Special Issue “Current and Evolving Practices in the Quality Control of Cosmetics” [Editorial]

Quality Control (QC) testing of Cosmetic personal care and fragrance products is a key part of the products’ launch to the market [...

Effect of Drug Loading Method and Drug Physicochemical Properties on the Material and Drug Release Properties of Poly (Ethylene Oxide) Hydrogels for Transdermal Delivery

Novel poly (ethylene oxide) (PEO) hydrogel films were synthesized via UV cross-linking with pentaerythritol tetra-acrylate (PETRA) as cross-linking agent. The purpose of this work was to develop a novel hydrogel film suitable for passive transdermal drug delivery via skin application. Hydrogels were loaded with model drugs (lidocaine hydrochloride (LID), diclofenac sodium (DIC) and ibuprofen (IBU)) via post-loading and in situ loading methods. The effect of loading method and drug physicochemical properties on the material and drug release properties of medicated film samples were characterized using scanning electron microscopy (SEM), swelling studies, differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FT-IR), tensile testing, rheometry, and drug release studies. In situ loaded films showed better drug entrapment within the hydrogel network and also better polymer crystallinity. High drug release was observed from all studied formulations. In situ loaded LID had a plasticizing effect on PEO hydrogel, and films showed excellent mechanical properties and prolonged drug release. The drug release mechanism for the majority of medicated PEO hydrogel formulations was determined as both drug diffusion and polymer chain relaxation, which is highly desirable for controlled release formulation

PREDICTIVE MODELING OF LONG-TERM STABILITY OF DRUG-IN-ADHESIVE TRANSDERMAL DRUG DELIVERY SYSTEMS

PREDICTIVE MODELING OF LONG-TERM STABILITY OF DRUG-IN-ADHESIVE TRANSDERMAL DRUG DELIVERY SYSTEMS K DODOU University of Sunderland, Sunderland SR1 3SD, UK Transdermal patches are medicated dosage forms that are applied on the skin for the delivery of the active ingredient to the systemic circulation. The attachment of the patch on the skin is due to the adhesive ability of the pressure-sensitive adhesive (PSA) polymer1. With my research group we focused on the drug-in-adhesive patch design, where the active ingredient is incorporated in the PSA, and we have explored the following challenges: • Effect of drug incorporation on the adhesive performance of the PSA. My research findings increased knowledge and understanding on how rheological parameters translate to adhesive performance criteria for different types of pressure sensitive adhesives, and provided new insights and practices on the incorporation of drugs in the adhesive films. Via this work, we established how the rheological properties of adhesives can be used as a quality control indicator for the adhesive performance of transdermal patches2,3. • Long-term stabilisation of drug against crystallisation in the PSA via polymeric amorphous solid dispersions. Drug crystallisation in dosage forms is a formulation defect because it hinders drug release. My research identified formulation and manufacturing approaches to prevent drug crystallisation in transdermal films via amorphous solid dispersions4. Drug stabilisation in lipophilic PSAs (such as silicones and polyisobutylenes) requires the addition of a stabiliser polymer that would form H-bonding interactions with the drug. Whereas drug stabilisation in polar PSAs (ie acrylic) could be feasible via H-bonding interaction with the PSA. We therefore developed predictive models for the estimation of the required polymer amount to stabilise a given drug concentration in lipophilic PSAs5 and for the long-term stability assessment of the drug in polar PSAs6. I would like to acknowledge the financial support from IChemE, Schwarz Pharma and UCB Pharma. 1. K Dodou (2011) The use of adhesive films in transdermal and mucoadhesive dosage forms. In: Adhesive Properties in Nanomaterials, Composites and Films. Nova Science Publishers, New York, pp. 83-93. 2. KY Ho, K Dodou, Rheological studies on pressure sensitive silicone adhesives and drug-in-adhesive layers as a means to characterise adhesive performance, Int.J.Pharm. 333(1-2), 24-33 (2007) 3. HM Wolff, Irsan, K Dodou, Investigations on the viscoelastic performance of pressure sensitive adhesives in drug-in-adhesive type transdermal films, Pharm.Res. 31(8), 2186-2202 (2014) 4. K Dodou, W Saddique, Effect of manufacturing method on the in-vitro drug release and adhesive performance of drug-in-adhesive films containing binary mixtures of ibuprofen with poloxamer 188. Pharm.Dev.Tech. 17(5), 552-561 (2012) 5. C Chenevas-Paule, HM Wolff, M Ashton, M Schubert, K Dodou, Development of a predictive model for the stabilizer concentration estimation in microreservoir transdermal drug delivery systems (MTDDS) using lipophilic pressure sensitive adhesives as matrix/carrier. J.Pharm.Sci. 106(5), 1371-1383 (2017) 6. C Chenevas-Paule, HM Wolff, M Ashton, M Schubert, K Dodou, Development of a predictive model for the long term stability assessment of drug-in-adhesive transdermal films using polar pressure sensitive adhesives as carrier/matrix. J.Pharm.Sci. 106(5), 1293-1301 (2017

