Cetero Research in Fargo, North Dakota, conducted this study for PCCA, located in Houston, Texas. The study was designed to characterize the percutaneous absorption of Lorazepam from Lipoderm and Lipoderm Activemax. Absorption was measured in ex vivo human torso skin in vitro, using the finite dose technique and static Franz Diffusion Cells.
Each formulation was evaluated on 3 replicate sections from 3 ex vivo human torso skin donors. The percutaneous absorption of Lorazepam was determined over a 48-hour period with receptor solution samples collection at 0 hour (predose) and 2, 4, 8, 12, 24, 32 and 48 hours. In addition, the glass rod used for dosing, surface wash, stratum corneum, epidermis and dermis were recovered and assessed for drug content. The samples were analyzed for Lorazepam content using a High Performance Liquid Chromatography (HPLC) analytical method developed by Cetero Research Pre-Clinical Dermatology Laboratory.
To characterize the percutaneous absorption of Lorazepam from Lipoderm and Lipoderm Activemax into and through human torso skin using the Franz Finite Dose In Vitro Permeation Test (IVPT) Model.
The in vitro Franz human skin finite dose model has proven to be a valuable tool for the study of percutaneous absorption and the determination of the pharmacokinetics of topically applied drugs. The model uses ex vivo human torso skin mounted in specially designed diffusion chambers allowing the skin to be maintained at a temperature and humidity that match typical in vivo conditions.1 A finite dose (for example, 2 mg/cm2 – 10 mg/cm2) of formulation is applied to the outer surface of the skin and drug absorption is measured by monitoring its rate of appearance in the receptor solution bathing the inner surface of the skin. Data defining total absorption, rate of absorption, as well as skin content can be accurately determined in this model. The method has historic precedent for accurately predicting in vivo percutaneous absorption kinetics.2,3