The present invention relates to the field of antimicrobial formulations that are suitable for sanitizing skin. More specifically, the present invention relates to an antimicrobial sanitizing formulation that provides effective skin sanitization and exhibits low flammability, while containing sufficient humectant for moisturization of the skin.
BACKGROUND ART

[0002] Nosocomial infections, also known as hospital-acquired infections, offer a significant challenge to healthcare providers, while community-based infections are a major public health concern around the world. COVID 19 has been proven to be more likely to spread through close, unprotected contact with infected patients and asymptomatic individuals.
[0003] This may give us knowledge regarding prevention and control of nosocomial infections in the future. The World Health Organization (WHO) encourages that hand hygiene be achieved by basic handwashing with soap and water or by utilizing hand rub products to help in minimizing the spread of germs.
[0004] As a result, regulatory authorities, particularly the World Health Organization (WHO), put significance on hand sanitization as a main criterion of infection management. Hand hygiene is a basic approach to limit the transmission of dangerous microbes such as multidrug-resistant diseases and nosocomial infections.
[0005] This is the reason for emphasis on hand hygiene and surface cleaning in limiting the spread of germs, where substances such as sanitizers play an important role. Hand sanitizers can be either alcohol-based or alcohol-free formulations (liquid, gel, or foam) that are designed for rapid administration to the hands. After rubbing such formulations into the hands, they dry quickly, eliminating the need for soap, water, and drying aids.
[0006] Because of the decreased efficacy and smaller spectrum of the alcohol-free preparations, alcohol-based hand sanitizers are recommended to alcohol-free preparations in controlling the spread of disease. Also, the World Health Organization (WHO) advises alcohol-based hand sanitizer (ABHS) because of its ability to denature germ proteins and inactivate viruses, thereby defending against bacteria and viruses.863882A
[0007] US5863882A discloses formulations of the invention comprise a suspension of a sanitizing formulation, bacterial spores, surfactants, a thickening agent, and abrasive particles all contained in aqueous solution. These formulations can be used for cleaning and sanitizing bathroom fixtures, sinks, toilet bowls, and other dirty and contaminated surfaces, and have the advantages of being a good surface cleaning agent and a good sanitizer along with providing the long-term effect of beneficial bacteria that control pathogens and degrade wastes both on the surface and in the sewage, system associated with the surface being treated
[0008] AU2007295050B2 discloses an aqueous disinfectant formulation can comprise an aqueous vehicle, including water, from 0.001 wt.% to 10.0 wt.% of a per oxygen, and an alcohol. Additionally, from 0.001 ppm to 50,000 ppm by weight of a transition metal based on the aqueous vehicle content can also be present. The formulation can be substantially free of aldehydes. Alternatively, or additionally, the transition metal can be in the form of a colloidal transition metal, such as colloidal silver or alloy thereof
[0009] Conventionally, many sanitizing formulations have been developed and commercialized in the market. However, if sanitizing solution having high content of the alcohol is overused, it can cause skin dryness.
[0010] In order to overcome the aforementioned drawbacks, there is a need in the art to develop an alcohol-based sanitizing formulation that can moisturize and protect the skin from the dryness caused by the regular use of alcohol-based hand sanitizer.
OBJECTS OF THE INVENTION

[0011] The principal object of the present invention is to overcome the disadvantages of the prior art by providing the synergy caused due to consumption of the multiple herbal ingredients together which resulted in production of a combined total effect which being much greater then sum of individual agents.
[0012] An object of the present invention is to develop an antimicrobial sanitizing formulation that denatures the microbes present on the skin upon application.
[0013] Another object of the present invention is to synthesize an antimicrobial sanitizing formulation that exhibits low flammability, and contains a moisturizing amount of a humectant.
[0014] Yet another object of the present invention is to provide a sanitizing formulation that is effective for repeated use for the general public and various medical professional environments.
[0015] Another object of the present invention is to prepare a sanitizing formulation that is non-irritating and skin-friendly.
[0016] The foregoing and other objects of the present invention will become readily apparent upon further review of the following detailed description of the embodiments as illustrated in the accompanying drawings.
SUMMARY OF THE INVENTION

