Formulation of Herbal Shampoo against Head Louse (Pediculus humanus capitis De Geer)

1. INTRODUCTION

Hair is one of the external indicators of internal body conditions. Shampooing is the most common form of hair treatment [1-3]. For the removal of oil, dirt, environmental pollutants, skin particles, dandruff and other contaminants that gradually grow up in hair, shampoo is used as a cleaning agent and is known as a hair care product being liquidy, creamyorgel-like preparations. The main focus is on the removal of contaminants without any stripping of sebum to make hair unmanageable [4]. The consistency of the preparation is based on the inclusion of natural or synthetic fatty alcohols or the thickening agents (e.g. resin, gum, and PEG) and traditional soaps saturated with glycerides. Indian women use natural herbs such as reetha and shikkakai that are natural cleansing agents without harmful effects.

Nowadays, people are attracted to natural sources as they have no harmful effects as that of synthetic ones. So, natural herbal shampoos are popular among consumers.

The head lice Pediculus humanus capitis De Geer, an ectoparasite, confined to the scalp of hair of humans causes pruritis, skin irritation, and sleep loss as well as occasional secondary bacterial infection [1, 5]. The plant essential oils are used as the best source for insect control due to their bioactive chemicals [1, 6].

The present study deals with the formulations of shampoo and their further characterization, along with the anti-lice activity.

2. MATERIALS AND METHODS

2.5. Evaluation of Formulation

Different formulations of shampoo were evaluated using different parameters such as follows:

Table 2.

S. No.	Ingredients	Batches
		F1	F2	F3	F4	F5	F6	F7	F8	F9
1.	Hydroxypropyl methyl Cellulose (15 cps) (% w/v)	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5
2.	Saponin (Reetha water based) (% w/v)	0.4	0.5	0.6	0.75	-	-	-	-	-
	Reetha (butanol based) (% w/v)	0.4	0.5	0.6	0.75	-	-	-	-	-
3.	Sodium lauryl sulphate (% w/v)	-	-	-	-	0.2	0.2	0.2	0.2	0.2
4.	Glycerine (% w/v)	1.0	1.0	1.0	1.0	1.0	1.0	1.0	1.0	1.0
5.	Neem (water based) (% w/v)	0.5	1.0	1.2	1.5	2.0	-	-	-	-
	Neem (ethanol based) (% w/v)	-	0.5	-	-	1.2	1.2	1.5	-	1.0
6.	Hibiscus (water based) (% w/v)	0.5	1.0	1.0	1.2	1.2	1.0	1.5	1.0	-
	Hibiscus (ethanol based) (% w/v)	-	0.5	0.5	-	-	1.5	1.2	0.5	1.0
7.	Amla (water based) (% w/v)	0.5	-	1.0	1.5	1.0	1.0	1.5	1.5	0.5
	Amla (ethanol based) (% w/v)	-	0.5	1.2	1.0	-	1.2	1.2	1.5	1.0
8.	Henna (water based) (% w/v)	0.5	0.5	1.0	1.0	1.2	1.2	1.5	1.5	0.5
9.	Urad dal (ethanol based) (% w/v)	0.5	-	-	1.2	1.2	-	1.5	1.5	1.0
10.	Distilled Water q.s.	100 ml

2.5.1. Physical Appearance/Visual Inspection

The formulations prepared were evaluated in terms of their clarity, foam producing ability and fluidity [4].

2.5.2. The pH Measurement

The pH was measured using a pH-meter (Model no. µP pH-meter (Decibel)) on the undiluted shampoo. Three determinations were done for each shampoo [4]. For marketed formulation, 10% v/v solution of shampoo was prepared using distilled water and pH was determined.

2.5.3. Viscosity Measurement

The viscosity of 10% v/v shampoo solution (also for marketed shampoo) was measured by using an Ostwald Viscometer as per equation 1, and measurements were performed three times for each shampoo [4]:

(1)

η = Viscosity of solution, t = Time, ρ= Density

2.5.4. Determination of Solid Contents

Percent solid content was measured by taking a weighed clean, dry evaporating dish in which 4 g of shampoo was added. Then the dish and shampoo were weighed again. The exact weight of the shampoo was calculated, and the evaporating dish with shampoo was placed on the hot plate until the liquid portion was evaporated. The weight of shampoo only (solids) after drying was calculated [4].

