Basic Mathematics in Skin Absorption
Symbol Generic units Description A m2 Area of application AUC kg/m3 Area under the curve c kg/m3 Concentration c ss kg/m3 Steady-state concentration C 0 kg/m3 Initial concentration at Cl…
The Effects of Vehicle Mixtures on Transdermal Absorption: Thermodynamics, Mechanisms, Assessment, and Prediction
, where R is the ideal gas constant, T and P are temperature and pressure, x i is the mole fraction of component i, N j are the numbers of…
High Throughput Screening of Transdermal Penetration Enhancers: Opportunities, Methods, and Applications
Fig. 8.1 Schematic of the INSIGHT screening apparatus. The INSIGHT screen is made up of a donor array (top) and a symmetric receiver array (bottom). A single screen can screen…
Non-formulation Parameters That Affect Penetrant-Skin-Vehicle Interactions and Percutaneous Absorption
Fig. 4.1 Schematic illustration of skin (showing epidermis, dermis, hypodermis and skin appendages) and underlying muscles and joints, showing targets of drugs and cosmetics applied to skin for local, systemic…
Mechanistic Studies of Permeation Enhancers
Fig. 7.1 Chemical structures of the enhancers. R, R′ = alkyl chain Corticosterone (CS) was the main model permeant. Estradiol (ES) and hydrocortisone (HC) were the two other steroidal permeants…
Models, Methods, and Measurements in Transdermal Drug Delivery
(9.1) where C 0 is the concentration of the solute in the donor chamber, K is the partition coefficient, or log P of the solute into skin (SC), D is…
Finite and Infinite Dosing
(3.1) where J is the flux of the permeant (mass per cm2), D is the diffusion coefficient and δc/δx is the concentration gradient. To determine how diffusion affects the permeant…
Retardation of Dermal Release by Film Forming Emulsions
Fig. 19.1 Formulations for sustained dermal therapy; left: rapid release of the api from a semisolid formulation and build-up of a reservoir in stratum corneum; right: patch which exhibits a…
Confocal Microscopy for Visualization of Skin Penetration
Fig. 15.1 (a) Pinhole in front of the detector rejects light emerging from out of focus regions. (b) Schematic representation of CLSM optics (Semwogerere and Weeks 2008) Schematic representation of…
Efficacy, Safety and Targets in Topical and Transdermal Active and Excipient Delivery
Fig. 23.1 Keratinocyte culture IC50 and estimated unbound epidermal concentrations after human epidermal membrane penetration of sunscreens from a 1 % mineral oil solution (Adapted from Hayden et al. (2005))…