[0017] The present invention relates to an antimicrobial formulation having a moisturizing agent for lubricating the skin in order to combat the dryness induced by alcohol.
[0018] According to an embodiment of the present invention, an antimicrobial sanitizing formulation, comprising, i) isopropyl alcohol in the range of 0.1%- 80% w/w, ii) an emollient in the range of 0.1%-15% w/w, hydrogen peroxide in the range of 0.1 0.13% w/w, iii) citric acid in the range of 0.1% to 2.0% w/w, iv) silver nitrate in the range of 0.1% to 0.5% w/w, and v) a fragrance imparting agent in the range of 0.1% to 2.0% w/w.
[0019] According to another embodiment of the present invention, the emollient is preferably an aloe vera extract. The fragrance imparting agent is selected from a group which may include but not limited to lavender, tea tree and lemongrass. The formulation may comprise of elements which may include but not limited to distilled water, essential oils and color imparting agent.
[0020] According to another embodiment of the present invention, the method for preparing the sanitizing formulation, comprises of mixing all the elements in appropriate proportion to obtain a uniform sanitizing formulation. The uniform sanitizing formulation may be used in the form of foam, cream, or liquid gel.
[0021] While the invention has been described and shown with reference to the preferred embodiment, it will be apparent that variations might be possible that would fall within the scope of the present invention.
BRIEF DESCRIPTION OF DRAWINGS

[0022] So that the manner in which the above-recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may have been referred by embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
[0023] These and other features, benefits, and advantages of the present invention will become apparent by reference to the following text figure, with like reference numbers referring to like structures across the views, wherein:
[0024] Figure 1 illustrates a flow chart demonstrating the efficacy test methodology.
DETAILED DESCRIPTION OF THE INVENTION

