Nail lacquersA compilation by Jolly R Parikh

Nail polish• Nail polish is actually a misnomer

(wrong name) for nail care products since no actual polishing is involved in the application.

• The product is composed of dissolved resins and dries to a hard glossy coat.

• So technically the correct name is Nail lacquer.

• However the terms nail polish, nail enamel, nail varnish, nail paint and nail lacquer are used interchangeably.

• These products are applied by painting the nail with a brush.

Nail lacquers• In best manicure practices:• First a base coat is applied,

followed by two coats of coloured nail lacquer and finally a top coat layer.

• The base coat: increases adhesion of coloured nail lacquer to the nail while the Top Coat: increases the chip resistance characteristic of nail lacquer.

Formulation1. Resins2. Solvents3. Plasticizers4. Colorants5. Thixotropic agents6. Colour stabilizers By law all ingredients must be

displayed on the product packaging by means of international nomenclature for cosmetic ingredients (INCS)

FormulationA. Resins hold the ingredients of the

lacquer together while forming a strong film on the nail.

• Resins are polymers which are long chain molecules solid and gummy in the pure state.

• Two types of resins are used:1. Hard Glossy resins which give the

lacquered nail its desired appearance e.g. Nitrocellulose, methacrylate polymers or co polymers.

2. Soft Pliable resins which enhance adhesion and flexibility e.g. Tosylamide ,formaldehyde resins, polyvinyl butyral, polyester resins.

FormulationB. Solvents are the carriers for

lacquers. • They must dissolve the resin,

suspend the pigments and evaporate leaving a smooth film.

• The drying speed must be controlled to prevent bubbling and skinning.

• Optimum drying rate requires a blend of solvents.

• All solvents have a dehydrating and defatting action on the skin.

• e.g. Ethyl acetate, isopropyl alcohol, N-butyl acetate

FormulationC. Plasticizers keep the resins flexible

and less likely to chip e.g. Camphor, dibutyl phthalate [DBP]. Europe maintains its ban on DBP. Hence other plasticizers used are triphenyl phosphate, trimethyl pentanyl diisobutyrate, acetyl tri butyl citrate.

D. Colorants are used in the lake form. Organic colorants are adsorbed or co precipitated on inorganic substrates such as silicates, oxides.

A Shimmer effect is created by minerals like mica, aluminium flakes.

Formulation• Colorants As per the INCI

convention colorants are labelled by their international colour index CI numbers.

Colour Index number Colour

77891 Titanium dioxide

60725 D & C Violet # 2

15850 D & C #6, D & C #7

FormulationE. Colour Stabilizers:

Benzophenone -1 and etocrylene are added to prevent shifting of colour upon exposure to UV light. They are better known as sun screens since they protect the colour.

F. Thixotropic agents: Provide flow control and keep the colorants dispersed e.g. Clay derivatives like Stearlkonium bentonite or hectorite.

Antifungal agents are added for therapeutic purposes.

Evaluation of nail lacquers1. Colour2. Surface shine or gloss3. Application4. Viscosity5. Drying Time6. Non volatile content

Evaluation of nail lacquers1. Colour of each batch is checked

by comparing it with master colour standard.

2. Surface shine or gloss: is determined visually.

3. Application is tested by evenness, smoothness of brushing and streaking.

4. Viscosity: is determined by Brookfield viscometer.

Evaluation of nail lacquers5. Drying Time: Apply a thin film of

the sample with a 0.006” applicator under controlled conditions of temperature and humidity at 25 ̊C & 50% RH to a completely nonporous glass plate or melamine coated paper.

• Note the time required to form a dry to touch film.

• Dry to touch is a condition in which a film may be touched with a clear finger tip without transfer of any material to the tip.

Evaluation of nail lacquers6. Non volatile content: • 1-2 g of the sample is placed in a

flat tarred dish. • Sample is spread and the dish

placed in the oven at 105 ̊±2 ̊C for 1 hour.

• Remove the dish and weigh. • Reheat for 1 hr and reweigh.• The greater weight loss value is

used to calculate non volatile content

Thank You..!!