Phospholipid Vesicles for Enhanced Drug Delivery in Dermatology

Review Article

J Drug Discov Develop and Deliv. 2014;1(2): 8.

Phospholipid Vesicles for Enhanced Drug Delivery in Dermatology

Željka Vanić*

Department of Pharmaceutical Technology, University of Zagreb, Croatia

*Corresponding author: Željka Vanić, Department of Pharmaceutical Technology, University of Zagreb, A. Kovačića,10000 Zagreb, Croatia

Received: October 10, 2014; Accepted: March 24, 2015; Published: March 25, 2015


Phospholipid vesicles (liposomes) have been widely investigated as carriers for enhancing skin delivery of drugs. The similarity between lipid compositions of liposomes with the skin structures enables liposomes to be used as physiologically acceptable drug delivery nanosystems. By manipulation of their physico-chemical properties the effective skin delivery of the encapsulated/ incorporated drug can be achieved. They can be used as carriers to increase the solubility of the poorly soluble drugs or improve the stability of instable compounds. Phospholipid vesicles enable localized skin delivery of lipophilic drugs, enhance the penetration of hydrophilic drugs and help in reducing the drug irritation. Even without entrapped active compound, they have been shown to improve the skin condition by increasing the hydration level of the skin and integrity of the stratum corneum. The potentials and perspectives of different types of phospholipid vesicles have been summarized in this review, including conventional liposomes, deformable liposomes, ethosomes, invasomes and propylene glycol-containing liposomes, with the emphasis on their potential mechanism of action in enhanced skin delivery.

Keywords: Skin; Topical delivery; Conventional liposomes; Deformable liposomes; Ethosomes; Propylene glycol liposomes


Application of ointments and lotions onto the skin for cosmetic and therapeutic effects has been used for thousands of years. Nowadays, more than one third of drugs under clinical evaluation are related to delivery into or through the skin [1,2]. Regarding easiness of application and patient's accessibility, delivery via the skin represent an ideal route of drug administration for achieving local (dermal) or systemic effects (transdermal delivery) [3].

Skin is the largest human organ which consists of the three anatomically distinct layers; epidermis, dermis and subcutaneous layer (Figure 1). The natural function of the skin is to protect the body from unwanted influences from the environment. The main barrier of the skin is the outermost layer-the stratum corneum. Often described as "brick and mortar"-like structure, stratum corneum is composed of 10-15 thick layers of dead keratinocytes embedded in intercellular lipid matrix, composed of the ceramides, free fatty acids, triglycerides, cholesterol, cholesterol sulphate and sterol/wax esters [6]. This barrier remains slightly open and permeable to the environment to allow evaporation of water from the living cells of the skin. Substances (drugs) which are applied onto the skin have to pass stratum corneum to reach the target cells in the lower layers of epidermis or dermis. Three main pathways are possible: (i) through the hair follicles and associated sebaceous glands, (ii) through the sweat ducts and (iii) across the continuous stratum corneum comprising transcellular and intercellular pathways [6]. Parameters which affect the delivery of topically applied drugs include the size of molecule, the lipophilicity, type of formulation, presence of penetration enhancers and physical state of stratum corneum [7]. It is well known that lipophilic drugs are easily transported through the skin as compared to hydrophilic drugs, especially those of high molecular weight. Therefore, to achieve sufficient penetration of active substances into or through the skin, the barrier properties of the stratum corneum are often reduced by chemical penetration enhancers or physical methods such as iontophoresis, sonophoresis, electroporation and microneedles [8]. Alternative approach is based on the use of drug delivery nanosystems, which are capable to enhance penetration of hydrophilic drugs into the skin and control release and deposition of lipophilic drugs at the site of action [9].