L'olio di ricino è un olio vegetale estratto dai semi della pianta di ricino (Ricinus communis). È ampiamente utilizzato per le sue varie applicazioni terapeutiche, cosmetiche e industriali grazie alle sue proprietà uniche.

Composizione Chimica e Struttura:

L'olio di ricino è composto principalmente da:

• Acido Ricinoleico: Il principale acido grasso dell'olio di ricino, che costituisce circa il 90% degli acidi grassi presenti. Ha proprietà uniche che contribuiscono ai benefici medicinali e cosmetici dell'olio.
• Altri Acidi Grassi: Include acido oleico, acido linoleico e acido palmitico, che contribuiscono al profilo complessivo degli acidi grassi dell'olio.
• Gliceridi: Gli acidi grassi sono esterificati con il glicerolo, formando trigliceridi.

Proprietà Fisiche:

• Aspetto: Liquido chiaro o giallo pallido
• Odore: Lieve, caratteristico dei semi di ricino
• Texture: Viscoso e denso, con una leggera sensazione appiccicosa

Processo di Produzione:

La produzione dell'olio di ricino comprende:

1. Raccolta: I semi di ricino vengono raccolti dalla pianta di ricino.
2. Estrazione: I semi vengono sottoposti a pressione meccanica o estrazione con solventi per ottenere l'olio.
3. Raffinazione: L'olio grezzo viene raffinato per rimuovere impurità e migliorare chiarezza, stabilità e sicurezza.

Applicazioni:

• Mediche: L'olio di ricino è utilizzato come lassativo e per le sue potenziali proprietà antinfiammatorie e antimicrobiche. È anche impiegato in alcune formulazioni terapeutiche per condizioni della pelle e dolori articolari.
• Cosmetiche: Nella cura della pelle, l'olio di ricino è apprezzato per le sue proprietà idratanti, emollienti e anti-infiammatorie. Si trova in creme, lozioni, balsami per le labbra e prodotti per i capelli per migliorare idratazione e morbidezza.
• Altre: L'olio di ricino è utilizzato anche in applicazioni industriali, inclusa la produzione di lubrificanti, rivestimenti e polimeri grazie alle sue proprietà chimiche uniche.

Considerazioni Ambientali e di Sicurezza:

L'olio di ricino è generalmente considerato sicuro per l'uso e biodegradabile. Tuttavia, è importante garantire che l'olio sia ottenuto in modo sostenibile e sia privo di contaminanti. L'olio di ricino può causare reazioni allergiche o irritazioni cutanee in alcuni individui, quindi è consigliabile effettuare test di sensibilità quando utilizzato in cosmetici.

Bibliografia__________________________________________________________________________

Sandford EC, Muntz A, Craig JP. Therapeutic potential of castor oil in managing blepharitis, meibomian gland dysfunction and dry eye. Clin Exp Optom. 2021 Apr;104(3):315-322. doi: 10.1111/cxo.13148. Epub 2021 Mar 10. PMID: 33037703.

Abstract. The multifactorial pathogenesis and interrelationship of blepharitis, meibomian gland dysfunction and dry eye disease poses challenges to any therapeutic approach. Current treatments are mostly palliative, with success limited by perceived inefficacy and poor patient compliance. Castor oil, a natural derivative of the Ricinus communis plant, is widely used as an emollient in cosmetics and personal care products, drug delivery systems and wound dressings. Castor oil is deemed safe and tolerable, with strong anti-microbial, anti-inflammatory, anti-nociceptive, analgesic, antioxidant, wound healing and vaso-constrictive properties. Its main constituent, ricinoleic acid, has a bipolar molecular structure that promotes the formation of esters, amides and polymers. These can supplement deficient physiological tear film lipids, enabling enhanced lipid spreading characteristics and reducing aqueous tear evaporation. Studies reveal that castor oil applied topically to the ocular surface has a prolonged residence time, facilitating increased tear film lipid layer thickness, stability, improved ocular surface staining and symptoms. This review summarises the properties, current uses of, and therapeutic potential of castor oil in managing ocular surface disease. The biochemical, medicinal actions of castor oil are explored from the perspective of ocular surface pathology, and include microbial and demodectic over-colonisation, inflammatory and oxidative processes, as well as clinical signs and symptoms of dryness and discomfort.

McKeon TA, Lin JT, Stafford AE. Biosynthesis of ricinoleate in castor oil. Adv Exp Med Biol. 1999;464:37-47. doi: 10.1007/978-1-4615-4729-7_4.

Abstract. Castor oil is 90% ricinoleate (12-hydroxyoleate) and has numerous industrial uses. Components of castor bean (Ricinus communis L.) pose serious problems to processors. Other researchers have cloned the gene for the oleoyl hydroxylase, but transgenic plants produce only about 20% hydroxy fatty acid. To improve such transgenic substitutes for castor, we are using HPLC analysis of castor bean microsomal suspensions to follow the hydroxylase reaction and the movement of 14C-ricinoleate through phospholipid into triacylglycerol. Most labeled ricinoleate is rapidly removed from the phospholipid fraction as free fatty acid and incorporated into triacylglycerol, with triricinolein predominating. Elucidation of the basis for high incorporation of ricinoleate and exclusion of oleate from triacylglycerols will identify genes that can be used to engineer high ricinoleate production in transgenic plants.

