HEXYLENE GLYCOL

The utilization of polyols as green solvents for extracting bioactive compounds from plant materials has gained attention due to their safety and inert behavior with plant bioactive chemicals. This study explores the sustainable extraction of phenolic compounds and natural antioxidants from coffee silverskin using the microwave-assisted extraction (MAE) method with polyol-based solvents: glycerin, propylene glycol (PG), butylene glycol (BG), methylpropanediol (MPD), isopentyldiol (IPD), pentylene glycol, 1,2-hexanediol, and hexylene glycol (HG). A comparative analysis was conducted on conventional and non-conventional solvent extractions, focusing on their impact on the bioactive compounds of MAE, encompassing parameters such as total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activities like the 1,1-diphenyl-2-picrylhydrazyl radical scavenging assay (DPPH), the 2,2'-azino-bis(-3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging assay (ABTS), and the ferric reducing antioxidant power assay (FRAP). The highest values were observed for TPC with aqueous-1,2-hexanediol extraction (52.0 ± 3.0 mg GAE/g sample), TFC with aqueous-1,2-hexanediol extraction (20.0 ± 1.7 mg QE/g sample), DPPH with aqueous-HG extraction (13.6 ± 0.3 mg TE/g sample), ABTS with aqueous-pentylene glycol extraction (8.2 ± 0.1 mg TE/g sample), and FRAP with aqueous-HG extraction (21.1 ± 1.3 mg Fe (II) E/g sample). This research aims to advance eco-friendly extraction technology through natural plant components, promoting sustainability by minimizing hazardous chemical use while reducing time and energy consumption, with potential applications in cosmetics.

Glucocorticoids rarely cause anaphylaxis. Common methods for the determination of allergens include in vivo skin prick test (SPT) and intradermal skin test (IDST) and the in vitro basophil activation test (BAT). However, to our knowledge, the best strategy for diagnosing glucocorticoid-induced anaphylaxis has not been elucidated. A 10-year-old boy was admitted to our hospital because of 2 weeks of fever and arthralgia. He had not been treated with glucocorticoids before, including methylprednisolone (mPSL). He was suspected to have bacterial myositis and was treated with ceftriaxone. However, his symptoms persisted for > 2 weeks. Autoinflammatory arthritis was suspected, and he was treated with mPSL sodium succinate (MPS) pulse therapy (30 mg/kg). After 15 min of mPSL injection, he had wheezing and generalized wheal formation with decreased oxygen saturation. As anaphylaxis was suspected, mPSL was discontinued, and olopatadine and oxygen were administered. The symptoms improved considerably without the use of epinephrine and disappeared in 30 min. One month after discharge, SPT, IDST, and BAT were performed without discontinuing his prescribed oral prednisolone. SPTs for MPS, hydrocortisone sodium succinate (HCS), prednisolone sodium succinate (PSS), dexamethasone sodium phosphate (DSP), and betamethasone sodium phosphate (BSP) were negative. IDSTs for MPS, HCS, and PSS were positive, whereas those for DSP and BSP were negative. By contrast, BATs for MPS, HCS, and PSS were negative. Although glucocorticoid-induced hypersensitivity caused by nonmedicinal ingredients such as lactose, carboxymethylcellulose, polyethylene glycol, and hexylene glycol has been reported; the glucocorticoids tested in this patient did not contain any of these nonmedicinal ingredients. As the glucocorticoids that were positive on IDST share a succinate ester, this might have caused MPS-induced anaphylaxis. We report the case of MPS-induced anaphylaxis diagnosed by IDST but not BAT. In case reports of glucocorticoid-induced anaphylaxis in the literature, most patients were diagnosed with SPT or IDST. These results suggest that BAT should be considered when IDST and SPT are negative. Further studies are necessary to clarify the best strategy for diagnosing glucocorticoid-induced anaphylaxis.

