Required HLB Determination of Some Pharmaceutical Oils in Submicron Emulsions

Catalytic Aquathermolysis of Emulsified Residual Oils with Naphthenates

Catalytic aquathermolysis, a crucial aspect of chemical reutilization, converts the heavy components (such as resins and asphaltenes) of residual oil into lighter components. The use of transition-metal-based catalysts accelerates aquathermolysis reactions. It was observed that iron naphthenate exhibited greater efficiency for residual oils compared to manganese naphthenate and zinc naphthenate. Furthermore, the catalytic aquathermolysis of emulsified residual oil with iron naphthenate demonstrated an outstanding catalytic performance. Under the reaction conditions of 340 °C, 3 MPa, and 2 h, there was a remarkable decrease in viscosity and sulfur content of residual oil by 85.0 and 50.01%, respectively. Additionally, the alterations in the components of residual oils before and after aquathermolysis were examined through a four-component analysis and elemental analysis.

The Fatty Acid Compositions, Irritation Properties, and Potential Applications of Teleogryllus mitratus Oil in Nanoemulsion Development

This study aimed to characterize and investigate the potential of the oils from Gryllus bimaculatus, Teleogryllus mitratus, and Acheta domesticus to be used in nanoemulsions. The oils were extracted by a cold press method and characterized for their fatty acid profiles. Their irritation effects on the chorioallantoic membrane (CAM) were evaluated, along with investigations of solubility and the required hydrophilic-lipophilic balance (RHLB). Various parameters impacting nanoemulsion generation using high-pressure homogenization were investigated. The findings revealed that G. bimaculatus yielded the highest oil content (24.58% w/w), followed by T. mitratus (20.96% w/w) and A. domesticus (15.46% w/w). Their major fatty acids were palmitic, oleic, and linoleic acids. All oils showed no irritation, suggesting safety for topical use. The RHLB values of each oil were around six-seven. However, they could be successfully developed into nanoemulsions using various surfactants. All cricket oils could be used for the nanoemulsion preparation, but T. mitratus yielded the smallest internal droplet size with acceptable PDI and zeta potential. Nanoemulsion was found to significantly enhance the antioxidant and anti-skin wrinkle of the T. mitratus oil. These findings pointed to the possible use of cricket oils in nanoemulsions, which could be used in various applications, including topical and cosmetic formulations.

Enhanced Cosmeceutical Potentials of the Oil from Gryllus bimaculatus de Geer by Nanoemulsions

Purpose

This study aimed to extract the oil from Gryllus bimaculatus de Geer, evaluate its potential for cosmeceutical applications, and develop nanoemulsions to promote the cosmeceutical capabilities of the oil.

Methods

G. bimaculatus oil was produced by the cold pressing method. Its fatty acid compositions were assessed by fatty acid methyl ester/gas chromatographic-mass spectrometry. The antioxidant activities of the oil were investigated in terms of radical scavengers, reducing power, and lipid peroxidation inhibition. The whitening effects were investigated through anti-tyrosinase activities, whilst the anti-aging effects were investigated through inhibition against collagenase, elastase, and hyaluronidase. The irritant effects were investigated by the hen's egg chorio-allantoic membrane test and the cytotoxicity assay in immortalized human epidermal keratinocytes and human foreskin fibroblast cells. The nanoemulsions were developed, characterized, and evaluated for their stability and cosmeceutical properties.

Results

G. bimaculatus oil, rich in linoleic acid (31.08 ± 0.00%), oleic acid (30.44 ± 0.01%), palmitic acid (24.80 ± 0.01%), and stearic acid (7.61 ± 0.00%), demonstrated promising cosmeceutical properties in terms of antioxidant, anti-tyrosinase, and anti-skin ageing activities. Besides, the oil was safe since it induced no irritation or cytotoxicity. G. bimaculatus oil was successfully developed into nanoemulsions, and F1, composed of 1% w/w G. bimaculatus oil, 1.12% w/w polysorbate 80, 0.88% w/w sorbitan oleate, and 97% w/w DI water, had the smallest internal droplet size (53.8 ± 0.6 nm), the narrowest polydispersity index (0.129 ± 0.010), and a pronounced zeta potential (-28.23 ± 2.32 mV). All cosmeceutical activities of the oil were significantly enhanced after incorporation in the nanoemulsions (p < 0.001), particularly the whitening effects.

