“Development and evaluation of lipid nano-carriers for the treatment of dermatitis”

Abstract

Skin is an important organ that acts as a protective barrier against foreign materials through its multilayered structure. It also prevents the loss of endogenous materials such as water. Drug delivery through the skin either targets the dermal layer or goes deeper to the systemic circulation. Topical delivery is used to treat dermatological conditions such as psoriasis, atopic dermatitis and microbial infections with minimal systemic uptake. This allows for avoidance of first pass metabolism and other gastrointestinal symptoms associated with some medications. In addition, it improves the therapeutic value for active agents and patient drug acceptance. However, low skin penetration is always a limiting factor for the skin delivery of the therapeutic moieties. This is the challenging point that scientists tried to overcome through both physical and chemical methods. Among the successful methods for dermal drug delivery are nanocarriers. Numerous lipid-based delivery systems have been developed starting with liposomes and transferosomes, which are flexible vesicles, containing an edge activator that allows vesicles to squeeze through skin layers. Another type of vesicles are ethosomes, in which ethanol is incorporated in the phospholipid membrane, this allows for both higher penetration power plus superior flexibility than liposomes. Moreover, different successful delivery systems were developed using different classes of penetration enhancers. Those vesicles were able to deliver different hydrophilic and lipophilic drug models deep into skin layers. In addition, other lipid based nanocarriers such as solid lipid nanoparticles were developed. Generally, SLNs increase drug bioavailability, prevent drug degradation and offer controlled drug release. The high contact with the surface of the skin by the nano-range particles increases drug penetration into the skin. Because SLNs are composed of normal and non-toxic lipid content, they are suitable for use on damaged and inflamed skin. BMV is a halogenated corticosteroid with high topical intensity as compared to systemic effect. Moreover, almond oil is a natural remedy that contains vitamin B complex, vitamin E, alpha- tocopherol, and linoleic and oleic acid which are key factors in maintaining a healthy-looking skin. The aim of this work was to maximize the efficiency of topical BMV- almond oil solid lipid nanoparticle systems. Hence, the work in this thesis was divided into two chapters.