Formulation and evaluation of antibacterial herbal deodorant stick

Deodorant products inhibit the growth and activity of bacteria that degrade the apocrine gland in the armpit. Despite their effective antibacterial properties, common antibacterial agents such as triclosan and aluminum salts increase the risk of Alzheimer's disease, breast and prostate cancer, and contact dermatitis. As a consequence, plant extracts with antibacterial properties are useful. This research study was carried out by opting the Sunflower wax, Virgin coconut oil, Rosemary oil & Lavender oil. Rosemary oil & Lavender oil are reported to possess antibacterial activity. Herbal deodorant sticks were prepared and characterized for physical observations, pH measurement, softening point test (Softening time), breaking load test (Breaking point test), spreadability, stability test and antibacterial study. The prepared sticks were also compared with two different Marketed Deodorant Sticks. The result data shows that prepared herbal deodorant stick is equally stable in comparison with marketed deodorant sticks and has shown significantly comparable antibacterial effect.


Introduction
Deodorant sticks are used to control body odor.These products are made by blending active ingredients with waxes, oils, and silicones and molding the mixture into stick form.Body odor is primarily generated in the area under the arms where there is a high concentration of sweat glands.While sweat from these glands is initially odorless, it contains natural oils, called lipids, that provide a growth medium for bacteria living on the skin.These bacteria interact with the lipids, converting them into compounds that have a characteristic sweaty odor.Isovaleric acid, for example, is one chemical compound that gives sweat its smell.Odor control can be achieved by various means -basic hygiene (washing with soap and water) is the most important but also by antiperspirant, fragrances or any combination of these.Basically, deodorants and antiperspirants are two different ways to prevent odor.Deodorants are perfumed preparation, which mask but do not actually affect perspiration, it can also work by creating a more acid, inhospitable environment to odorproducing bacteria, while antiperspirants clog or block the pores, cutting down on the amount of perspiration that leaves the body, thus giving the bacteria less to feed on [1,2].
Natural deodorants are the modern trend in the field of beauty and fashion.These agents are gaining popularity as nowadays most people prefer natural products over synthetic materials for their personal care to enhance their beauty as these products supply the body with nutrients and enhance health and provide satisfaction as these are free from synthetic chemicals and have relatively less side-effects compared to synthetic cosmetics [3].Natural Deodorants are a great way to avoid parabens, aluminum, and neuro-toxins found in commercial deodorants and antiperspirants [4,5].This research study was carried out by selecting the Rosemary oil & Lavender oil [6] which was reported to have antibacterial activity.

Method of Preparation of Herbal Deodorant Stick (HDS)
Sunflower wax was taken in a china dish and placed into water bath which was set to 75 °C, for 4 -5 minutes.Careful attention was paid to this process to ensure that the temperature is not too high.Quick melting was ensured & to avoid charring.On confirming the complete melting of sunflower wax, it is removed from water bath; virgin coconut oil, lavender oil and rosemary oil were added drop wise and mixed well (table 1).The solution was poured into the pre lubricated container & allowed to settle for 24hours.Different concentration of sunflower wax was used to check its physical stability.

Physical stability of the sunflower wax
In order to become better acquainted with sunflower wax, an experiment was conducted.The wax was melted in varying ratios with virgin coconut oil in a water bath, swirled to combine the melted mixture and let them sit overnight to set up.The next day it was poked, scraped, squished, and examined.When looking at the ratios, the first number is the sunflower wax, the second is the coconut oil, so 1:2 is 1 part wax to 2 parts oil, while 1:5 is one part wax to five parts coconut oil (by weight).

Antibacterial activity of formulated Herbal Deodorant Stick
The agar-well diffusion standard cup plate technique was used to determine the antimicrobial activity by using sabouraud's dextrose agar [Hi-media].The melted media was seeded with the suspension of microorganisms and allowed to solidify.The formulations were aseptically transferred to the Hi-media in Petri-dish with the help of sterile forceps.The formulated herbal deodorant stick was kept for incubation in an incubator at 30˚C for 5-7 days.The assessment of antimicrobial activity was based on the measurement of the diameter of the zone of inhibition in mm [9].