Final report on the safety assessment of Ricinus Communis (Castor) Seed Oil, Hydrogenated Castor Oil, Glyceryl Ricinoleate, Glyceryl Ricinoleate SE, Ricinoleic Acid, Potassium Ricinoleate, Sodium Ricinoleate, Zinc Ricinoleate, Cetyl Ricinoleate, Ethyl Ricinoleate, Glycol Ricinoleate, Isopropyl Ricinoleate, Methyl Ricinoleate, and Octyldodecyl Ricinoleate. Int J Toxicol. 2007;26 Suppl 3:31-77. doi: 10.1080/10915810701663150. PMID: 18080873.

Abstract. The oil derived from the seed of the Ricinus communis plant and its primary constituent, Ricinoleic Acid, along with certain of its salts and esters function primarily as skin-conditioning agents, emulsion stabilizers, and surfactants in cosmetics, although other functions are described. Ricinus Communis (Castor) Seed Oil is the naming convention for castor oil used in cosmetics. It is produced by cold pressing the seeds and subsequent clarification of the oil by heat. Castor oil does not contain ricin because ricin does not partition into the oil. Castor oil and Glyceryl Ricinoleate absorb ultraviolet (UV) light, with a maximum absorbance at 270 nm. Castor oil and Hydrogenated Castor Oil reportedly were used in 769 and 202 cosmetic products, respectively, in 2002; fewer uses were reported for the other ingredients in this group. The highest reported use concentration (81%) for castor oil is associated with lipstick. Castor oil is classified by Food and Drug Administration (FDA) as generally recognized as safe and effective for use as a stimulant laxative. The Joint Food and Agriculture Organization (FAO)/World Health Organization (WHO) Expert Committee on Food Additives established an acceptable daily castor oil intake (for man) of 0 to 0.7 mg/kg body weight. Castor oil is hydrolyzed in the small intestine by pancreatic enzymes, leading to the release of glycerol and Ricinoleic Acid, although 3,6-epoxyoctanedioic acid, 3,6-epoxydecanedioic acid, and 3,6-epoxydodecanedioic acid also appear to be metabolites. Castor oil and Ricinoleic Acid can enhance the transdermal penetration of other chemicals. Although chemically similar to prostaglandin E(1), Ricinoleic Acid did not have the same physiological properties. These ingredients are not acute toxicants, and a National Toxicology Program (NTP) subchronic oral toxicity study using castor oil at concentrations up to 10% in the diet of rats was not toxic. Other subchronic studies of castor oil produced similar findings. Undiluted castor oil produced minimal ocular toxicity in one study, but none in another. Undiluted castor oil was severely irritating to rabbit skin in one study, only slightly irritating in another, mildly irritating to guinea pig and rat skin, but not irritating to miniature swine skin. Ricinoleic Acid was nonirritating in mice and in one rabbit study, but produced well-defined erythema at abraded and intact skin sites in another rabbit study. Zinc Ricinoleate was not a sensitizer in guinea pigs. Neither castor oil nor Sodium Ricinoleate was genotoxic in bacterial or mammalian test systems. Ricinoleic Acid produced no neoplasms or hyperplasia in one mouse study and was not a tumor promoter in another mouse study, but did produce epidermal hyperplasia. Castor oil extract had a strong suppressive effect on S(180) body tumors and ARS ascites cancer in male Kunming mice. No dose-related reproductive toxicity was found in mice fed up to 10% castor oil for 13 weeks. Female rats injected intramuscularly with castor oil on the first day after estrus had suppressed ovarian folliculogenesis and anti-implantation and abortive effects. Castor oil used as a vehicle control in rats receiving subcutaneous injections had no effect on spermatogenesis. A methanol extract of Ricinus communis var. minor seeds (ether-soluble fraction) produced anti-implantation, anticonceptive, and estrogenic activity in rats and mice. Clinically, castor oil has been used to stimulate labor. Castor oil is not a significant skin irritant, sensitizer, or photosensitizer in human clinical tests, but patients with occupational dermatoses may have a positive reaction to castor oil or Ricinoleic Acid. The instillation of a castor oil solution into the eyes of nine patients resulted in mild and transient discomfort and minor epithelial changes. In another study involving 100 patients, the instillation of castor oil produced corneal epithelial cell death and continuity breaks in the epithelium. Because castor oil contains Ricinoleic Acid as the primary fatty acid group, the Cosmetic Ingredient Review (CIR) Expert Panel considered the safety test data on the oil broadly applicable to this entire group of cosmetic ingredients. The available data demonstrate few toxic effects. Although animal studies indicate no significant irritant or sensitization potential, positive reactions to Ricinoleic Acid in selected populations with identified dermatoses did suggest that sensitization reactions may be higher in that population. Overall, however, the clinical experience suggests that sensitization reactions are seen infrequently. In the absence of inhalation toxicity data on these ingredients, the Panel determined that these ingredients can be used safely in aerosolized cosmetic products because the particle sizes produced are not respirable. Overall, the CIR Expert Panel concluded that these cosmetic ingredients are safe in the practices of use and concentrations as described in this safety assessment.