Novel Crosslinked HA Hydrogel Films for the Immediate Release of Active Ingredients

Novel crosslinked hyaluronic acid (HA) hydrogel films were previously invented by reacting the HA polymer with the PT (Pentaerythritol Tetra-acrylate) crosslinker over basic pH conditions in the oven. HA is considered a natural polymer present in cosmetic as well as pharmaceutical formulations. This current study aimed to highlight the effect of loading method (post-loading and in situ) of selected actives (salicylic acid and niacinamide B3) in the hydrogel films and then study their release kinetics. Differential scanning colometry (DSC) and Fourier transform infrared spectroscopy (FTIR) analysis evidenced the loading of the actives and full release from the HA hydrogel films, while the scanning electron microscopy (SEM) demonstrated the morphological changes to the films during the study by comparing the average molecular weight between crosslinks (M????c), gel fraction, crosslinking density (Ve) and mesh size (xi) of the films. The loading percentage of the SA and B3 showed high percentage loading of actives via both loading methods. In conclusion, the (95?100 release of the actives achieved from the HA hydrogel films within 10 min revealed that the films are an efficient immediate release system of actives

Novel Crosslinked HA Hydrogel Films for the Immediate Release of Active Ingredients

Novel crosslinked hyaluronic acid (HA) hydrogel films were previously invented by reacting the HA polymer with the PT (Pentaerythritol Tetra-acrylate) crosslinker over basic pH conditions in the oven. HA is considered a natural polymer present in cosmetic as well as pharmaceutical formulations. This current study aimed to highlight the effect of loading method (post-loading and in situ) of selected actives (salicylic acid and niacinamide B3) in the hydrogel films and then study their release kinetics. Differential scanning colometry (DSC) and Fourier transform infrared spectroscopy (FTIR) analysis evidenced the loading of the actives and full release from the HA hydrogel films, while the scanning electron microscopy (SEM) demonstrated the morphological changes to the films during the study by comparing the average molecular weight between crosslinks (M¯¯¯¯c), gel fraction, crosslinking density (Ve) and mesh size (ξ) of the films. The loading percentage of the SA and B3 showed high percentage loading of actives via both loading methods. In conclusion, the (95–100%) release of the actives achieved from the HA hydrogel films within 10 min revealed that the films are an efficient immediate release system of actives

A Novel Quality Control Method for the Determination of the Refractive Index of Oil-in-Water Creams and Its Correlation with Skin Hydration

The sensory properties of cosmetic products can influence consumers’ choice. The accurate correlation of sensory properties, such as skin hydration, with the material properties of the formulation could be desirable. In this study, we aimed to demonstrate a new method for the in vitro measurement of the refractive indices (RIs) of turbid creams. The critical wavelength of each cream was obtained through direct measurement using a sun protection factor (SPF) meter; the wavelength value was then applied in the Sellmeier equation to determine the RI. The results obtained from the in vitro skin hydration measurement for each cream correlated with their RI values. This suggests that RI measurements could be a useful predictive tool for the ranking of creams in terms of their skin hydration effects