Biodegradable Amphoteric Surfactants in Titration-Ultrasound Formulation of Oil-in-Water Nanoemulsions: Rational Design, Development, and Kinetic Stability

Amphoteric amphiphilic compounds, due to their unique properties, may represent a group of safe and biocompatible surface-active agents for effective colloidal stabilization of nanoformulations. For this reason, the aim of this work was to develop and characterize the oil-in-water nanoemulsions based on two betaine-derived surfactants with high biodegradability, i.e., cocamidopropyl betaine and coco-betaine. In the first step, we investigated ternary phase diagrams of surfactant-oil-water systems containing different weight ratios of surfactant and oil, as the betaine-type surfactant entity (S), linoleic acid, or oleic acid as the oil phase (O), and the aqueous phase (W) using the titration-ultrasound approach. All the received nanoemulsion systems were then characterized upon droplets size (dynamic light scattering), surface charge (electrophoretic light scattering), and morphology (transmission electron as well as atomic force microscopy). Thermal and spinning tests revealed the most stable compositions, which were subjected to further kinetic stability analysis, including turbidimetric evaluation. Finally, the backscattering profiles revealed the most promising candidate with a size <200 nm for potential delivery of active agents in the future cosmetic, pharmaceutical, and biomedical applications.

Formulation of Chewable Toothtablets Containing Mangosteen Rind Extract and Market Feasibility Study in Capital District of Nakhon Pathom Province

The objective of this research aimed to 1. formulate chewable toothpaste tablets containing mangosteen rind extract, 2. compare the suitable filler between lactose anhydrous and mannitol that adsorbs mangosteen rind extract by flowability and appearance indicators, 3. study the effect of type and amounts of foaming agents on stability of foam that leads to appropriate formulation, and 4. study market feasibility of chewable toothpaste tablets containing mangosteen rind extract. Survey method and self-administered questionnaire was used for data collection both before and after formulation in capital district of Nakhon Pathom. Thirty participants were selected and categorized into five groups which are tourists, dental patients, pharmacy students at Silpakorn University, office workers and dentists. After data collection is done, it was analyzed by using descriptive statistics. Results showed that mannitol is an appropriate adsorbent. It showed proper color and appearance as well as good flowability of extract. Cocamidopropyl betaine was selected as foaming agent. According to the survey, participants are interested in product. In addition, some dental specialists suggested to add fluoride. Overall, this product is interested and accepted among participants. Therefore, consumers are likely to buy chewable toothpaste tablet containing mangosteen rind extract.

Study into biodegradation of cocamidopropyl betaine, an amphoteric surfactant, by Pseudomonas bacteria and activated sludge

The paper examines the biodegradation rate of cocamidopropyl betaine by bacteria of the genus Pseudomonas and activated sludge. The following microorganisms were taken as destructor strains: Pseudomonas fluorescens TR (VKPM B-4881), Pseudomonas putida TP-19 (B-6582), Pseudomonas stutzeri T (B-4904), Pseudomonas putida TSh-18 (B-2950), Pseudomonas putida TO (B-3959), Pseudomonas mendocina 2S (B-4710), Pseudomonas oleovorans TF4-1L (B-8621) and activated sludge obtained at activated sludge reactors of a Kuzbass plant. Biooxidation of surfactant samples was carried out in 250 cm3 glass flasks, placed into an incubator shaker, at a constant temperature of 30ºС for pure cultures and 18ºС for activated sludge. The destructor strain should reduce the surfactant concentration to safe values within a minimum time interval. Pseudomonas stutzeri T (B-4904) and Pseudomonas fluorescens TR (B-4881) strains provided the shortest half-life of the surfactant under study – 2.5 and 2.6 days, respectively. For Pseudomonas putida TO (B-3959), Pseudomonas putida TSh-18 (B-2950) and Pseudomonas oleovorans TF4-1L (B-8621) strains, these values amounted to 3.0, 4.5 and 4.9 days, respectively. The maximum half-life of the surfactant under study was demonstrated by Pseudomonas mendocina 2S (B-4710) and Pseudomonas putida TP-19 (B-6582) microorganisms – 5.5 and 6.0 days, respectively. The maximum biodegradation of the surfactant was observed under its exposure to the biocenosis of microorganisms. Over 14 days, the concentration of cocamidopropyl betaine decreased to 0.27% of its initial concentration. The efficiency of Pseudomonas bacteria as destructors of surfactants was demonstrated. Bacteria of this genus exhibit a shorter generation time and a higher rate of biomass growth when compared to other strains and a shorter period of adaptation to surfactants when compared to activated sludge. Capable of reducing surfactant concentrations to safe values in a minimum time interval, Pseudomonas strains can be used as an effective agent in the development of technologies for wastewater purification from amphoteric surfactants.

Soapwort (Saponaria officinalis L.) Extract vs. Synthetic Surfactants—Effect on Skin-Mimetic Models

Our skin is continuously exposed to different amphiphilic substances capable of interaction with its lipids and proteins. We describe the effect of a saponin-rich soapwort extract and of four commonly employed synthetic surfactants: sodium lauryl sulfate (SLS), sodium laureth sulfate (SLES), ammonium lauryl sulfate (ALS), cocamidopropyl betaine (CAPB) on different human skin models. Two human skin cell lines were employed: normal keratinocytes (HaCaT) and human melanoma cells (A375). The liposomes consisting of a dipalmitoylphosphatidylcholine/cholesterol mixture in a molar ratio of 7:3, mimicking the cell membrane of keratinocytes and melanoma cells were employed as the second model. Using dynamic light scattering (DLS), the particle size distribution of liposomes was analyzed before and after contact with the tested (bio)surfactants. The results, supplemented by the protein solubilization tests (albumin denaturation test, zein test) and oil emulsification capacity (using olive oil and engine oil), showed that the soapwort extract affects the skin models to a clearly different extent than any of the tested synthetic surfactants. Its protein and lipid solubilizing potential are much smaller than for the three anionic surfactants (SLS, ALS, SLES). In terms of protein solubilization potential, the soapwort extract is comparable to CAPB, which, however, is much harsher to lipids.

