Topical Diclofenac Reduces Joint Synovitis in Hand Osteoarthritis: A Pilot Investigation Using Fluorescent Optical Imaging.

Purpose: Synovitis, the inflammation of joint synovia, is a prominent feature of osteoarthritis (OA) manifested by enhanced synovial vascularity, endothelial leakage, and perivascular oedema. In this pilot study, we assessed the effect of topical diclofenac in hand OA (HOA) using the established semi-quantitative methods Magnetic Resonance Imaging (MRI) and Ultrasonography (US), and compared them with Fluorescent Optical Imaging (FOI), an emerging imaging modality.

Patients And Methods: Ten patients with symptomatic and diagnosed HOA used topical diclofenac for 14 days, with FOI, MRI, US, and subjective pain assessed at Baseline and after 7 (Day 8), and 14 (Day 15) days of treatment.

Time-Dependent Differences in the Effects of Oleic Acid and Oleyl Alcohol on the Human Skin Barrier.

Oleic acid and oleyl alcohol are commonly used permeation and penetration enhancers to facilitate topical drug delivery. Here, we aimed to better understand the mechanism of their enhancing effects in terms of their interactions with the human skin barrier using diclofenac diethylamine (DIC-DEA), a nonsteroidal anti-inflammatory drug for topical pain management. Oleic acid promoted DIC-DEA permeation through ex vivo human skin more rapidly than oleyl alcohol (both applied at 0.

Visualisation of drug distribution in skin using correlative optical spectroscopy and mass spectrometry imaging.

A correlative methodology for label-free chemical imaging of soft tissue has been developed, combining non-linear optical spectroscopies and mass spectrometry to achieve sub-micron spatial resolution and critically improved drug detection sensitivity. The approach was applied to visualise the kinetics of drug reservoir formation within human skin following in vitro topical treatment with a commercial diclofenac gel. Non-destructive optical spectroscopic techniques, namely stimulated Raman scattering, second harmonic generation and two photon fluorescence microscopies, were used to provide chemical and structural contrast.

Optimization of topical formulations using a combination of in vitro methods to quantify the transdermal passive diffusion of drugs.

This paper describes a new approach to the early-stage optimization of topical products and selection of lead formulation candidates. It demonstrates the application of open flow microperfusion in vitro in conjunction with the Franz diffusion cell to compare time-resolved, 24-hour profiles of diclofenac passive diffusion through all skin layers (including the skin barrier, dermis, and subcutis) resulting from nine topical formulations of different composition. The technique was successfully validated for in vitro sampling of diclofenac in interstitial fluid.

Transdermal Permeation and Skin Retention of Diclofenac and Etofenamate/Flufenamic Acid From Over-the-Counter Pain Relief Products.

Topical pain relief products differ in the type of drug, concentration, and formulation. All these factors influence the drug transit through the skin barrier, and its eventual retention in the skin as a reservoir for subsequent release. In addition, the drug potency can be different, which is important for the product efficacy.

Visualization of Epidermal Reservoir Formation from Topical Diclofenac Gels by Raman Spectroscopy.

Purpose: This work investigated whether topical pain relief diclofenac gels can form a diclofenac reservoir in the epidermal and dermal layers of human skin.

Methods: Excised human skin samples were treated with three topical diclofenac gels ex vivo and examined using Raman microscopy of transversally microtomed sections. The relative diclofenac concentration in the skin layers was calculated as the ratio of the integrated areas of bands characteristic of diclofenac (~445 cm) and skin (Amide I).