[0025] While the present invention is described herein by way of example using embodiments and illustrative drawings, those skilled in the art will recognize that the invention is not limited to the embodiments of drawing or drawings described and are not intended to represent the scale of the various components. Further, some components that may form a part of the invention may not be illustrated in certain figures, for ease of illustration, and such omissions do not limit the embodiments outlined in any way. It should be understood that the drawings and the detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the scope of the present invention as defined by the appended claim.
[0026] As used throughout this description, the word "may" be used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense, (i.e., meaning must). Further, the words "a" or "an" mean "at least one” and the word “plurality” means “one or more” unless otherwise mentioned. Furthermore, the terminology and phraseology used herein are solely used for descriptive purposes and should not be construed as limiting in scope. Language such as "including," "comprising," "having," "containing," or "involving," and variations thereof, is intended to be broad and encompass the subject matter listed thereafter, equivalents, and additional subject matter not recited, and is not intended to exclude other additives, components, integers, or steps. Likewise, the term "comprising" is considered synonymous with the terms "including" or "containing" for applicable legal purposes. Any discussion of documents, acts, materials, devices, articles, and the like are included in the specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention.
[0027] In this disclosure, whenever a formulation or an element or a group of elements is preceded with the transitional phrase “comprising”, it is understood that we also contemplate the same formulation, element, or group of elements with transitional phrases “consisting of”, “consisting”, “selected from the group of consisting of, “including”, or “is” preceding the recitation of the formulation, element or group of elements and vice versa.
[0028] The present invention is described hereinafter by various embodiments with reference to the accompanying drawing, wherein reference numerals used in the accompanying drawing correspond to the like elements throughout the description. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiment set forth herein. Rather, the embodiment is provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art. In the following detailed description, numeric values and ranges are provided for various aspects of the implementations described. These values and ranges are to be treated as examples only and are not intended to limit the scope of the claims. In addition, several materials are identified as suitable for various facets of the implementations. These materials are to be treated as exemplary and are not intended to limit the scope of the invention.
[0029] The present invention pertains to an antimicrobial sanitizing formulation that maintains personal hygiene without causing dryness to the skin. The formulation developed herein has a pleasant smell.
[0030] According to an embodiment of the present invention, the antimicrobial sanitizing formulation, comprising, i) isopropyl alcohol in the range of 0.1%- 80% w/w, ii) an emollient in the range of 0.1%-15% w/w, hydrogen peroxide in the range of 0.1 0.13% w/w, iii) citric acid in the range of 0.1% to 2.0% w/w, iv) silver nitrate in the range of 0.1% to 0.5% w/w, and v) a fragrance imparting agent in the range of 0.1% to 2.0% w/w.
[0031] Isopropyl alcohol (IPA) is an amphiphile chemical compound. This property allows it to bond with and break down water-based membranes and disrupt protein structures suspended in water, thereby preventing the growth of organisms by denaturing their proteins and dissolving their lipids.
[0032] The emollient used in the formulation is preferably an aloe vera extract. Here, aloe vera is safe, skin friendly and helps to moisten the skin and prevent skin dryness caused by using alcohol. Furthermore, aloe vera contains antibacterial, antifungal, and antiviral properties which aids in preventing growth of microorganisms.
[0033] Hydrogen peroxide used in the formulation, inactivates the spores present in the bulk solutions or additives. It also shows suboptimal virucidal activity against SARS-CoV-2. Moreover, hydrogen peroxide increases the germicidal potency and cleaning performance of the sanitizing formulation
[0034] Further, citric acid used for preparing the formulation has been used as surface sanitizers for inactivating viruses. Silver nitrate has been used as antiseptics in the formulation for long-lasting antibacterial properties to improve the performance of sanitizing formulation against pathogens.
[0035] Here, the fragrance imparting agent is selected from a group which may include but not limited to lavender, tea tree and lemongrass. The fragrance imparting agent provides a pleasant smell and enhances aesthetic value of the formulation by reducing the smell of alcohol.
