FORMULATION AND EVALUATION OF SOAP BY USING GOAT MILK

International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056

Volume: 13 Issue: 01 | Jan 2026 www.irjet.net p-ISSN: 2395-0072

FORMULATION AND EVALUATION OF SOAP BY USING GOAT MILK

Keerthana Devi N.S1 , Anitha .V2

1 Assistant Professor, Sri Vijay Vidyalaya College of Pharmacy, Dharmapuri,Tamilnadu.

2 B.Pharm, Student, Sri Vijay Vidyalaya College of Pharmacy, Dharmapuri, Tamilnadu.

ABSTRACT- The present study deals with the formulation and evaluation of goat milk soap prepared using natural oils and skin friendly ingredients. The soap was manufactured by the coldprocess method of saponification using coconut oil, olive oil, and castor oil as the base oils, while lavender oil was incorporated for fragrance and therapeutic effect.Goat milk was used instead of water because of its moisturizing, nourishing,and skin-protective properties. Sodium hydroxide pellets were used as the alkaline agent to initiate saponification And special precautions were taken overheating and degradation of goat milk compound.The prepared soap was evaluated for various physical and chemical parameters such as appearance, pH,foam height,moisture content, and cleansing efficiency.The results shows that the goat milk soap possessed good lathering ability, and mild pH and excellent moisturizing properties. The study concludes that goat milk soap formulated with natural ingredients is a cost-effective, ecofriendly,and skin-compatible alternative to commercial available to synthetic soaps.

KEY WORDS: Goat milk soap, saponification, coconut oil, olive oil,castor oil, lavender oil, natural skincare,evaluation of soap

INTRODUCTION:

In recent years, there has been a significant shift in consumer preference toward natural and herbal cosmetic products, driven by increasing awareness of skin health, environmental sustainability, and the potential adverse effects of synthetic chemicals. Conventional soaps and cosmetic cleansers often contain synthetic surfactants, artificial fragrances, preservatives,andcolorantsthatmaycauseskin irritation,dryness,allergic reactions,andlong-term damage, particularlyin individuals with sensitive skin. As a result, natural alternatives derived from plant and animal sources have gained considerable importance in cosmetic science. Among these, goat milk soap has emerged as a popular and effective natural cosmeticpreparationduetoitsmildcleansingaction,excellentmoisturizingability,andskin-nourishingproperties.

Goatmilksoapisatraditionalyetscientificallyvaluableskincareproductthatcombinesthebenefitsofgoatmilkwithnatural vegetableoilsandessential oils.Itsformulationisdesigned tocleanse theskingentlywhilemaintainingitsnatural moisture balance.Unlikesyntheticsoaps,whichoftenstriptheskinofitsnaturaloils,goatmilksoapworksinharmonywiththeskin’s physiology. This makes it particularly suitable for daily use and for individuals suffering from dry, sensitive, irritated, or problem-proneskin.

The uniqueness of goat milk soap lies in the composition of goat milk itself. Goat milk is a rich source of essential nutrients such as vitamins, minerals, proteins, and fatty acids, all of which play a vital role in maintaining healthy skin. It contains vitaminsA,B-complex,D,andE,whichareessentialforskinrepair,nourishment,andprotection.VitaminAsupportsskincell regenerationandhelpsmaintainsmoothandyouthfulskin,whileB-complexvitaminsimproveskintextureandtone.Vitamins D and E contribute to skin hydration and act as antioxidants, protecting the skin from environmental stress and oxidative damage.

Inadditiontovitamins,goatmilkisrichinmineralssuchascalcium,magnesium,potassium,andselenium.Thesemineralsare essential for maintaining skin strength, elasticity, and normal cellular functions. Calcium supports skin cell renewal, magnesium helps reduce inflammation, and selenium provides antioxidant protection. The presence of these minerals enhances the therapeutic and nourishing value of goat milk soap, making it an effective skincare product for various skin conditions.

