Creator:
Walicka, Anna ; Iwanowska-Chomiak, Beata
Contributor:
Title:
Fractal model of transdermal drug delivery
Group publication title:
Subject and Keywords:
drug delivery ; human skin ; epidermis ; fractal models
Abstract:
Skin, separating the vital organs of a human body, is a desirable route for drug delivery. However, the intact skin is normally permeable only for drug molecules with a low molecular weight. The stratum corneum (SC), being the outermost layer of the skin and the epidermis being the second - more permeable - layer of the skin, play an essential function in transdermal drug delivery. Physical and chemical methods of skin poration are used to enhance transdermal drug delivery. ; Each poration leads to an irregular system of pores which are connected with a system of micro-capillaries passing through the epidermis. Both the systems by their irregularity form a fractal porous matrix. Drugs administrated by this matrix can be either suspensions and solutions or creams and gels, therefore they have to be modelled as non-Newtonian fluids. To analyse the fluid flow through the porous matrix the model of the epidermis is assumed as gobbet-and-mortar with the tortuous mortar of variable thickness and after transition from the mortar to the tube one considered classical and fractal capillary flows of selected non-Newtonian fluids. ; Fractal expressions for the flow rate, velocity and permeability of fluids flow in a porous matrix are derived based on the fractal properties of the epidermis and capillary model. Each parameter in the proposed expressions does not contain any empirical constant and has a clear physical meaning and the proposed fractal models relate the flow properties of considered fluids with the structural parameters of the epidermis as a porous medium. The presented analytical expressions will help understand some of the physical principles of transdermal drug delivery.
Publisher:
Zielona Góra: Uniwersytet Zielonogórski
Date:
Resource Type:
Format:
DOI:
Pages:
Source:
IJAME, volume 23, number 4 (2018)