[0036] According to another embodiment of the present invention, the above formulation may also include fragrances consisting of essential oils and synthetic fragrances to provide the desired odor. The final volume of the formulation is complete by adding distilled water to make up volume up to 100ml as per WHO protocol.
[0037] Also, the sanitizing formulation may also be applied on absorbent paper or cloth for its applications as a swab or wiping purposes. The formulation may comprise of elements which may include but not limited to distilled water and color imparting agent. The method for preparing the sanitizing formulation, comprises of mixing all the elements in appropriate proportion to obtain a uniform sanitizing formulation.
[0038] The uniform sanitizing formulation may be used in the form of foam, cream, or liquid gel. In all the embodiments, formulations are checked after using the WHO-based handwash protocol. Here, WHO hand sanitizer is used as a control to check the efficacy of the various formulations tested.
Efficiency test
[0039] Different formulations are prepared by varying the concentration of the components. The efficacy test of the formulations is conducted to test the ability of the formulation for being used as hand sanitizers. The experiments were performed in triplicates.
[0040] Preparation and efficacy testing of tested hand rub was in accordance with EN 1500 method as described by WHO (WHO Guidelines on Hand Hygiene in Health Care). The methodology as discussed in figure 1 is used to test the antimicrobial activity of other formulations in the examples described below
EXAMPLE 1
[0041] The sanitizing formulation comprises of isopropyl alcohol (70%), aloe vera (15%), hydrogen peroxide (0.125%), silver nitrate (0.001%), and fragrance imparting agent and varying concentration of citric acid, and is adjusted to 100% (w/v) using distilled water. Table 1 shows the effect of altering the concentration of citric acid while the concentrations of the other ingredients remain constant.
Table 1: Different sanitizing formulations wherein HR1: hand rub 1; HR: hand rub 2; HR3: hand rub 3
Ingredient HR 1 (%) HR 2 (%) HR 3 (%)
Isopropyl alcohol 70 70 70
Aloe vera 15 15 15
Hydrogen peroxide 0.125 0.125 0.125
Citric acid 0.5 1 2
Silver nitrate 0.001 0.001 0.001
Fragrance imparting agent 0.5 0.5 0.5
Distilled water To make up the total volume to 100 ml
[0042] Amongst the three different formulations evaluated in terms of varying concentration of citric acid, all the three solutions showed no growth of bacteria indicating effectiveness but had a sticky texture due to high concentration of aloe vera.
EXAMPLE 2
[0043] Table 2 shows the different formulation obtained by varying concentrations of isopropyl alcohol and citric acid, while other ingredients remain fixed.
Table 2: Different sanitizing formulations wherein HR1: hand rub 1; HR: hand rub 2; HR3: hand rub 3; HR3: hand rub 4
Ingredient HR 1(%) HR 2(%) HR 3(%) HR 4(%)
Isopropyl alcohol 60 60 60 60
Aloe vera 7.5 7.5 7.5 7.5
Hydrogen peroxide 0.125 0.125 0.125 0.125
Citric acid 0.1 0.5 1 2
Silver nitrate 0.001 0.001 0.001 0.001
Fragrance imparting agent 0.5 0.5 0.5 0.5
Distilled water To make up the total volume to 100 ml
[0044] Bacterial growth can be seen in neat or pre-treatment finger impressions. When the efficacy was tested, HR 3 and HR 4 exhibited no growth, however HR 1 and HR 2 showed a few colonies with all three bacteria. As a result, IPA (60%) and citric acid (0.15% and 0.5%) are removed (Table 2). The remaining formulations are chosen for further examination.
EXAMPLE 3
[0045] Table 3 shows the effect of varying concentrations of isopropyl alcohol while other ingredients remain fixed.
Table 3: Different sanitizing formulations wherein HR1: hand rub 1; HR: hand rub 2; HR3: hand rub 3
Ingredient HR 1(%) HR 2(%) HR 3(%)
Isopropyl alcohol 40 50 55
Aloe vera 7.5 7.5 7.5
Hydrogen peroxide 0.125 0.125 0.125
Citric acid 1 1 1
Silver nitrate 0.001 0.001 0.001
Fragrance imparting agent 0.5 0.5 0.5
Distilled water To make up the total volume to 100 ml
[0046] Neat or pre-treatment fingers demonstrated the formation of a bacterial colonies. On a culture plate, HR 1 with a silver nitrate concentration of 0.05% revealed a few colonies of E. coli. HR 2 and HR 3 demonstrated no growth on a culture plate with silver nitrate concentrations of 0.1 and 0.5 % respectively. As a result, a concentration of 0.1% silver nitrate is chosen for further investigation.
EXAMPLE 4
[0047] Table 4 shows the effect of isopropyl alcohol and varying concentrations of silver nitrate while other ingredients remain fixed.
Table 4: Different sanitizing formulations wherein HR1: hand rub 1; HR: hand rub 2; HR3: hand rub 3
Ingredient HR 1(%) HR 2(%) HR 3(%)
Isopropyl alcohol 65 65 65
Aloe vera 7.5 7.5 7.5
Hydrogen peroxide 0.125 0.125 0.125
Citric acid 1 1 1
Silver nitrate 0.05 0.1 0.5
Fragrance imparting agent 0.5 0.5 0.5
Distilled water To make up the total volume to 100 ml
[0048] Neat or pre-treatment fingers showed growth of bacterial colonies. On the culture plate, HR 1 with silver nitrate concentration of 0.05% showed few colonies of E. coli on a culture plate. In comparison, HR 2 and HR 3 with silver nitrate concentrations of 0.1 and 0.5%, showed no growth on a culture plate. Thus, the concentration of 0.1% for silver nitrate was selected for further analysis.
EXAMPLE 5

