Using Nuclear Magnetic Resonance to Troubleshoot a Stability Issue in a Real-World Formulation Chassis-Application to Consumer Oral Healthcare.

With direct application to current and future consumer healthcare products, this research sheds light on the importance of packaging and its potential effects on both Active Pharmaceutical Ingredient (API) delivery and stability. Industrially sourced, proprietary experimental formulations (PEFs), specifically oral cleansers, based on salicylic acid and hydrogen peroxide, discolored over time at different rates, depending on packaging type used. This discoloration stemmed from an interplay of two factors, involving both spontaneous formulation degradation and the interaction of both degradants and salicylic acid with the internal surface of the packaging.

A 3D Printed Device for Generation of Stratified Epithelia at the Air-Liquid Interface.

Air-liquid interface (ALI) cultures are used to produce stratified epithelial tissues , notably for the production of oral mucosal equivalents. Currently, there are few purpose-built devices, which aim to enhance the ease and reproducibility of generating such tissue. Most ALI cultures utilize stainless steel grids or cell culture inserts to elevate the matrix or scaffold to the surface of the culture media.

Investigation of the Formation of Squalene Oligomers Exposed to Ultraviolet Light and Changes in the Exposed Squalene as a Potential Skin Model.

UV-induced oligomerisation of squalene was undertaken to indicate the potential for squalene-containing biological systems to exhibit rheology changes. DOSY NMR enabled the determination of the molecular weight (MW) range using Stokes-Einstein Gierer-Wirtz Estimation (SEGWE Calculator, University of Manchester). This approach was validated by Atmospheric Solids Analysis Probe Time of Flight Mass Spectrometry (ASAP TOF MS).

Characterizing the nanomechanical properties of microcomedones after treatment with sodium salicylate ex vivo using atomic force microscopy.

Objective: The treatment of acne presents a major clinical and dermatological challenge. Investigating the nanomechanical properties of the microcomedone precursor lesions using atomic force microscopy (AFM) may prove beneficial in understanding their softening, dissolution and prevention. Although the exact biochemical mechanism of NaSal on microcomedones is not fully understood at present, it appears to exhibit a significant exfoliation effect on the skin via corneodesmosome dissolution.

Topical delivery of niacinamide: Influence of neat solvents.

Niacinamide (NIA) has been widely used in cosmetic and personal care formulations for several skin conditions. Permeation of topical NIA has been confirmed in a number of studies under infinite dose conditions. However, there is limited information in the literature regarding permeation of NIA following application of topical formulations in amounts that reflect the real-life use of such products by consumers.

Scope and limitations of nuclear magnetic resonance techniques for characterisation and quantitation of vitamin D in complex mixtures.

Background: The accurate determination of vitamin D in skin is of considerable importance in evaluating penetration of skin health products through the different layers of the skin.

Objective: We report on the characterisation and quantitation of vitamin D in an idealised sample and in complex mixtures which mimic that of a typical skin cream, using qNMR, 2D NMR and DOSY techniques.

Methods: The characterisation and quantitation conditions were acquired over several heterogeneous samples, allowing for analysis of how the dynamic range and complexity of the different sample mixtures affect the limits of detection (LOD) and limits of quantitation (LOQ) of vitamin D.

3-O-ethyl-l-ascorbic acid: Characterisation and investigation of single solvent systems for delivery to the skin.

l-ascorbic acid (AA), commonly known as vitamin C, has been widely used in topical formulations for many years as an antioxidant and anti-aging ingredient. However, the physicochemical properties of AA are not optimal for skin uptake and the molecule is also unstable, readily undergoing oxidation on exposure to air. The compound 3-o-ethyl-l-ascorbic acid (EA) has been developed as a stable vitamin C derivative and has been used in topical products.

In vitro studies investigating the dentin tubule-occlusion properties of an experimental anhydrous stannous fluoride dentifrice.

Purpose: To evaluate in vitro the ability for an experimental anhydrous 0.454% w/w stannous fluoride dentifrice to occlude dentin tubules.

Methods: Scanning electron microscopy (SEM) was used to assess tubule occlusion and the resistance of the occlusion to dietary acid in a 4-day model, where bovine dentin was treated with product twice daily with acid challenges administered on Days 3 and 4.

Rhabdomyolysis associated with cerivastatin: six cases within 3 months at one hospital.

Rhabdomyolysis is an uncommon complication associated with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors. We observed six cases of cerivastatin-associated rhabdomyolysis: two patients developed acute renal failure requiring hemodialysis, and one patient died. Four of the patients had impaired renal function, and five were prescribed drugs with the potential to interact with cerivastatin.