Results and discussion
From the experiment where the wax was melted in the varying ratios with coconut oil, it was found that at lower concentrations, more creaminess was produced, that settles into long -lasting skin tackiness.Hence, it was concluded that HDS 3 was optimum i.e with

Physical observation of HDS and MDS
Physical observation of HDS 3, MDS 1 and MDS 2 were studied and the results are tabulated in table 2. The results indicate that the formulated HDS 3 had compatible physical observation which was comparable with that of the MDS 1 and MDS 2. In fact the HDS3 had pleasant odour when compared to the MDS 1 and MDS 2 which had strong odour.

Evaluation of pH
The pH of HDS3, MDS1 and MDS2 was found to be from 6 to 8 which are suitable for the human skin and non-irritant upon application (Table 3).

Evaluation of Softening point
The softening point is of interest in hot climate especially during handling, storage and display in pharmacy window.Table 4 shows the softening point of HDS3 which was comparable to the commercial MDS1 and MDS2 formulation.

Evaluation of Breaking point
Breaking point was done to determine the strength of deodorant stick.The weight was gradually increased by a specific value (10 gm) at specific interval of 30 second and weight at which breaks was considered as the breaking point.The result of breaking point is displayed in table 5.

Evaluation of Spreadability
Spreadability of HDS 3, MDS 1 and MDS 2 was tested and found to have excellent spreadability which are tabulated in table 6.

Stability test
Sweating is an excess of oil or solvent occurred onto the surface of the deodorant sticks.Sweating can be seen clearly if the sample is unstable.Table7 shows that all the sticks were stable upon storage for 2 weeks at room temperature.

Antibacterial activity of formulated Herbal Deodorant Stick
The antibacterial activity of Herbal Deodorant Stick was studied.The results obtained from the studies were shown in figure 1 as well as in table 9.The zone of inhibition for HDS and MDS formulations were calculated.HDS 3 formulation showed a maximum zone of inhibition than MDS 1 and MDS 2 formulation.A significant result was obtained for HDS formulation against Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli, which were found to be 14mm, 18mm, and 16 mm respectively due to the synergistic effect produced in the HDS 3 formulation, which showed significant zone of inhibition and acts effectively against bacteria on the skin.

Conclusion
An herbal antibacterial deodorant stick was formulated using sunflower wax, virgin coconut oil, lavender oil & rosemary oil.It was evaluated with various in-vitro evaluation parameters like physical observation, pH, softening point, breaking point, spreadability& stability.Two Marketed deodorant sticks were considered and subjected to the similar in vitro evaluation parameters as that of the prepared herbal deodorant sticks.The results obtained from the research study shows that prepared herbal deodorant stick (HDS 3) is equally stable in comparison with marketed deodorant sticks (MDS 1 & MDS 2).It has also shown significantly comparable antimicrobial effect, although further studies are required to scale up the preparations & evaluate accordingly.

Disclosure of conflict of interest
No conflicts of interest.

Table 1
Composition of the different formulation 1:8 ratio of sunflower wax & virgin coconut oil.Physical Observations, pH Measurement, Softening Point Test (softening time), Breaking load test (breaking point test), spreadability, Stability test and Antibacterial study of HDS 3 were carried out using standard protocols and compared with two different Marketed Deodorant Sticks (MDS 1 & MDS 2).From results data, it shows that prepared herbal deodorant stick is equally stable in comparison with marketed deodorant sticks and has shown significantly comparable antibacterial effect (Table 2-9).

Table 2
Physical observation of HDS and MDS

Table 3
Evaluation of pH

Table 4
Evaluation of softening point

Table 5
Evaluation of Breaking point

Table 6
Evaluation of Spreadability

Table 7
Stability test

Table 8
Comparison of Physical characteristics of HDS3 with marketed products