Conclusion

G. bimaculatus oil nanoemulsion was an attractive cosmeceutical formulation with potent whitening effects, along with antioxidant and anti-aging properties. Therefore, nanoemulsion technology was found to be an effective strategy for improving the cosmeceutical properties of G. bimaculatus oil.

Ultrasound-assisted production and optimization of mini-emulsions in a microfluidic chip in continuous-flow

The use of ultrasound to generate mini-emulsions (50 nm to 1 μm in diameter) and nanoemulsions (mean droplet diameter < 200 nm) is of great relevance in drug delivery, particle synthesis and cosmetic and food industries. Therefore, it is desirable to develop new strategies to obtain new formulations faster and with less reagent consumption. Here, we present a polydimethylsiloxane (PDMS)-based microfluidic device that generates oil-in-water or water-in-oil mini-emulsions in continuous flow employing ultrasound as the driving force. A Langevin piezoelectric attached to the same glass slide as the microdevice provides enough power to create mini-emulsions in a single cycle and without reagents pre-homogenization. By introducing independently four different fluids into the microfluidic platform, it is possible to gradually modify the composition of oil, water and two different surfactants, to determine the most favorable formulation for minimizing droplet diameter and polydispersity, employing less than 500 µL of reagents. It was found that cavitation bubbles are the most important mechanism underlying emulsions formation in the microchannels and that degassing of the aqueous phase before its introduction to the device can be an important factor for reduction of droplet polydispersity. This idea is demonstrated by synthetizing solid polymeric particles with a narrow size distribution starting from a mini-emulsion produced by the device.

Studies on Surfactants, Cosurfactants, and Oils for Prospective Use in Formulation of Ketorolac Tromethamine Ophthalmic Nanoemulsions

Nanoemulsions (NE) are isotropic, dispersions of oil, water, surfactant(s) and cosurfactant(s). A range of components (11 surfactants, nine cosurfactants, and five oils) were investigated as potential excipients for preparation of ketorolac tromethamine (KT) ocular nanoemulsion. Diol cosurfactants were investigated for the effect of their carbon chain length and dielectric constant (DEC), Log P, and HLB on saturation solubility of KT. Hen's Egg Test-ChorioAllantoic Membrane (HET-CAM) assay was used to evaluate conjunctival irritation of selected excipients. Of the investigated surfactants, Tween 60 achieved the highest KT solubility (9.89 ± 0.17 mg/mL), followed by Cremophor RH 40 (9.00 ± 0.21 mg/mL); amongst cosurfactants of interest ethylene glycol yielded the highest KT solubility (36.84 ± 0.40 mg/mL), followed by propylene glycol (26.23 ± 0.82 mg/mL). The solubility of KT in cosurfactants was affected by four molecular descriptors: carbon chain length, DEC, log P and HLB. KT solubility was directly proportional to DEC and the HLB yet, inversely proportional to carbon chain length and log P. All surfactants, except Labrasol ALF, were non-irritant. The majority of cosurfactants were slightly irritant, butylene glycol was a moderate irritant, pentylene and hexylene glycols were strong irritants. These findings will inform experiments aimed at developing NE formulations for ocular administration of KT.