Patients receiving radiation therapy due to oral cancer develop complications such as hyposalivation, mucositis, oral infections, dental hypersensitivity and caries. Mouthrinses can alleviate some of these problems. To investigate the in vitro antimicrobial properties and cytotoxicity of an experimental mouthrinse. The mouthrinse contained 30% hexylene glycol (glycerine), 7% potassium nitrate and 0.025% sodium fluoride. The minimal inhibitory concentration (MIC) of these ingredients and the mixture was determined for C. albicans, S. aureus and S. mutans over 24 hours at different concentrations. The MICs of two commercial mouthrinses, Corsodyl and Plax, were also determined using the same organisms. All mouthrinses were then tested to determine the percentage kill over 1, 2, and 3 minutes. The MICs for hexylene glycol were 10%, 30% and 10% for C. albicans, S. aureus and S. mutons respectively. Potassium nitrate and sodium fluoride had no antimicrobial effects. The MIC of Corsodyl was 0.016 mg/ml for all the test organisms. The MIC for Plax varied from 0.0002 mg/ml to 0.001 mg/ml. The kill rates for all mouthrinses were acceptable, with no statistical differences between them. The experimental mouthrinse was not toxic to human oesophageal SCC cells after 1 minute exposure. At the time of the experiment, the costs of a similar quantity of the experimental mouthrinse, Corsodyl and Plax were R5.24, R30.00 and R10.00 respectively. The experimental mouthrinse was cost-effective and proved to have an antimicrobial effect and could be used safely to alleviate oral infections, desensitize teeth, improve oral hygiene and control dental caries in cancer patients after radiation therapy.

We report a case of severe contact urticaria with systemic involvement resembling an anaphylactic reaction, following the application of a topical corticosteroid. This was caused by hexylene glycol, an excipient in the formulation. Glycols are widely used in cosmetics, foods and topical and systemic drugs. In particular, glycols are present in many topical drugs used by dermatologists. To our knowledge, this is the first case in the literature of a potentially life-threatening immediate-type reaction in the context of a contact urticaria syndrome due to hexylene glycol. The classification of contact urticaria syndrome and the allergenic potential of glycols are reviewed. Dermatologists should be aware of the contact urticaria syndrome and of the increasing use of glycols in topical drug formulation in order to identify possible adverse reactions.

Propylene glycol (propane-1,2-diol) is the only diol widely used in dermatology. Pentane-1,5-diol is mainly used as a plasticizer in cellulose products and adhesives, in dental composites and in brake fluid compositions and as a preservative for grain. However, pentane-1,5-diol is also an effective solvent, water-binding substance, antimicrobial agent and preservative and may therefore replace several ingredients in a skin composition. The release of tri-iodothyroacetic acid (TRIAC) and percutaneous absorption of hydrocortisone and mometasone furoate with either pentane-1,5-diol or propane-1,2-diol and 2-methyl-pentane-2,4-diol (hexylene glycol), respectively, as enhancers was compared. The release of TRIAC was 21% higher when pentane-1,5-diol was used as an enhancer instead of propane-1,2-diol. The percutaneous absorption of hydrocortisone through the skin was increased 12 times with propane-1,2-diol compared to 4.4 times with pentane-1,5-diol. However, the percutaneous absorption of hydrocortisone into the skin was 50% higher with pentane-1,5-diol compared to propane-1,2-diol. There was no significant difference, between the original mometasone furoate cream, with 2-methyl-pentane-2,4-diol, and the new cream with pentane-1,5-diol in the amount of mometasone furoate that was absorbed into the skin and through the skin. However, the cosmetic properties of the new mometasone furoate cream was superior to the original mometasone furoate cream, for examples, no bad odour, more even texture, goes better into the skin and has less greasiness. Pentane-1,5-diol can be used as a technology platform, which adds a series of desirable properties to dermatological preparations and enhances product usability. This will result in improved formulations for a series of major and commonly used dermatological drugs. When used in pharmaceutical topical preparations, pentane-1,5-diol will increase the percutaneous absorption of the active substance and it is an efficient antimicrobial agent that will act as an effective preservative in topical formulations. Pentane-1,5-diol is cosmetically attractive, has low risk for skin and eye irritation compared to other diols, low toxicity risk and no bad odour.

