Development Of New Wet Wipe Formulations Based From Hyaluronic Acid And Tea Tree Hydrosol

Wet wipes has become part of modern life because of their convenience,portability and disposability.Since its conception in the US in 1960 s,wet wipes had diversified into different categories with specific user purposes,and had become billion dollar business and it is still growing.The rise of wet wipes had also spurred the nonwoven industry with the demand for nonwoven fabrics,and the development in new technologies for nonwoven production had helped to create novel wipes for specific applications.Wet wipes on the market include baby wipes,general wet wipes,hand wipes,facial wipes,feminine wipes,disinfectant wipes,moist toilet wipes,household cleaning wipes and industrial cleaning wipes.The use of synthetic fibres as materials for nonwoven fabric of wet wipes has created enormous environmental problems with regard to the lack of biodegradability and clogging up of the public sewage systems when being flushed down to the drainage system.Wet wipes came to China in the 1980 s and was only given a head start when the Severe Acute Respiratory Syndrome(SARS)broke out in 2003,and was later continued by the fears of bird flu in 2004 and swine flu in 2009,the status of wet wipes as essential means of personal hygiene was firmly establish and wet wipes industry flourished.Because of cultural,educational and financial reasons,wet wipes for personal use as a convenient replacement of normal wash and clean procedure is not widely accepted,and although the domestic wet wipes market is approaching 3 billion RMB,the wet wipes market per capita is very low,compared with the US or the EU countries.In connection with our previous work on hyaluronic acid in cosmetics and another work with tea tree hydrosol as an antibacterial agent,we have designed and looked at the liquid formulation using hyaluronic acid as a key ingredient to make products of facial wipe and makeup remover wipes.We had taken the advantages of the antibacterial properties of tea tree hydrosol for it to be used as an ingredient in wet wipe liquid formulation for foot hygiene and hemorrhoid care.For the development of facial wipes and makeup remover wipes,hyaluronic acid as key ingredient for the formulation of wet wipe liquid had been studied with regard to the molecular properties of hyaluronic acid and the selection of surfactants as a variant.The work in particular looked at the use of hyaluronic acid with different molecular weight distribution.Nowadays,the molecular weight distribution of hyaluronic acid is quite wide,ranging from 1 k Da to 3000 k Da on the market.It was revealed that hyaluronic acids possessing different molecular weight have different mechanism of moisturizing skin.Hyaluronic acid with relative large molecular weight keep skin hydrated by forming a transparent hydration film on the surface of the skin,preventing moisture from evaporating from the skin.While hyaluronic acid with relatively smaller molecular weight would potentially be absorbed in a transdermal manner,and lock moisture in a deeper level(or deeply moisturizing skin).Furthermore,the molecular weight of hyaluronic acids is proportional to the viscosity of aqueous solution prepared with the same concentration of hyaluronic acid.Hyaluronic acids with a bigger molecular weight would lead to a larger viscosity of the resultant aqueous solution.Therefore,the molecular weight distribution of hyaluronic acid added to the wet wipes is of great significance to the skin sensation and moisturizing effects.Four hyaluronic acids with molecular weight of 350 k Da,890 k Da,1350 k Da and 1640 k Da were selected in our study to find the optimal combination of hyaluronic acids for facial wet wipes.During this work,we also looked at the hyaluronic acid materials from several manufacturers,hyaluronic acid samples sent by different companies were made into the same concentration of aqueous solutions.These solutions were evaluated through three criteria,including the solution appearance,viscosity and skin sensations.No noticeable differences across the samples were found with the formulations and the user experiences.Considering the company's production capacity and the prices of hyaluronic acids,we chose Dongying First Biochem Industrial Co.,Ltd.as the supplier of hyaluronic acid for our facial wet wipes.The main components of the formulation of wet wipes,apart from hyaluronic acid,include auxiliary humectant,surfactants and preservative systems.For the choice of auxiliary humectant,the often-used glycerin was employed in the formulation as 0.01%.For hyaluronic acid wet wipes,the formulation was further developed to incorporate other surfactants,in particular a mixed system of nonionic glycoside surfactant and amphoteric amino-acid type surfactant.For the choice of surfactants,a surfactant to remove dirt faster and more efficient in a gentle manner is much preferred.Among all the surfactants,alkyl polyglucosides(APGs)is desirable.APGs are a class of non-ionic surfactants widely used in a variety of cosmetic,household and industrial applications.In our case,0.1% of APG0810(C8-10 alkyl glucoside)was used.Preservative system acts as an essential component in wet wipes.In more than half a century for the development of wet wipes,the preservative system has been well developed.Choosing from market's widely used preservative systems,our modified preservative system for hyaluronic acid facial wet wipes include 2-bromo-2-nitropropane-1,3-diol(7.5 ppm).methylisothiazolinone(11.25 ppm),methylchloroisothiazolinone(3.75 ppm)and citric acid 0.06% and phenoxyethanol 0.1%.At the beginning of our work,we applied four hyaluronic acids samples and used 10 different hyaluronic acid combinations.The amount of hyaluronic acids in the liquid component of the wet wipes was set at 0.4%.In order to develop an optimal formulation of hyaluronic acid wet wipes,our preliminary study commenced with