Anotherimportantcharacteristicofgoatmilkisitshighcontentoffattyacidsandtriglycerides.Thesecomponentsaresimilar tothenaturallipidsfoundinhumanskin,whichallowsgoatmilksoaptopenetratedeeplyandprovidelong-lastinghydration. The fatty acids help repair the skin’s natural barrier, reduce moisture loss, and maintain softness and suppleness. This

International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056

Volume: 13 Issue: 01 | Jan 2026 www.irjet.net p-ISSN: 2395-0072

propertymakesgoatmilksoapespeciallybeneficialforindividualswithdryskin,eczema,psoriasis,andotherskindisorders associatedwithdrynessandirritation

A key component that significantly enhances the cosmetic value of goat milk soap is lactic acid. Lactic acid is a naturally occurringalphahydroxyacid(AHA)presentingoatmilk,knownforitsgentleexfoliatingproperties.Ithelpsremovedeadskin cells from the surface of the skin by loosening the bonds between them, promoting natural skin renewal. Unlike harsh chemical exfoliants, lactic acid provides mild exfoliation without causing irritation or damage to the skin. This gentle action improvesskintexture,brightness,andsmoothness,makinggoatmilksoapsuitableforsensitiveanddelicateskintypes.

Lacticacidalsoplaysacrucialroleinmaintainingtheskin’snaturalpHbalance.HealthyskintypicallyhasaslightlyacidicpH, which acts as a protective barrier against harmful microorganisms and environmental pollutants. Synthetic soaps often disrupt this pH balance, leading to dryness, irritation, and increased susceptibility to infections. Goat milk soap, due to the presence of lactic acid, helps maintain an optimal pH level, thereby supporting the skin’s natural defines mechanism and overallhealth.

Theeffectivenessofgoatmilksoapisfurtherenhancedbytheinclusionofnaturalvegetableoilssuchascoconutoil,olive oil, and castor oil. These oils are commonly used in soap formulation because of their beneficial effects on cleansing, lather formation, moisturizing ability, and skin conditioning. Coconut oil contributes to excellent cleansing action and produces a rich,stablelatherthateffectivelyremovesdirt,excessoil,andimpuritiesfromtheskin.Oliveoilactsasanaturalemollientand moisturizer, nourishing the skin and improving elasticity. Castor oil enhances foam stability and adds softness to the soap, whilealsoprovidingmoisturizingandmildantimicrobialeffects.

In addition to vegetable oils, essential oils such as lavender oil are often incorporated into goat milk soap formulations. Lavenderoiliswidelyrecognizedforitspleasantaroma andtherapeutic properties. Itprovidescalmingandsoothing effects on the skin and mind, making the bathing experience relaxing and refreshing. Lavender oil also possesses antimicrobial, antiseptic,andanti-inflammatoryproperties,whichhelpprotecttheskinfrominfections,reduceredness,andpromotehealing ofminorskinirritations.

Due to its natural composition and balanced formulation, goat milk soap is suitable for a wide range of skin types. It is particularlybeneficialforindividualswithsensitiveskin,asitcleansesgentlywithoutcausingirritationorexcessivedryness. Peoplesufferingfromskinconditionssuchasacne,eczema,dermatitis,andpsoriasismayalsobenefitfromregularuseofgoat milksoap,asithelpssootheinflammation,maintainhydration,andsupporttheskin’snaturalhealingprocess.

Fromtheperspectiveofherbalcosmeticscience,goatmilksoaprepresentsanidealexampleofanaturalcosmeticproductthat combines traditional knowledge with modern scientific understanding. Herbal cosmetics emphasize the use of naturally derived ingredients that are safe, effective, and environmentally friendly. Goat milk soap aligns with these principles by utilizing biodegradable and sustainable ingredients that are gentle on both the skin and the environment. Its formulation avoidsharshchemicalsandsyntheticadditives,makingitasaferalternativetoconventionalsoaps.

Furthermore,thegrowingdemandforeco-friendlyandsustainablecosmeticproductshasincreasedtherelevanceofgoatmilk soap in the cosmetic industry. Consumers are increasingly seeking products that not only enhance beauty but also promote overall skin health and environmental responsibility. Goat milk soap meets these expectations by offering a natural, nourishing,andtherapeuticskincaresolution.