We investigated the development of a topical indomethacin gel formulation of suitable consistency using Carbopol ETD 2001 as the gelling agent. Topical gel formulations containing 1% w/w indomethacin (IND), 1% w/w Carbopol ETD 2001 (C2001), 1% of trethanolamine (TEA), 30% hexylene glycol (HG) and 10% polyethylene glycol (PEG 300) were prepared with excipients Tween 80, PVP 25, both Tween 80 and PVP 25 or neither agent. These four gel formulations were tested after a period of 1 and 4 weeks at storage temperature of 6 degrees C, 20 +/- 2 degrees C and 45 degrees C. Physical evaluation of the stability of these gels was carried out by microscopic and rheological tests, measurement of pH and by visual inspection. Rheological properties were studied using the cone and plate method at shear rates of 600 to 6000 1/s. Viscosities corresponding to shear rates were also calculated. Our results indicated that C2001 could be used as a gelling agent for IND in topical preparations. IND-C2001 gels were clear and exhibited an acceptable appearance; gel behaviour was non-Newtonian and pseudoplastic. The addition of either Tween 80 or PVP 25 to the base gel formulation significantly increased the shear stresses and viscosity of the gels. These novel formulations exhibited good physical stability throughout the 4-week examination periods as inferred from pH measurements and microscopic examination. Additionally, the non-Newtonian pseudoplastic behaviour of the gels was maintained throughout storage, with only a minimal decrease in gel viscosity after 4 weeks. Differences in consistencies of the four formulations, although initially apparent, were no longer evident after 4 weeks of storage for all temperature conditions examined. Gels stored at high temperature (45 degrees C) developed a dark yellow color and decreased in viscosity compared to other storage temperature.

Topical gel formulations containing a non-steroidal anti-inflammatory drug, indomethacin (IND), were prepared using 20% w/w Lutrol PF-127 as a gel-forming agent, and 16, 20 and 24% w/w Hexylene glycol (HG) or polyethylene glycol 300 (PEG) as solvents. 1% w/w Tween 80 and 1% w/w PVP 25 were added as excipients. The effects of the amounts of solvent and excipients on the physical characteristics of IND gel such as consistency, appearance, crystallization, pH and viscosity were studied. The results indicated that 1% w/w IND is able to form a structural gel. The viscosity values were calculated from the rheograms which were determined by a Haake Rotovisco sensor at a shear rate of 10,000 l/s. Viscosities corresponding to shear rates of 1000, 3000, 6000 and 9000 l/s were also calculated. Yield points were approximated from the rheograms. Although all IND gels maintained their pseudoplastic flow behaviour, their viscosities decreased markedly with increasing shear rates. Furthermore, increasing the amount of HG or PEG gave a more viscous gel except for the 24 w/w% HG gels which turned a jelly with or without either Tween or PVP. The difference in viscosities was explained by the changes in the gel compositions. 20% of PEG-1% PVP ranked first in viscosity followed by 16% PEG-1% PVP, 16% PEG-1% Tween, 24% PEG, 20% PEG-1% Tween and 16% HG-1% PVP. The results indicate that the excipients influence the physical characteristics of the gels. The optimum concentration for gels manifesting as strength of gel was 20% PEG in combination with 1% PVP which had the highest viscosity and yield value at a low shear rate.

Atopic dermatitis is a severe chronic skin disease often deteriorated by the presence of microorganisms and often responds well to treatment with potent corticosteroids. However, the long-term use of potent topical corticosteroids are accompanied by side-effects such as skin atrophy. To study the effect and safety of prophylactic treatment with mometasone furoate fatty cream (contains hexylene glycol) for 6 months in patients with atopic dermatitis. Sixty-one of 68 (90%) patients were still free of their disease after 6 months of twice weekly treatment and only one showed possible treatment related signs of skin atrophy. The number of Staphylococcus aureus and Pityrosporum ovale were significantly reduced in cleared patients. Mometasone furoate fatty cream is effective and safe both for treatment and as a prophylaxis in patients with atopic dermatitis.

The penetration enhancer, 1-[2-(decylthio)ethyl]azacyclopentan-2-one (HPE-101), significantly enhanced the excretion of topically applied [14C]indomethacin when dissolved in dipropylene glycol, triethylene glycol, diethylene glycol, 1,3-butylene glycol, trimethylene glycol, glycerin, water, silicone or triethanolamine, but not when dissolved in ethanol, isopropyl alcohol, oleyl alcohol, olive oil, peppermint oil, isopropyl myristate or hexylene glycol. HPE-101 significantly enhanced the excrection of [14C]indomethacin, [14C]nicotinic acid, [14C]5-fluorouracil, [3H]oestradiol and [3H]triamcinolone acetonide, but not that of [3H]testosterone. HPE-101 also significantly enhanced the excretion of [14C]indomethacin applied to intact skin of rabbit, guinea-pig and rat, and to tape-stripped skin of guinea-pig, but did not enhance the excretion of [14C]indomethacin applied to tape-stripped skin of rat or rabbit.