Enhanced Transdermal Delivery of Concentrated Capsaicin from Chili Extract-Loaded Lipid Nanoparticles with Reduced Skin Irritation

The aim of this study was to develop lipid-based nanoparticles that entrapped a high concentration of capsaicin (0.25%) from a capsicum oleoresin extract. The solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) were strategically fabricated to entrap capsaicin without a hazardous solvent. Optimized nanosize lipid particles with high capsaicin entrapment and loading capacity were achieved from pair-wise comparison of the solid lipid mixtures consisting of fatty esters and fatty alcohols, representing small and large crystal-structure molecules combined with a compatible liquid lipid and surfactants (crystallinity index = 3%). This report was focused on selectively captured capsaicin from oleoresin in amorphous chili extract-loaded NLCs with 85.27% ± 0.12% entrapment efficiency (EE) and 8.53% ± 0.01% loading capacity (LC). The particle size, polydispersity index, and zeta potential of chili extract-loaded NLCs were 148.50 ± 2.94 nm, 0.12 ± 0.03, and -29.58 ± 1.37 mV, respectively. The favorable zero-order kinetics that prolonged capsaicin release and the significantly faster transdermal penetration of the NLC attributed to the reduction in skin irritation of the concentrated capsaicin NLCs, as illustrated by the in vitro EpiDerm^TM three-dimensional human skin irritation test and hen's egg test chorioallantoic membrane assay (HET-CAM).

Glycerolipid Composition and Advanced Physicochemical Considerations of Sacha Inchi Oil toward Cosmetic Products Formulation

Sacha inchi oil is a premier raw material with highly nutritional and functional features for the foodstuff, pharmaceutical, beauty, and personal care industries. One of the most important facts about this oil is the huge chemical content of unsaturated and polyunsaturated fatty acids. However, the current available information on the characterization of the triglyceride composition and the advance physicochemical parameters relevant to emulsion development is limited. Therefore, this research focused on providing a detailed description of the lipid composition using high-resolution tandem mass spectrometry and thorough physicochemical characterization to find the value of the required hydrophilic–lipophilic balance (HLB). For this, a study in the interfacial tension was evaluated, followed by the assessment of different parameters such as creaming index, droplet size, viscosity, zeta potential, pH, and electrical conductivity for a series emulsified at thermal stress condition. The results show that fatty acids are arranged into glycerolipids and the required HLB to achieve the maximum physical stability is around 8.

An Evaluation of the Physicochemical Properties of Stabilized Oil-In-Water Emulsions Using Different Cationic Surfactant Blends for Potential Use in the Cosmetic Industry

One of the most complex problems in hair care formulations is the duality of the surfactants used. In this regard, such surfactants must be cationic so as to interact with the negatively charged cuticle surface of hair. However, these interdependencies typically lead to non-ideal values for the required hydrophilic–lipophilic balance (HLB) in the oil phase. This study was designed to evaluate the physicochemical properties of several oil-in-water emulsion prototypes for the potential use in hair conditioners. Here, a base formulation was utilized, incorporating binary mixtures of cationic surfactants in different proportions. The cationic surfactants employed were hydroxyethyl-behenamidopropyl-diammonium chloride, behentrimonium methosulphate, cetrimonium chloride, and (iv) Polyquaterniumpolyquaternium-70. The surfactants were evaluated for their capability to decrease the surface tension in an aqueous solution through contact angle measurements between the oily phase and the aqueous phase. The required HLB of the oil phase was also determined. The emulsification process was developed using standard preparation methods. For three months, the prototypes with high viscosity were packed in containers and stored in a stability chamber at accelerated conditions (40 ± 2 °C and 75 ± 5% RH). During this time, the size, size polydispersity, zeta potential, viscosity, rheological profile, and creaming index were all evaluated monthly. The results showed a slight change in the physical stability of the prototypes, where the droplet size increased moderately, however, did little to destabilize the formulations. This suggests that the mixtures of cationic surfactants used could be useful for technological developments in hair conditioning products.

Determination of composition distributions of multi-particle crystalline samples by sequential dissolution with concomitant particle sizing and solution analysis

Sequential dissolution of multi-particle samples with before-and-after sizing gave composition data that can be assigned to defined sample particle regions.