2.5.5. Dirt Dispersion

To a large test tube containing 10 ml of distilled water, two drops of shampoo were added. One drop of ink was added in the test tube, fitted with a stopcock and shaken ten times. The amount of ink in the foam was estimated as none, light, moderate or heavy [4].

2.5.6. Wetting Time

The canvas was cut into a 3.5 cm diameter disc having an average weight of 0.34 g. The disc was floated on the surface of the shampoo solution (1% w/v) and a stopwatch was started. The time required for the disc to begin to sink was measured accurately and noted as wetting time [4].

2.5.7. Foam Volume

About 20 ml shampoo solution was taken in a measuring cylinder fitted with stopcock and was shaken for 10 sec. Foam volume was then calculated immediately, after 3 min and after 6 min [9].

2.5.8. Surface Tension Measurement

The surface tension of the undiluted shampoo was determined by the drop weight method, using a stalagmometer as per equation 2 [10]:

(2)

Where, δ_sol= Surface tension of solution, δ_H2O= Surface tension of water, m_sol= Weight of drops of solution, m_H2O= Weight of drops of water

The surface tension of marketed formulation was determined by preparing a 10%v/v solution of shampoo using distilled water.

2.5.9. Anti-lice Activity

Anti-lice activity was measured by placing live lice in Petri dish containing 2 ml shampoo. The time of mortality of lice mortality is defined as lack of movement of gut and limbs and failure to respond when the legs were stroked with forceps) was checked and noted [1, 11].

2.5.10. Cleansing Ability

Wool yarn (5 g) was dipped in grease. After that, it was placed in a flask containing 200 ml of water with 1 g of shampoo. The temperature of the water was maintained at 35 ˚C. The flask was shaken for 4 min at the rate of 50 times a minute. The solution was removed and the sample was taken out, dried and weighed. The amount of grease removed was calculated as per equation 3:

(3)

DP is the percentage of detergency power, C is the weight of sebum in the control sample and T is the weight of sebum in the test sample [12].

Table 3.

S. No.	Evaluation Parameters	Batches
		F1	F2	F3	F4	F5	F6	F7	F8	F9
1.	Physical appearance	Light brown	Dark greenish brown	Light greenish brown	Dark brown	Dark brown	Green	Greenish brown	Brown	Greenish brown
2.	pH	5.86 ±0.057	6.06 ±0.057	6.20 ±0.100	6.13 ±0.057	6.03 ±0.057	6.20 ±0.000	6.10 ±0.100	5.93 ±0.152	6.06 ±0.152
3.	Viscosity (cP)	1.05 ±0.011	1.04 ±0.005	0.98 ±0.011	0.98 ±0.00	1.00 ±0.011	1.02 ±0.005	0.99 ±0.03	0.96 ±0.00	0.96 ±0.011
4.	Dirt Dispersion	Light foam	Light foam	Light foam	Light foam	Light foam	Dark foam	Moderate foam	Moderate foam	Light foam
5.	Solid Content (%)	1.74 ±0.042	1.98 ±0.031	2.49 ±0.039	2.72 ±0.049	1.74 ±0.012	2.48 ±0.053	3.25 ±0.045	2.02 ±0.036	1.48 ±0.017
6.	Surface tension (dyne/cm)	39.86 ±7.86	36.83 ±5.47	36.60 ±1.42	40.15 ±7.65	33.05 ±0.86	35.56 ±0.66	34.02 ±0.53	33.41 ±1.19	34.89 ±1.22
7.	Wetting time (sec)	10 ±0.052	8 ±0.049	5 ±0.051	6 ±0.056	8 ±0.051	9 ±0.057	10 ±0.000	7 ±0.012	11 ±0.017

3. RESULTS AND DISCUSSION

Nowadays, natural products are continuously appealing consumers as they are inexpensive, readily available, less toxic, potentially degradable, capable of a multitude of chemical modifications and compatible when compared with synthetic products.

The formulations were tested for pH, viscosity, foam quality, dirt dispersion, % solid content, surface tension, wetting time and anti-lice activity. The results are shown in Table 3.

HPMC base was advantageous over carbopol and xanthan gum; these polymers were of poor grade, so their purity was required for use. For purification, acetone or ethyl alcohol was used, but due to the carcinogenic effect of acetone, ethyl alcohol should be used, but ethyl alcohol is expensive. So, HPMC was used as a base due to its cost-effectiveness.

