaccharide structure which provides viscoelasticity to the skin. Na-HA is produced by recombinant deoxyribonucleic acid technology (DNA) from Streptococcus zooepidemicus. In this thesis study, the moisturizing effectiveness of Na-HA on skin was investigated in liposome, gel and lipogelosome formulations. For this purpose, 16 different liposome formulations were prepared by thin film technique with using Na-HA (45 kDa) and without Na-HA in various type of phospholipids; dimyristoylphosphatidylcholine (DMPC), 1,2-dimyristoyl-sn-glycero-3-phosphoracglycerol (DMPG), dipalmitoylphosphatidylcholine (DPPC) and phospholipon 100H (PL 100H). The liposomes prepared by film technique were characterized by mean particle size and size distribution, entrapment capacity, zeta potential, phospholipid efficiency, liposome type determinations. Polarized light microscopy (PLM), scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques were employed for obtaining size distribution and surface appearance and lamellarity. Poloxamer (PXM 188 and PXM 407) and Carbopol derivatives (C 940 and U 21) were used as gelling agents to prepare liposome loaded gel formulations. In vitro release of Na-HA from liposome, Na-HA lipogelosome and marketed formulation of Na-HA was studied by flow through cell method. The optimum formulation was Phospholipon 100H: SA: CHOL (7:1:2) containing Na-HA (L 37). The mean particle size, zeta potential and entrapment capacity were found as 1899 nm ± 13.01, -20.9 mV ± 0,46 and 14.95 %, respectively for the formulation L 37 . Then L 37 formulation was incorporated into the U 21 gel with 1:1 (w/w) ratio (LG 8). The preliminary in vivo studies were performed on 15 female volunteers. With or without Na-HA liposome, lipogelosome and marketed formulation were applied to volunteers for two weeks twice a day. All parameters as changes in humidity levels, sebum content and the pH-level on the skin surface were determined and evaluated by using the Multiprobe Adapter Systems (Corneometer, sebumeter, pH- meter, respectively). The changes of deepness of wrinkles on the skin surface were measured by Skin-visiometer. The increment of moisture level was found 30.36 ± 0.12 % for LG 8 formulation. As a result, LG 8 formulation has improved skin hydration and better compliance than the conventional formulations.