A comparison between silicone free and silicone-based emulsions: technological features and in vivo evaluation

Transparent silicone-free shampoo containing proteins with strong hair conditioning properties

OBJECTIVE

With the constant upgrading of healthcare concepts, silicone-free hair products have attracted more attention among consumers. In the present study, transparent silicone-free shampoo containing proteins was successfully fabricated by mixing mild non-sulphate surfactants, compound cationic conditioners, natural silicone oil substitutes, protein conditioners, thickeners, and other auxiliary ingredients. The effects of the type of surfactants, hair conditioners and thickeners, the type and content of proteins, and the mass ratio of compound proteins on the hair foaming performance, hair grooming performance, and penetration performance were investigated.

METHODS

The basic formulation framework for transparent silicone-free shampoo was established at first. Then, various hydrolyzed proteins were further added to the basic formulation in the form of single use or compound use to prepare transparent silicone-free shampoo containing different proteins. The morphology of hair samples and penetration of protein in hair were evaluated with a scanning electron microscope and laser confocal fluorescence microscopy, respectively. And the hair grooming performance was also determined by a dynamic combing tester.

RESULTS

The compound proteins of Croquat WKP PE-LQ-WD and Gluadin® Kera-PLM with mass ratios of 1:9 and 1:1 at 2 wt% total protein content added to the silicone-free shampoo brought a higher contact angle and a lower frictional coefficient than commercial silicone-free shampoo without proteins. In addition, the compound proteins also have the dual effect of adsorbing the hair surface and penetrating deep into the interior of the hair.

CONCLUSION

The combination of cationic modified hydrolyzed protein (e.g., Croquat WKP PE-LQ-WD) and hydrolyzed protein with low molecular weight (e.g., Gluadin® Kera-P LM) at an appropriate mass ratio exhibited a strong synergistic effect on hair conditioning properties. It could provide a significant reference for developing silicone-free hair products with more benefits.

Synthesis of Vinyl-Containing Polydimethylsiloxane in An Active Medium

This research deals with the synthesis of copoly(methylvinyl)(dimethyl)siloxanes by the copolycondensation of dimethyldiethoxy- and methylvinyldimethoxysilane in an active medium, followed by thermal condensation in a vacuum. We achieved a range of copolymers exhibiting finely tuned molecular weights spanning between 1500 and 20,000 with regulated functional methylvinylsiloxane units. Analysis of the microstructure showed that the copolymerization predominantly formed products demonstrating a random distribution of units (R~1). However, an increase in the content of vinyl-containing monomers increases the R parameter, indicating an enhanced tendency towards alternating linkages within the copolymer matrix.

Patient-Centric Design of Topical Dermatological Medicines

Topical treatments are essential approaches to skin diseases but are associated with poor adherence. Topical vehicles have the primary purpose of ensuring drug effectiveness (by modulating drug stability and delivery, as well as skin properties) but have a marked impact on treatment outcomes as they influence patient satisfaction and, consequently, adherence to topical treatments. There is also a wide variety of vehicles available for topical formulations, which can complicate the decisions of clinicians regarding the most appropriate treatments for specific skin disorders. One of the possible strategies to improve topical-treatment adherence is the implementation of patient-centric drug-product design. In this process, the patient's needs (e.g., those related to motor impairment), the needs associated with the disease (according to the skin lesions' characteristics), and the patient's preferences are taken into consideration and translated into a target product profile (TPP). Herein, an overview of topical vehicles and their properties is presented, along with a discussion of the patient-centric design of topical dermatological medicines and the proposal of TPPs for some of the most common skin diseases.

Stability, oxidizability, and topical delivery of resveratrol encapsulated in octenyl succinic anhydride starch/chitosan complex-stabilized high internal phase Pickering emulsions

High internal phase Pickering emulsions (HIPPEs) stabilized with octenyl succinic anhydride starch/chitosan complexes were examined as a topical delivery vehicle for resveratrol. All resveratrol-loaded HIPPEs showed stable gel-like network structures, with the droplet size and microrheological properties largely dependent on the complex concentrations. HIPPEs exhibited strong stability when subjected to light, high temperature, UV radiation and freeze-thaw treatment, and resveratrol retention was greatly improved with the increasing addition of complexes and resveratrol. High amounts of resveratrol facilitated the antioxidant activity of HIPPEs, whereas sustained release of resveratrol was mainly related to the existence of complex interfacial layers. Moreover, HIPPEs overcome the stratum corneum barrier, with an approximately 3-5-fold increase in resveratrol deposition in deep skin compared to bulk oil. In conclusion, the emulsion composition (especially at the particle level) was vital for the effectiveness of HIPPEs as a carrier, which may provide new opportunities to design topical delivery systems.

In Situ Swelling Formulation of Glycerol-Monooleate-Derived Lyotropic Liquid Crystals Proposed for Local Vaginal Application

Hydrogels have been extensively investigated to identify innovative formulations that can fulfill all the necessary purposes to improve local vaginal therapy through the mucosa. Herein, we propose in situ-forming lyotropic liquid crystals (LLCs) derived from a cheap and GRAS (generally recognized as safe) ingredient as an intravaginal delivery system. The system consists of a precursor solution loaded with sertaconazole nitrate as a model drug, which is able to easily swell in a stable three-dimensional structure by absorbing simulated vaginal fluid. Under polarized light microscopy the precursor solution and the formed phase of LLCs showed the typical textures belonging to anisotropic and an isotropic mesophases, respectively. A deep rheological investigation by Kinexus^® Pro proved the stability and strength of the cubic phase, as well as its potential in mucoadhesion. In vitro degradation studies showed a slow matrix erosion, consistent with data obtained from lipophilic drug release studies in simulated vaginal fluid. Therefore, the suggested cubic phase based on lyotropic liquid crystals could represent a valid proposal as a vaginal drug delivery system due to its characteristics of resistance, adhesion and the possibility of providing a slow and controlled release of drugs directly at the administration site.