Effect of nonionic and amphoteric surfactants on salivary pellicles reconstituted in vitro

Surfactants are important components of oral care products. Sodium dodecyl sulfate (SDS) is the most common because of its foaming properties, taste and low cost. However, the use of ionic surfactants, especially SDS, is related to several oral mucosa conditions. Thus, there is a high interest in using non-ionic and amphoteric surfactants as they are less irritant. To better understand the performance of these surfactants in oral care products, we investigated their interaction with salivary pellicles i.e., the proteinaceous films that cover surfaces exposed to saliva. Specifically, we focused on pentaethylene glycol monododecyl ether (C12E5) and cocamidopropyl betaine (CAPB) as model nonionic and amphoteric surfactants respectively, and investigated their interaction with reconstituted salivary pellicles with various surface techniques: Quartz Crystal Microbalance with Dissipation, Ellipsometry, Force Spectroscopy and Neutron Reflectometry. Both C12E5 and CAPB were gentler on pellicles than SDS, removing a lower amount. However, their interaction with pellicles differed. Our work indicates that CAPB would mainly interact with the mucin components of pellicles, leading to collapse and dehydration. In contrast, exposure to C12E5 had a minimal effect on the pellicles, mainly resulting in the replacement/solubilisation of some of the components anchoring pellicles to their substrate.

Drag Reduction in the Flow of Aqueous Solutions of a Mixture of Cocamidopropyl Betaine and Cocamide DEA

The study presents results of rheological tests and measurements of pressure drops occurring during the flow of aqueous solutions of a mixture of drag reducing surfactants: cocamidopropyl betaine (CAPB, zwitterionic surfactant) and cocamide DEA (nonionic surfactant) through straight pipes. Tests were carried out at different CAPB/DEA weight ratios and different total concentrations of surfactants in the solution. Rheological measurements demonstrate the formation of a shear-induced structure (SIS) in the temperature range below 10 °C, which provides evidence for the presence of wormlike micelles in CAPB/DEA solutions. Drag reduction was observed during the flow of CAPB/DEA solutions in the temperature range from 3 to 45 °C, however, above 25 °C the degree of drag reduction was markedly decreased. The lower temperature limit at which drag reduction occurs depends on the CAPB and DEA weight ratio in the solution. In the range of higher temperatures, during the flow of CAPB/DEA solutions (similarly to flexible-chain polymer solutions) the onset of drag reduction is noted above a certain critical value of the Rec,0 number, whose value depends on the temperature of the solution, diameter of the pipe and the weight ratio of surfactants. At the same time, the critical value of wall shear stress τw,c0 corresponding to the critical value of Rec,0 is approximately independent of pipe diameter. The critical value of the Rec,0 number has been linked to the clouding of CAPB/DEA solutions.

Study on Interaction of Carboxylic Acid Gemini Surfactant with Cocamidopropyl Betaine in Aqueous Solution

The interaction of carboxylic acid gemini surfactant 4,8-didodecyl-3,9-dioxo-6-hydroxy-4,8-diaza-1,11-undecanedicarboxylic acid (CGS12) with amphoteric surfactant cocamidopropyl betaine (CAPB) at 258C and pH 7.0 has been investigated using pH titration, surface tension, dynamic light scattering (DLS) and cryogenic transmission electron microscopy (Cryo-TEM) measurements. The pH titration results show that CGS12 exhibits anionic surfactant properties and CAPB exists as a zwitterionic form at pH 7.0. The surface tension results show that the critical micelle concentration (CMC) values of the CAPB/CGS12 mixture are low, and basically exhibit a decreasing trend with decreasing molar ratio of CAPB (XCAPB). The variation of the CMC of the mixture reveals that the mixing is close to ideal. The DLS results indicate that the CAPB/ CGS12 mixture mainly forms the larger aggregates with the hydrate radii approximately 70-145 nm at various XCAPB. The Cryo-TEM images further demonstrate the CAPB/CGS12 mixtures mainly form vesicles. The results indicate that the aggregate size and microstructure of the mixture change little with the variation of XCAPB.

Enzymatic biofilm destabilisation to support mechanical cleansing of inserted dental implant surfaces: an in-vitro pilot study

Peri-implantitis is caused by microbial contamination and biofilm formation on the implant surface. To achieve re-osseointegration, the microbes must be completely removed from the surface. Adjunctive to mechanical cleaning, chemical treatment with enzymes or other substances could optimise the treatment outcome. Therefore, we investigated the efficacy of different enzymes, a surfactant, and a chelator in destabilising dental polymicrobial biofilm. The biofilm destabilising effect of the glycosidases α-amylase, dextranase, DispersinB®, and lysozyme, as well as the proteinase subtilisin A, and the nuclease Benzonase®, the chelator EDTA, and the surfactant cocamidopropyl betaine were investigated on biofilms, inoculated with plaque on rough titanium discs. The test and the control solutions were incubated for 15 min at 36 °C on biofilms, and loosened biofilm mass was removed by shear stress with a shaker. Fluorescence-stained biofilms were microscopically analysed. Acceptable cell tolerability concentrations of test substances were determined by the MTT (tetrazolium dye) assay on the MG-63 cell line. A statistically significant biofilm destabilising effect of 10% was shown with lysozyme (2500 µg/ml).