- A preview of this full-text is provided by Springer Nature.
- Learn more
Preview content only
Content available from Biomass Conversion and Biorefinery
This content is subject to copyright. Terms and conditions apply.
ORIGINAL ARTICLE
Green soap formulation: an insight into the optimization
of preparations and antifungal action
Arunachalam Thirunavukkarasu
1
&Rajarathinam Nithya
1
&Raja Sivashankar
2
&Arunachalam Bose Sathya
3
&
Selvasembian Rangabhashiyam
4
&Sivanantham Arul Pasupathi
1
&Murugan Prakash
1
&Mayilvahanan Nishanth
1
Received: 6 August 2020 /Revised: 25 September 2020 /Accepted: 16 October 2020
#Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract
Ultrasound-assisted extract of Acalypha indica was used to prepare the green soap formulation. Previously, D-optimal mixture
design was used to optimize the mixture of oil components including coconut oil (A, 34–56%), soybean oil (B, 19–31%), castor
oil (C, 14–23%), sunflower oil (D, 4–6%), and olive oil (E, 5–9%). Linear regression models were proposed to predict the
responses, i.e., hardness (Y
1
), iodine (Y
2
), and iodine number saponification (INS) (Y
3
), and validated with a high degree of
statistical accuracy (F
cal
>F
tab
;df=4,p<0.0001;R
2
> 0.9950). Optimization results revealed that the formulation containing
44.57% A, 23.62% B, 17.44% C, 5.37% D, and 9.0% E would yield 41 Y
1
,62Y
2
, and 159 Y
3
. The chemical properties of the
optimized soap formulation were quite comparable concerning the standard soap specifications (IS13498). Further, this formu-
lation was supplemented with Acalypha indica extract to prepare the green soap, and its antifungal activity was determined using
the agar dilution method.
Keywords Green soap formulation .Acalypha indica .D-optimal mixture design .Antifungal activity
1 Introduction
Cosmetics are the range of products that are used to enhance the
personal appearance or the physical appeal of an individual [1].
Mostly, these cosmetics are categorized into skincare, hair care,
perfumes, deodorants, personal care, and oral cosmetics. In the
modern era, the use of these items is inevitable in the routine
life of every individual, and hence, the markets for such cos-
metic products are in the exponential phase. According to the
recent report, the global market value of cosmetics was about
507.8 billion US dollars in 2018 and it is expected to increase to
about 758.4 billion US dollars by 2025 [2]. Among them,
skincare tops the list contributing to about 39% of the total
market size [3]. However, the various chemicals used in the
preparation of skincare formulations might cause ill effects
ranging from mild allergic reactions to carcinogenicity [4].
For instance, the use of debenzoylmethanes, paraaminobenzoic
acid (PABA), and cinnamates in sun-screen products are capa-
ble of causing photoallergic dermatitis [5]. Likewise, the use of
butylated hydroxyl anisole (BHA) and butylated hydroxyl tol-
uene (BHT) in moisturizers and lipsticks were identified as the
potent carcinogen and endocrine disruptors. Further, FDA
banned the use of antibacterial soap formulations having the
list of 19 different chemicals (Table 1) as these chemicals were
failed to prove them as Generally Recognized As Safe and
Effective (GRAS/GRAE) [6]. Hence, the formulation scientists
in the cosmetics fields are highly focusing on developing a
wide range of green-based products with no or minimal use
of these hazardous chemicals.
Soaps are one of the skincare products that can be defined
as the cleansing agent produced by the saponification reaction
of oils and fatty acids in presence of sodium or potassium
hydroxide (lye solution) [7]. Soaps are amphipathic in nature,
consisting of polar ionic hydrophilic head molecules and non-
polar hydrophobic tail molecules. In dissolution with water,
these soap molecules get arranged themselves as spherical
aggregates called micelles. These micelles have the water-
*Arunachalam Thirunavukkarasu
thiru@gct.ac.in
1
Department of Industrial Biotechnology, Government College of
Technology, Coimbatore, India
2
Department of Chemical Engineering, Hindustan Institute of
Technology and Science, Chennai, India
3
Department of Biotechnology, Aarupadai Veedu Institute of
Technology, Chennai, India
4
School of Chemical and Biotechnology, SASTRA University,
Thanjavur, India
https://doi.org/10.1007/s13399-020-01094-1
/ Published online: 21 October 2020
Biomass Conversion and Biorefinery (2023) 13:299–310
Content courtesy of Springer Nature, terms of use apply. Rights reserved.