In conclusion, goat milk soap is a valuable natural cosmetic preparation that offers multiple benefits, including gentle cleansing,effectiveminiaturization,mildexfoliation,andtherapeuticeffects.Itsrichcontentofvitamins,minerals,fattyacids, lactic acid, vegetable oils, and essential oils makes it an important product in herbal cosmetic science. The increasing popularity of goat milk soap reflects a broader shift toward natural and holistic skincare approaches, highlighting its significanceinmoderncosmeticformulationandnaturalskincaredevelopment.

BENEFITS OF GOAT MILK SOAP:

 Providesdeepmoistureandpreventsskindryness.

 Helpspreservetheskin’snaturalpHwhilestrengtheningtheprotectiveskinbarrier.

 Gentlyexfoliatestheskinduetolacticacidpresentingoatmilk.

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 Suitableforsensitive,dry,andirritatedskin

 Producesrich,creamy,andstablelather.

 Processes’antimicrobialpropertiesthathelppreventskininfections

 Soothesskinandreducesinflammationandredness

 Helpsinmanagingacneandminorskinproblems

 Improvesskinsoftness,smoothness,andelasticity.

 Providescalmingandrelaxingeffectduetolavenderoilfragrance

INGREDIENTS:

 Goatmilk-Functionsasaskin-conditioningagentwithmoisturizingandnourishingproperties

 Coconutoil -providescleansingactionandgoodlatherformat.

 Oliveoil-Actsasaskinconditionerandemollient.

 Castoroil -Enhancefoamstabilityandsoftnessofthesoap.

 Lavenderoil- -Usedasfragranceandtherapeuticagent

 Sodiumhydroxide -Isusedassaponificationagentinsoappreparation.

 Distilledwater-Usedtodissolvesodiumhydroxidepellets.

EQUIPMENTS:

MeasuringCylinder–foraccuratemeasurementsofliquids,oil,andlyetoreducederrors. Spoon–scrapthesidesandbottomofthemixingbowl,tohandlesmallquantitiesofingredients. Moldingandcurving–createsoapbarswithspecificshapes,sizes,anddesign.

Thermometer–Isusedtomonitortemperatureofboththelyesolutionsandoils. Mixingbowl–usedtomixthelyewithwater,goatmilkandotheringredients.

Blender–utilizetothoroughlycombineoils,fats,andlye,tocreateauniformmixture. Grouse, mask,Goggles – prevent skincontact withlye(sodiumhydroxide),whichcancausesevere skin irritation, burns,and otherinjuries.

METHODS OF PREPARATION:

1. Preparation of lye solution:

 Dissolvesodiumhydroxidepelletsindistilledwater.

 Coolthesolutiontoavoidoverheating.

 Thelyegoatmilksolutionsareslowlyaddedtofreshgoatmilkwithcontinuousstirringwithcompletelydissolved.

International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056

Volume: 13 Issue: 01 | Jan 2026 www.irjet.net p-ISSN: 2395-0072

2. Preparation of oil phase:

 Oils such as coconut oil, olive oil, and castor oil are weighed accurately and gently heated to melt and mix uniformly.

3. Mixing:

 Thelye–goatmilksolutionisslowlyaddedtotheoilmixturewithconstantstirringorblendinguntiltraceisachieved

4. Addition of additives:

 Lavenderessentialoilisincorporatedintothemixtureandblendeduniformly.

5. Molding and curing:

 Thepreparedsoapmassistransferredintomolds,keptundisturbedfor24-48hours,andthenremolded.Andcuredfor 3-4weekspriortouse.

