Modulation of Electroosmotic Flow through Skin: Effect of Poly(Amidoamine) Dendrimers.

The objective of this work is to evaluate the effect of polyamidoamine (PAMAM) dendrimers on electroosmotic flow (EOF) through skin. The effect of size and concentration of dendrimer was studied, using generation 1, 4 and 7 dendrimer (G1, G4 and G7, respectively). As a marker molecule for the direction and magnitude of EOF, a neutral molecule, acetoaminophen (AAP) was used.

Alteration of electroosmotic volume flow through skin by polyethylene glycols.

We have studied the effect of polyethylene glycols (PEGs) on the iontophoretic flux of acetaminophen (AAP) using conventional in vitro iontophoresis methodology. A series of PEGs with average molecular weight (MW) ranging from about 100 to 1,500 was studied. The results were analyzed to explain how PEGs affect the electroosmosis and flux through skin.

Modulation of electroosmosis and flux through skin: effect of propylene glycol.

The effect of propylene glycol (PG) on transdermal flux under current was investigated using conventional in vitro iontophoresis methodology. The results were evaluated to explain how PG affects the electroosmotic volume flow (EVF) and electromigrational flux through skin. As a marker molecule for the direction and magnitude of EVF, a non-charged neutral molecule, acetaminophen (AAP), was used.

Effect of pressure sensitive adhesive and vehicles on permeation of terbinafine across porcine hoof membrane.

The purpose of this study was to investigate characteristics of transungual drug delivery and the feasibility of developing a drug-in-adhesive formulation of terbinafine. The permeation of terbinafine from a PSA matrix across porcine hoof membrane was determined using a plate containing poloxamer gel. The permeation rate of terbinafine across hairless mouse skin was evaluated using a flow-through diffusion cell system.

Recent advances in transdermal drug delivery.

Transdermal delivery of pharmacologically active agents has been extensively studied for the past 40 years. Despite the strong efforts, currently, only about 40 products are in market on about 20 drug molecules, due to the requirements that the patch area should be small enough for the patients to feel comfortable, and to the barrier properties of the stratum corneum. Various approaches to overcome the barrier function of skin through physical and chemical means have been broadly studied.

Pharmacokinetic evaluation and modeling of formulated levodopa intranasal delivery systems.

Levodopa (L-dopa), the metabolic precursor of dopamine, has primarily been used for the treatment of Parkinson's disease (PD) in combination with carbidopa (C-dopa). This study aims to investigate the feasibility of L-dopa nasal delivery systems prepared using maleic acid solution containing 2-hydroxypropyl-beta-cyclodextrin, and to develop pharmacokinetic models. Following oral or intravenous administration of L-dopa plus C-dopa and intranasal dosing of L-dopa in the presence and absence of C-dopa to the rat, the concentrations of L-dopa in plasma and brain were determined using HPLC.

Dissolution kinetics and physical characterization of three-layered tablet with poly(ethylene oxide) core matrix capped by Carbopol.

We have prepared poly(ethylene oxide) (PEO) tablets which have three-layered structure by direct compression. Carbopol (CP) was coated on both sides of the central PEO matrix which contains solid-dispersed nifedipine (NP) in PEG4000. For comparison, physical mixture of PEO with poly(ethylene glycol 4000) (PEG4000) solid dispersion was also prepared.

In vitro and in vivo study of poly(ethylene glycol) conjugated ketoprofen to extend the duration of action.

Ketoprofen-polyethylene glycol (PEG) conjugates (KPEG) were prepared and their potential as a prolonged release system was investigated. Three KPEG conjugates were synthesized from ketoprofen and methoxy PEG with three different molecular weights by esterification in the presence of DCC. The KPEG conjugates were characterized by FT-IR and (1)H NMR spectroscopy.