[0049] Table 5 shows the effect of varying concentrations of isopropyl alcohol while other ingredients remain fixed.
Table 5: Different sanitizing formulations wherein HR1: hand rub 1; HR: hand rub 2; HR3: hand rub 3
Ingredient HR 1(%) HR 2(%) HR 3(%)
Isopropyl alcohol 0.1 60 60
Aloe vera 5 5 5
Hydrogen peroxide 0.125 0.125 0.125
Citric acid 1 1 1
Silver nitrate 0.1 0.1 0.1
Fragrance imparting agent 1 1 1
Distilled water To make up the total volume to 100 ml
[0050] HR 1 contained 50-70 colonies of S. aureus, as well as 5 colonies of E. coli and P. aeruginosa. HR 2 contained 1-2 colonies of S. aureus, while HR 3 had 1-2 colonies of all three bacteria. As a result, a concentration of 65% isopropyl alcohol is chosen for further investigation.
EXAMPLE 6
[0051] Table 6 shows the effect of varying fragrance imparting agent and aloe vera concentration (2.5 and 5%) while other ingredients are unchanged. All the fragrance imparting agent which includes lemongrass, lavender, and tea tree, are individually tested in varying concentrations 0.5%, 1% and 2%
Table 6: Different sanitizing formulations wherein HR1: hand rub 1; HR: hand rub 2; HR3: hand rub 3
Ingredient HR 1(%) HR 2(%) HR 3(%)
Isopropyl alcohol 65 65 65
Aloe vera 5 5 2.5
Hydrogen peroxide 0.125 0.125 0.125
Citric acid 1 1 1
Silver nitrate 0.1 0.1 0.1
Fragrance imparting agent 0.5 1 2
Distilled water To make up the total volume to 100 ml
[0052] The 0.5% and 1% results are equally suitable for all three fragrance imparting agents, lemongrass, lavender, and tea tree. Lemongrass is chosen as a fragrance imparting agent as it is used in aromatherapy to help relieve tension, anxiety, heal wounds, and prevent infection, in addition to being cost-effective.
EXAMPLE 7
[0053] Table 7 shows the effect of varying concentrations of aloe vera while other ingredients are unchanged to examine the skin-friendliness of the sanitizing formulation. All three solutions were found to be microbiologically effective
Table 6: Different sanitizing formulations wherein HR1: hand rub 1; HR: hand rub 2; HR3: hand rub 3
Ingredient HR 1(%) HR 2(%) HR 3(%)
Isopropyl alcohol 65 65 65
Aloe vera 2.5 5 3.5
Hydrogen peroxide 0.125 0.125 0.125
Citric acid 1 1 1
Silver nitrate 0.1 0.1 0.1
Lemongrass 0.5 0.5 0.5
Distilled water To make up the total volume to 100 ml
[0054] For the skin testing of prepared hand rubs, a WHO-based questionnaire is prepared. The questionnaires included questions regarding hand rub: smell, texture, irritation, and drying effect. Participants included Health care workers like doctors, nurses, technicians, office staff, etc. During the experiment, the identities of the hand rubs are hidden from the participants to avoid bias.
[0055] Based on the feedback, products are then assigned a ranking in the following way. Criteria for product acceptability: This was evaluated on a scale of 1 to 7 (1 = Poor; 7 = Excellent). Questionnaire - Part 2 "Product evaluation" – Items Fragrance: 50% above 4. Questionnaire - Part 2 "Product evaluation" – Other items: 75% above 4
Table 8: Evaluation parameters for checking the general acceptability of the solutions HR1, HR2, and HR3.
Tested Parameters Solution A (HR 1) Solution B (HR 2) Solution C (HR 3)
Smell 6.2 6.5 6.1
Texture 5.8 6.8 6.0
Irritation 6 6.7 6
Drying effect 6.3 6.8 6.3