sensory tests based with 30 volunteers.The age group of volunteers selected is between 22 to 38(19 female,11 male).The skin sensory evaluation in our study includes five criteria,the moisture sensation,the level of smooth,the absorption time,stickiness and irritation.Three formulations were selected based on the marks for moisturizing sensation,they are formulation 4(HA 890 k Da/ HA 1350 k Da 1:1),formulation 9(HA 890 k Da/ HA 1350 k Da/ HA 1640 k Da 1:1:1)and formulation 10(HA 350 k Da/ HA 890 k Da/HA 1350 k Da/HA 1640 k Da 1:1:1:1).Based on the smoothness evaluation,top three formulations including formulation 5,formulation 6 and formulation 10 were established.The hyaluronic acid distributions of formulations 5 and 6 were 890 k Da/1640 k Da(1:1)and 1350 k Da/1640 k Da(1:1),respectively.We next recorded the absorption time with a stopwatch.The absorption time of these wet wipes ranged from 4.23 s(formulation1,HA 1350 k Da/ HA 890 k Da 1:1)to 5.88 s(formulation 6,HA 1350 k Da/ HA 1640 k Da 1:1).The difference of absorption time for these formulations of wet wipes is quite small,and it is not easy for volunteers to tell which formulation takes the longest time without checking the exact time from stopwatch.Pleasingly,all of these volunteers are satisfied with the absorption time for all the wet wipes.None of 30 volunteers had experienced irritation.According to the preliminary results,four formulations were selected,including formulations 4,6,9 and 10.It was found that the combination use of mixture of hyaluronic acid with different molecular weight range in the liquid formulation,with a preferred mixture of the high and middle molecular weights hyaluronic acid,gave the smooth and luxurious feel.They are next subjected to quantitative analysis of moisturizing efficacy using Moisture Measurement Value(MMV)and Transepidermal Water Loss(TEWL).The TEWL value indicates the loss of water in the stratum corneum and is an important criterion for evaluating the barrier function of the stratum corneum.The lower the TEWL value of the skin,the better the barrier function of the skin,and vice versa.The age of volunteers selected for this study is between 22 to 51(53 people in total,28 female,25 male).According to the usual skin classification criteria,we divided 53 volunteers into 25 normal skins and 28 dry skins.From both MMV and TEWL study results,formulation 9 appeared to be the most practical formulation in general purpose,while huge advantages were shown to be formulation 6 for dry skin.The work on hyaluronic acid formulation for wet wipes has provided basis for further product development into a hybrid product between facial wipe and facial mask.It is possible to have a product for facial care in a form of a wet wipe having hyaluronic acid while possessing a mild cleaning capability as a leave-on product to work as a moisturizer and hydrating agent,which would work well for those who are on the go and want something less complicated but nonetheless similar results like a face mask.We had previously studied the antibacterial activities of tea tree hydrosol as a new material used for disinfection and for cosmetic formulation.The basic formulation of tea tree hydrosol including 0.01% of glycerin,0.1% of benzalkonium chloride,2-bromo-2-nitropropane-1,3-diol(7.5 ppm),methylisothiazolinone(11.25 ppm),methylchloroisothiazolinone(3.75 ppm),0.06% of citric acid and 0.1% of phenoxyethanol.Six different tea tree hydrosol wet wipes were prepared,containing 0%,20%,40%,60%,80% and 100% of tea tree hydrosol,respectively.Paper diffusion method was employed to determine the antibacterial activity of six different wet wipes for Escherichia coli,Staphylococcus aureus and Candida albicans.In general,80% of tea tree hydrosol appeared to be very efficient to reduce all of the bacteria tested in the experiments.The overall antibacterial performance is even better than 100% tea tree hydrosol wet wipes.The use of tea tree hydrosol in wet wipes for general hand cleaning,foot hygiene,or hemorrhoid care has demonstrated the suitability and effectiveness of tea tree hydrosol being used as both a preservative and an antibacterial agent.Formulation containing 40% of tea tree hydrosol in the wet wipe liquid system was applied for general hygiene purpose.Wet wipe formulation with 80% of tea tree hydrosol was prepared and modified for foot hygiene.The typical size of the nonwoven for wet wipes(15 cm×20 cm)might be a bit too small for the average size of feet.Therefore,a larger piece of nonwoven(20 cm×30 cm)is applied for foot use.We also added extra amount of liquid(89% liquid loading,previously 85%)in the wet wipes to give a better moisture sensation.Sensory tests with 30 volunteers(9 female,21 male)were undertaken to evaluate the general performance of tea tree hydrosol wet wipes for foot hygiene.It has revealed that 62% of volunteers have relieved the itchiness of their feet,96% of volunteers experienced significant improvement of smelly feet.Current ingredients used for hemorrhoid care are witch hazel,hamamelis virginiana,and aloe vera.Formulation contains 60% of tea tree hydrosol was modified by adding 0.1% of aloe vera and 0.1% of propylene glycol in the wet wipe liquid and applied for hemorrhoid care.It turns out that 20 volunteers who applied tea tree hydrosol wet wipes revealed a significant reduction of recovering time compared to the control group.It was revealed that 19 of 20 volunteers who applied tea tree hydrosol wet wipes for general hemorrhoid care would like to use this wet wipe again.In this work,the first use of tea tree hydrosol to wet wipe liquid formulation for cleaning and disinfecting purposes has given new addition to products in this wet wipes category for foot hygiene and in particular hemorrhoid care.Two kinds of tea tree hydrosol wet wipe derived from this work are currently in the process of being commercialized with a company that has the manufacturing facilities and the production license.