title: Nortriptyline hydrochloride skin absorption: development of a transdermal patch.
abstract: The influence of propylen glycol (PG), ethanol, and oleic acid (OA) on nortriptyline hydrochloride (NTH) penetration through human epidermis was studied in vitro at two different pH values (5.5 and 7.4). The influence of lactic acid and polysorbate 80 was studied for a pH of 5.5. Permeation studies through Heat Separated Epidermis, as well as the enhancing effect of the different vehicles, showed a pH dependency. A pH value of 5.5 in the donor solution decreases significantly the permeability coefficient (Kp) with respect to a pH value of 7.4 (0.011+/-0.004 x 10(-6) versus 0.36+/-0.04 x 10(-6)cm/s). The vehicles showed an increasing enhancement effect in the order: polysorbate 80>ethanol/PG/OA>PG>ethanol>ethanol/lactic acid>lactic acid at pH 5.5 while they reduced the permeation of NTH at pH 7.4. Considering the results obtained at pH 5.5, the maximum enhancement ratios were found for polysorbate 80 and the combination ethanol/PG/OA (10.72 and 3.90). Both vehicles were selected for designing a NTH transdermal delivery system (NTH-TDS) using (hydroxypropyl)methyl-cellulose as polymer. The NTH-TDS based on the combination of ethanol/PG/OA showed an enhancement ratio with respect to control of 2.09 and the addition of polysorbate 80 to the matrix, of 5.82.
authors.affiliation: Department of Pharmacy and Pharmaceutical Technology, Universitat de València, Valencia, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Melero
authors.forename: T M
authors.initials: TM
authors.lastname: Garrigues
authors.forename: P
authors.initials: P
authors.lastname: Almudever
authors.forename: A Marti N
authors.initials: AM
authors.lastname: Villodre
authors.forename: C M
authors.initials: CM
authors.lastname: Lehr
authors.forename: U
authors.initials: U
authors.lastname: Schäfer
mesh_terms: D000279:Administration, Cutaneous; D000465:Algorithms; D000929:Antidepressive Agents, Tricyclic / Q000008:administration & dosage / Q000493:pharmacokinetics*; D002021:Buffers; D055598:Chemical Phenomena; D002626:Chemistry, Pharmaceutical; D002627:Chemistry, Physical; D002851:Chromatography, High Pressure Liquid; D015194:Diffusion Chambers, Culture; D006801:Humans; D006863:Hydrogen-Ion Concentration; D065347:Hypromellose Derivatives; D066298:In Vitro Techniques; D008055:Lipids / Q000737:chemistry; D008747:Methylcellulose / Q000031:analogs & derivatives; D009661:Nortriptyline / Q000008:administration & dosage / Q000493:pharmacokinetics*; D012869:Skin Absorption / Q000502:physiology*; D012995:Solubility; D012997:Solvents; D013816:Thermodynamics
chemical_list: D000929:Antidepressive Agents, Tricyclic; D002021:Buffers; D008055:Lipids; D012997:Solvents; D065347:Hypromellose Derivatives; D008747:Methylcellulose; D009661:Nortriptyline