[0056] On checking for skin-friendliness by WHO questionnaire, Solution HR 2 is found to be the best.

[0057] Criteria for skin tolerability: this was evaluated on a scale of 1 to 7 as per WHO guidelines. Questionnaire – Part 2 "Self-evaluation of state of the skin on hands" – all items: 75% above 7 as per WHO guidelines.
Table 9: Evaluation parameters for checking skin tolerability of the solutions HR1, HR2, and HR3
Tested Parameters Solution A (HR 1) Solution B (HR 2) Solution C (HR 3)
Appearance 6.5 6.9 6.3
Intactness 7 7 7
Moisture content 5.8 6.7 6
Sensation 6.4 6.8 6.5

[0058] On the basis of the above feedback, all the three tested hand rubs are acceptable according to WHO criteria (score more than 4). Solution B showed the best results in terms of average score.

Example 10

[0059] Henceforth, solution B (HR 2) was named SRHU hand sanitizer solution B and is further compared with WHO hand sanitizer solution A. Both the solution is then provided to the participants for their feedback, and the results are shown in the table. Solutions B scored better for their skin tolerability. Both solutions A and B were further tested for their skin-friendliness.
Table 10: Evaluation parameters for checking the general acceptability of solutions A and B
Tested Parameters Solution A
(WHO hand sanitizer) Solution B
(SRHU hand sanitizer)
Smell 5.5 6.9
Texture 6.0 6.6
Irritation 6.1 6.8
Drying effect 6.6 6.8

Table 9: Evaluation parameters for checking skin tolerability of the solutions A and B
Tested Parameters Solution A
(WHO hand sanitizer) Solution B
(SRHU hand sanitizer)
Appearance 5.7 6.8
Intactness 6.8 7
Moisture content 5.2 6.9
Sensation 6.5 6.8

[0060] Solutions B scored better for their skin-friendliness. In conclusion, when prepared and tested in accordance with WHO protocol, the formulation of Solution B (SRHU hand sanitizer) based on the evaluation, both solutions Solution A (WHO hand sanitizer) and B fulfilled the criteria but the overall mean score showed solution B to be the better than A.

[0061] Solutions B received better scores for skin friendliness. In conclusion, when prepared and tested in accordance with WHO procedure, the formulation of Solution B (SRHU hand sanitizer) met the criteria, however the total mean score showed that Solution B is preferable to A.

[0062] Various modifications to these embodiments are apparent to those skilled in the art from the description and the accompanying drawings. The principles associated with the various embodiments described herein may be applied to other embodiments. Therefore, the description is not intended to be limited to the 5 embodiments shown along with the accompanying drawings but is to be providing the broadest scope consistent with the principles and the novel and inventive features disclosed or suggested herein. Accordingly, the invention is anticipated to hold on to all other such alternatives, modifications, and variations that fall within the scope of the present invention and appended claims.

I/We Claim:

1) An antimicrobial sanitizing formulation, comprising,
i) isopropyl alcohol in the range of 0.1%- 80% w/w;
ii) an emollient in the range of 0.1%-15% w/w;
iii) hydrogen peroxide in the range of 0.1 0.13% w/w;
iv) citric acid in the range of 0.1% to 2.0% w/w;
v) silver nitrate in the range of 0.1% to 0.5% w/w; and
vi) a fragrance imparting agent in the range of 0.1% to 2.0% w/w.
2) The formulation as claimed in claim 1, wherein said emollient is an aloe vera extract.
3) The formulation as claimed in claim 1, wherein said fragrance imparting agent is selected from a group which may include but not limited to lavender, tea tree and lemongrass.
4) The formulation as claimed in claim 1, wherein said formulation may comprise of elements which may include but not limited to distilled water, essential oils and color imparting agent.
5) The method for preparing said sanitizing formulation as claimed in claim 1, comprises of mixing all said elements in appropriate proportion to obtain a uniform sanitizing formulation.
6) The method as claimed in claim 5, wherein said uniform sanitizing formulation may be used in form of foam, cream, or liquid gel.