Polymer-coated liposomes for hydration of oral mucosa. Investigation of water adsorption, retention, and release properties.

Abstract

Ailments from a dehydrated mouth may result in problems with food intake, such as chewing and swallowing, with smiling and appearance, and some of them may cause pain. A system to increase hydration of oral mucosa will reduce patient ailments, or the frequency of them, and increase quality of life.

The focus of this thesis is to study the potential of polymer coated liposomal systems for hydration of the oral mucosa. To establish an in vitro method for determination of the water adsorption/retention capacity of liposomes and polymers by using the DVS method and to examine the release of a marker to determine different leakage profiles. Finally, to see if there is a possible correlation between the water adsorption/retention abilities and the release profiles.

The water adsorption/retention abilities of liposomes and polymers have been investigated with a DVS-Intrinsic apparatus. This was executed at 35 C with a % RH ranging from 0-95 %. The release profiles of CF from EggPC/DOTAP coated with negative polymers and EggPC/EggPG and DPPC/DPPG coated with a positive polymer have been studied at 35 C. Release from uncoated liposomes were determined as well.

The DVS Intrinsic studies showed that the uncoated liposomes display the same water adsorption/retention abilities. Of the different polymers LM Pectin had the highest adsorption and retention ability of water, although it was not significantly different. Alginate and Chitosan shared adsorption/retention properties of water. PNIPAAM had the lowest adsorption/retention ability, and was significantly different. The release studies showed that EggPC/DOTAP coated with LM Pectin had a higher release than uncoated or coated EggPC/DOTAP. EggPC/DOTAP coated with PNIPAAM had the lowest release profile, although never significantly different.

The liposome formulation that would be a good candidate for future xerostomia treatments is dependent on the release profile that is optimal for the purpose of hydrating a mouth. If a high release profile is desirable, EggPC/DOTAP coated with LM Pectin would be a good choice.