Preparation and in vitro evaluation of innovative topical formulations containing desloratadine

H1-receptor antagonists are clinically used in the treatment of histamine-mediated allergic conditions such as allergic rhinitis, allergic conjunctivitis, contact dermatitis, rhinorrhea, dermatitis, solar dermatitis. Desloratadine (DL), the active metabolite of loratadine, is a molecule with high affinity for H1 receptors while low affinity for H2 receptors. The most common side effects of oral desloratadine are fatigue, dry mouth and headache. It is in the small molecule class as a molecule, and there are commercially available tablet and syrup formulations. The topical route of drug administration is an area of interest. The main barrier in the topical route is the stratum corneum. There are many factors that affect the permeation and penetration of drugs by the topical route through the skin. These factors can be counted as formulation, active ingredient and physicochemical factors. In topical application, there are various approaches to eliminate the barrier property of the skin and increase the penetration of the active substance through the skin. Microemulsions are transparent, thermodynamically stable, colloidal systems with a droplet size of 10-100 nm, consisting of oil, water and surfactant phases. In recent years, it has been investigated more as skin delivery vehicles for many active substances. These colloidal systems are formed spontaneously, without the need for external energy. Within the scope of this master thesis, microemulsion formulations containing desloratadine were developed. Microemulsion formulations were characterized physicochemically and 6-month stability follow-up was performed. As a result of stability monitoring, an in vitro release study was carried out on the selected formulations. Formulations were compared according to stability and release study data. Based on these data, it is thought that the self-forming desloratadine loaded microemulsion carrier system, which is easy to prepare, can be an alternative formulation to solid and liquid formulations by avoiding systemic side effects.