Introduction
Herbal cosmetics are preparations that use plant-derived ingredients for both therapeutic and cosmetic purposes. This chapter covers six major herbal cosmetic agents — their sources, chemical constituents, commercial preparation methods, and their therapeutic and cosmetic uses.
1. Aloe Vera Gel
Family: Liliaceae Source: Mucilaginous tissue located in the leaf parenchyma (inner gel) of Aloe species.
Chemical Constituents
Barbaloin, Aloesin, Anthraquinone glycosides, Aloe-emodin-anthrone, Chrysophanic acid, Choline salicylate, Saponins.
Therapeutic Uses
- Used as an irritant purgative and for digestive health improvement
- Promotes oral health
- Clears acne and relieves anal fissures
- Treatment of radiation burns
Cosmetic Uses
- Relieves skin pain and itching
- Used in skin cosmetics as a protective agent
- Anti-wrinkle properties
- Used in ointments and creams to assist healing of wounds, burns, eczema, and psoriasis
Commercial Preparation
Compound Benzoin Tincture (Friar’s Balsam) — consists of benzoin, prepared storax, balsam of tolu, aloes, and 90% alcohol.
Aloe vera gel extraction process:
- The bottom of the leaf is cut off and leaves are left to “bleed,” allowing the bitter aloin to drain out (aloin must be removed for a quality, non-laxative gel product).
- The gel is removed from the leaf, filtered, homogenised, pasteurised, and stabilised.
- Finally, the gel is concentrated.
- The entire process from cutting the leaves to the final extract must be completed within a maximum of 2 days to prevent quality loss.
- The concentrated gel is then sold to end consumers or to herbal product industries.
2. Almond Oil
Source: Fixed oil obtained by expression from the seeds of Prunus amygdalus.
Chemical Constituents
- Fixed oil (40–50%), protein (20%), enzyme emulsin, bitter glycoside amygdalin (1–3%), volatile oil (0.5%)
- Amygdalin yields benzaldehyde and hydrocyanic acid upon hydrolysis
- Bitter almond oil contains 80% benzaldehyde and 2–6% hydrocyanic acid
Therapeutic Uses
- Treatment of inflammation
- Assists immune function
- Supports wound healing
Cosmetic Uses
- Treatment of acne
- Excellent moisturising properties
- Used in lipstick and skin cleansing products
- Used for earwax softening and ear cleaning
Commercial Preparation
- Almonds are harvested before the autumn rains (August–September).
- De-hulling — the mesocarp (outer husk) is removed.
- Drying — nuts are sun-dried for 2–3 days or subjected to hot air ventilation, reducing humidity content to 5–8%.
- Cracking — the shell is separated from the seed.
- Oil extraction — seeds are ground and the oil is extracted; this generates a solid edible by-product.
- Key optimisation points for quality are the drying and extraction stages.
3. Lavender Oil
Source: Essential oil obtained by distillation from the flower spikes of certain lavender species.
Chemical Constituents
Linalool, Linalyl acetate, Lavandulyl acetate, Eucalyptol, Terpineol, Ocimene, Terpinen-4-ol.
Therapeutic Uses
- Promotes relaxation
- Used to treat anxiety, fungal infections, allergies, depression, insomnia, eczema, nausea, and menstrual cramps
Cosmetic Uses
- Kills bacteria — prevents and heals acne breakouts
- Treats psoriasis
- Cleanses skin and reduces redness and irritation
Commercial Preparation
- Harvest — Cut and dry enough lavender to make at least 1 oz of dried lavender. Hang cut flowers upside down in a dry, dark place for 2–4 weeks.
- Infuse — Pour coconut oil over the dried lavender in a clean glass jar until fully covered. Seal tightly, shake well, and store near a window (not in direct sunlight) for 7–10 days, shaking daily.
- Strain — Strain through a cheesecloth or strainer into a clean glass jar. Store in a cool, dark place. The oil keeps for up to 1 year.
4. Olive Oil
Family: Oleaceae Source: Fixed oil expressed from the ripe fruit of Olea europaea Linn.
Chemical Constituents
Triglycerides mainly in the form of Olein, Palmitin, and Linolein.
Therapeutic Uses
- Used as a nutrient, demulcent, and mild laxative
Cosmetic Uses
- Softens skin and crusts in eczema and psoriasis
- Used as an ingredient in earwax-softening preparations
Commercial Preparation
- Prepared by crushing and pressing ripe olives
- The entire olive contains 20–30% oil; the fruit pulp contains 60–80% oil
5. Rosemary Oil
Family: Lamiaceae Source: Distilled from the flowering tops of leafy twigs of Rosmarinus officinalis.
Chemical Constituents
p-Cymene, Linalool, Gamma-terpinene, Thymol, Beta-pinene, Alpha-pinene, Eucalyptol. The oil consists of monoterpenic hydrocarbons, oxygenated monoterpenes, and sesquiterpene hydrocarbons.
Therapeutic Uses
- May improve memory in young adults when taken orally
- May help relieve pain
- Reduces joint inflammation
Cosmetic Uses
- Stimulates hair growth
- Deeply hydrates skin — can be used as a moisturiser
- Anti-bacterial and anti-inflammatory properties help battle acne
- Reduces the appearance of blemishes and lightens stretch marks
6. Sandalwood Oil
Family: Santalaceae Source: Obtained by distillation of sandalwood — Santalum album Linn.
Chemical Constituents
- The main odorous and medicinal constituent is santalol — a primary sesquiterpene alcohol forming more than 90% of the oil.
- Present as a mixture of two isomers — α-santalol (predominant) and β-santalol.
- Other constituents: santene, nor-tricycloekasantalene, α- and β-santalenes.
Therapeutic Uses
- Demonstrated chemoprotective action on liver carcinogenesis in animal studies
- Used for symptomatic treatment of dysuria (pain or discomfort during urination)
Cosmetic Uses
- Highly valued in perfumery creations
- Important ingredient in soaps, face creams, and toilet powders
Commercial Preparation
- Sandalwood trees must be a minimum of 15 years old (for S. album) before they can be harvested, as the oil develops in the heartwood over time.
- The older the tree, the higher the proportion of heartwood — and thus the higher the oil content.
- Because the oil is held tightly within the wood, a steam distillation process is required. The wood is first ground to powder form.
- Steam heated to approximately 140–212°F is passed through the powdered wood.
- The steam releases the essential oil locked within the cellular structure of the wood.
- The mixture of steam and oil passes through a condenser and cools, separating into a layer of oil and a layer of water (hydrosol).
- The sandalwood essential oil rises to the top and is collected.
Quick Comparison Table
| Oil | Plant Source | Key Chemical | Primary Cosmetic Use |
|---|---|---|---|
| Aloe Vera Gel | Aloe barbadensis | Barbaloin, Aloesin | Anti-wrinkle, wound healing |
| Almond Oil | Prunus amygdalus | Amygdalin, fixed oil | Moisturising, acne treatment |
| Lavender Oil | Lavandula spp. | Linalool, Linalyl acetate | Acne, skin cleansing |
| Olive Oil | Olea europaea | Olein, Palmitin | Skin softening, eczema |
| Rosemary Oil | Rosmarinus officinalis | α-Pinene, Eucalyptol | Hair growth, acne |
| Sandalwood Oil | Santalum album | α-Santalol, β-Santalol | Perfumery, face creams |
D.Pharma 1st Year — All Subjects Notes
D.Pharma 2nd Year — All Subjects Notes