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Fig no: 04 molding and curing

Table no 01 ; FORMULATION:

Thegoatmilksoapwasformulatedusingcoconutoil,oliveoil,andcastoroilsthebaseoils,lavenderoilsasafragrance andsoothingagent,goatmilkasanaturalmoisturizer,andsodiumhydroxideasthesaponificationagent S.NO INGREDIENTS

FORMULATION(1)

Fig no :05 Goat milk soap formulation(1)

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International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056

Volume: 13 Issue: 01 | Jan 2026 www.irjet.net p-ISSN: 2395-0072

FORMULATION (2)

FORMULATION(3)

EVALUATION TEST FOR GOAT MILK SOAP:

1. Physical appearance:

EvaluatedforColor,Odor,and,surfacetexture.

Soapshouldbeuniforminappearance.Freefromcracksandairbubbles.

2. pH test:

ThepHvalueofa1%soapsolutionisdeterminedwiththehelpofapHmeter IdealpHrange7-10 GoatmilksoapusuallyshowsamildpH,suitableforskin.

3. Foaming ability and foam stability:

Soapsolutionisshakeninmeasuringcylinder. Foamvolumeismeasureimmediatelyafter5minutes. Goodsoapsshowstableandsufficientfoam.

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4. Moisture content:

Determinedbydryingaweighedsampleinahotairoven. Lowmoisturecontentimprovesshelflifeandhardness

5. Hardness test:

Evaluatesresistancetopressureorbreak. Hardsoapensureslongerdurabilityduringuse.

6. Cleansing test:

Testbywashingoilysubstancefromasurface. Indicatesthedetergentefficiencyofthesoap.

7. Skin irritation test:

Soapappliedonasmallskinarea. Observedforredness,itching,orirritation. Goatmilksoapisgentlynon-irritant.

8. Total fatty matter:

Measuresthepercentageoffattysubstance. HigherTFM=betterqualityandmoisturizingeffect.

9. Free alkali test:

Determinespresenceofunreactedsodiumhydroxide. Excessalkalicancauseskinirritation.

10. Stability study:

Soapstoredatdifferenttemperature. ObservedforchangesinColor,Odor,andTexture.

Table no : 02 RESULTS:

S.NO

PARAMETERS

RESULTS

1. COLOUR CREAMYOFFWHITE

2. Odor PUNGENT 3. APPEARANCE GOOD

TEXTURE SOLIDANDSMOOTH

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CONCLUSION:

From the evaluation studies, it can be concluded that goat milk soap prepared using natural oils exhibits good physicochemical properties, acceptable pH, adequate foaming ability, and high fatty matter, indicating good cleansing and moisturizing effect. The soap showed satisfactory hardness, low free alkali content, and no signs of skin irritation, making it safeforregularuse.Stabilitystudiesrevealednosignificantchangesinappearanceorodorduringstorage.Overall,goatmilk soapcanbeconsideredamild,skin-friendlyandeffectivecosmeticproductsuitablefordailypersonalcare.

REFERENCE:

1. Barel,A.O.,PAYE,M.,&Maibach,H.I.Handbookofcosmeticscienceandtechnology.3rded.,CRCPress,newYork,2009.

2. Butler,H.Poucher’sPerfumes,cosmeticsandSoaps.10th ed.,Springer,Dordrecht,2000.

3. Cavitch,S.M.TheSoapmaker’scompanion.Storeypublishing,USA,1997.CASQ

4. Draelos,Z.D.CosmeticDermatology:ProductsandProcedures.Wiley-Blackwell,2010.

5. FDA.CosmeticProductsGuidanceandRegulations.U.S.FoodandDrugAdministration,2018.

6. Harry,R.G.Harry’scosmeticology.8th ed.,ChemicalPublishingCo.,newYork,2000.

7. Kumar,V.,Abbas,A.K.,&Aster,J.C.RobbinsBasicPathology.9th ed.,Elsevier,2013.

8. Mitsui,T.Newcosmeticscience.Elsevierscience,Amsterdam,1997.

9. Sharma ,P.P. Cosmetics- Formulation, Manufacturing and Quality Control.4th ed., Vandana publications, new Delhi, 2005.

10. Wilkinson,J.B.,&Moore,R.J.Harry’sCosmeticology.7th ed.,LongmanScientific&Technical,UK,1982.

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