We developed a facile preparation method of oil-in-water (O/W) Pickering emulsion in an emollient formulation using basil extract ( Ocimum americanum L.) as a solid particle stabilizer by fine-tuning the concentration and mixing steps of common cosmetic formulas, such as humectants (hexylene glycol and glycerol), surfactant (Tween 20), and moisturizer (urea). The hydrophobicity of the main phenolic compounds of basil extract (BE), namely, salvigenin, eupatorin, rosmarinic acid, and lariciresinol, supported high interfacial coverage to prevent coalescence of globules. Meanwhile, the presence of carboxyl and hydroxyl groups of these compounds provides active sites for stabilizing the emulsion using urea through the formation of hydrogen bonds. Addition of humectants directed the in situ synthesis of colloidal particles during emulsification. In addition, the presence of Tween 20 can simultaneously reduce the surface tension of the oil but tends to inhibit the adsorption of solid particles at high concentrations, which otherwise formed colloidal particles in water. The level of urea and Tween 20 determined the stabilization system of the O/W emulsion, whether interfacial solid adsorption (Pickering emulsion, PE) or colloidal network (CN). Variation of the partition coefficient of the phenolic compounds present in basil extract facilitated the formation of a mixed PE and CN system with better stability. The addition of excess urea induced interfacial solid particle detachment, which caused the oil droplet enlargement. The choice of stabilization system determined the control of antioxidant activity, diffusion through lipid membranes, and cellular antiaging effects in UV-B-irradiated fibroblasts. Particle sizes of less than 200 nm were found in both stabilization systems, which is beneficial for maximizing their effects. In conclusion, this study provides a technological platform to realize the demand for natural dermal cosmetic and pharmaceutical products with strong antiaging effects.

Alkanediols are often used as alternative antimicrobial preservatives for dermal formulations, e.g., hydrophilic creams. These substances show an antimicrobial effect due to their amphiphilic structure. At the same time, their amphiphilic behavior enables various interactions with the cream base itself. Therefore, the effect of four different alkanediols, namely 1,2-pentanediol, 2-methyl-2,4-pentanediol (hexylene glycol), 1,2-hexanediol, and 1,2-octanediol on the physical stability of a nonionic hydrophilic cream was investigated. Further, the incorporation of the alkanediols into lamellar structures of the cream was evaluated using differential scanning calorimetry (DSC) and small-angle X-ray scattering (SAXS) measurements. The interaction with the mixed crystals of the cream was found to increase with raising alkyl chain length of the added alkanediol. As a result, consistency and stability of the cream are slightly impaired. A test for efficacy of antimicrobial preservation according to the European Pharmacopoeia (Ph.Eur.) revealed that the antimicrobial activity is directly linked to the length of the alkyl chain of the alkanediols. 2-Methyl-2,4-pentanediol differs from both findings. This compound has non-vicinal hydroxy groups which result in a reduced amphiphilicity compared to the others. Consequently, it has a smaller impact on the colloidal structure of the cream and shows a comparatively low antimicrobial activity.

The stability of 20 topical gel formulations containing drug, 1% w/w indomethacin (IND), and 20% w/w Pluronic (PF-127) as a gel-forming agent, hexylene glycol (HG) and polyethylene glycol 300 (PEG) in different amounts (16, 20 and 24% w/w) as solvents and 1% w/w polyvinyl pyrrolidone (PVP, K-25) and Tween as excipients was determined by appearance and consistency of the gels, microscopy, pH and rheological measurements after 1 and 4 weeks storage, at 6 degrees C, 20 +/- 2 degrees C and 45 degrees C. Viscosity values were determined from rheograms by a Haake Rotovisco sensor at shear rates of 1000 to 10,000 l/s. The relationship between effectors (temperature and storage time) and response (viscosity) was determined using multiple regression analysis. All formulations were stable at room temperature (20 +/- 2 degrees C). The consistency of the gels containing HG and PEG decreased during storage at 6 degrees C. Storing the gels at 6 degrees C resulted in the precipitation of IND, but when PVP was incorporated into the IND-PF-127 gels, the stability of the gels was improved. All IND gels sustained their pseudoplastic flow behaviour. The viscosity decreased as storage time increased. A statistically significant model was obtained, showing that the effect of storage temperatures on the viscosity was much less than the effect of storage time.