Water/alcohol-based extract of neem leaves was used for the control of lice because it contains bitter limonoids, which also act as an antidandruff agent. Water/alcohol-based extract of hibiscus leaves was used to stimulate thicker hair growth, prevent premature graying of hair, hair loss, and scalp disorders, and is also used as a conditioner due to its mucilaginous nature. Amla aqueous/alcoholic extract was used for pigmentation of hair, hair growth and nourishment of hair due to the presence of minerals. The use of a combination of the both aqueous and alcoholic extract was found to be beneficial. Water-based extract of henna leaves was used as hair colour due to the chemical interaction of lawsone to the keratin and it is also used as a conditioner. Urad alcoholic extract was used for hair shining (white shine).

A combination of water and butanol extract of reetha was more effective as it had good foaming property along with detergency rather than aqueous or alcoholic extract alone.

The prepared formulations were evaluated for their physical appearance visually for consistency. The evaluation studies revealed that all the formulations had pH range within 5.9-6.2, which was adjusted to pH 7 by adding 0.1N NaOH (sodium hydroxide) dropwise. It influenced the hair quality and tolerance at the skin and eye level. A substance that was too alkaline causing the hair cuticle to open, while a substance that was too acidic causing the cuticle to contract was prone to infection so, the pH was adjusted to neutral. The viscosity of all the formulations of herbal shampoo was such that they could be easily pourable when shaken due to their pseudoplastic nature.

Foam quality of F₅ was found to be of high quality as it produced thick foam amongst all the formulations. The result is shown in Fig. (1).

The dirt should stay in the water, not in the foam, but if the dirt stays in the foam, it would be difficult to rinse and it would redeposit in the hair. The results indicated no dirt in the foam; so F₁, F₂, F₃, F_4, F₅ and F₉ formulations were satisfactory. If the shampoo has high solid content, it will be difficult to properly smudge it into the hair or too hard to wash out. The result of the percent of solid content is tabulated in Table 3 and it was found between 1.48-3.25%. As a result, all the formulations were easy to wash out. Surface tension was measured to find out the cleansing ability of shampoos. If the surface tension is low, the cleansing ability of the shampoo is enhanced in two ways, either facilitating the spread of the aqueous solution and by increasing its wetting ability or by the removal ofdirt from hair by keeping it in the suspension. So, batch F₅ showed good wetting ability due to its reduced surface tension. The wetting time of all the formulations was found to be within 5-11 sec. When the wetting time was reduced, wettability was increased. So, formulation F₃ had good wetting power, whereas formulation F₉ had low wetting power.

The anti-lice activity was assessed by using live lice and the mortality time was measured. Formulation F₂, F₃ and F₆ were prone to cause anti-lice activity leading to their mortality . The results are shown in Table 4.

Cleansing ability was also tested on all the formulations and results are shown in Fig. (2). The cleansing ability was good if it removed dirt and grease from hair easily. So, F₅ had good cleansing action.

Stability studies of shampoo formulations F₁, F₃ and F₅ were carried out for 2 months. During the studies, it was found that the solid content of the formulations was increased. In the context of all other parameters, formulations were found to be stable (Table 5). The prepared shampoo data was compared with the marketed formulation (Vatika Premium Naturals (Henna & Olive) Shampoo). The physical appearance of the marketed shampoo was found to be light green colour with pH 6.1 ± 0.057, while the F5 batch of the prepared shampoo showed brown colour with pH 6.03 ± 0.057. The Vatika premium shampoo showed a viscosity of 0.98 ± 0.011 cP. Both the marketed and the prepared shampoo showed light foam property. The Vatika premium shampoo has solid content 1.94 ± 0.011 (%). The surface tension of the marketed product was found to be 34.05 ± 0.86 dyne/cm. The wetting time of the marketed shampoo was found to be 7 ± 0.051 sec.

CONCLUSION

The study showed that herbal shampoo was successfully formulated using different natural herbal extracts and evaluated using different parameters. The result of the evaluation revealed that all the formulations were of good quality, which were used to clean hair effectively. As they were naturally extracted so, consumer acceptance was increased without any side effect as compared to the synthetic ones. The anti-lice activity was also shown by these formulations and could be used for the same. Formulation F₅ was found to be effective in almost all aspects. In the context of the anti-lice activity, formulations F₂, F₃ and F₆ were effective. The prepared formulations were observed to be comparable to marketed (control) formulation.

REFERENCES