Isosorbide Dicaprylate is a diester derived from isosorbide and caprylic acid, recognized for its emollient and moisturizing properties. Its molecular structure and physicochemical properties make it a versatile ingredient in cosmetic formulations, providing enhanced texture, smooth application, and non-greasy hydration. Its excellent skin tolerance and biodegradability position it as an eco-friendly alternative in premium skincare and haircare applications.

Chemical Composition and Structure
Isosorbide Dicaprylate is a diester compound synthesized by esterifying isosorbide, a bicyclic glucose derivative, with two molecules of caprylic acid (C8 fatty acid). The dual ester bonds in the molecule confer both hydrophobic and hydrophilic properties, enhancing its ability to act as an emollient and facilitating the dispersion of active ingredients in formulations.

Physicochemical Properties

• Appearance: Clear, colorless, slightly viscous liquid.
• Solubility: Soluble in oils, insoluble in water.
• Odor: Neutral.
• Stability: High thermal and oxidative stability, making it suitable for a wide range of cosmetic formulations.

Synthesis and Production
The synthesis of Isosorbide Dicaprylate involves an esterification reaction between isosorbide and caprylic acid. This process is typically catalyzed to ensure high efficiency and purity. The resulting product is subjected to refining steps to remove impurities and achieve a cosmetically acceptable grade.

Applications

• Medical: Utilized in dermatological formulations for its ability to enhance the bioavailability of active ingredients and provide hydration.
• Cosmetics:
  • Skincare: Incorporated in moisturizers, serums, and lotions for its lightweight hydration and smoothing properties.
  • Makeup: Enhances spreadability and imparts a silky texture in foundations and lip products.
  • Haircare: Used in conditioners and hair oils to improve manageability and impart softness.

INCI Functions

Skin conditioning agent. It is the mainstay of topical skin treatment as it has the function of restoring, increasing or improving skin tolerance to external factors, including melanocyte tolerance. The most important function of the conditioning agent is to prevent skin dehydration, but the subject is rather complex and involves emollients and humectants that can be added in the formulation.

Environmental and Safety Profile
Isosorbide Dicaprylate is biodegradable and exhibits a favorable safety profile, with low potential for skin irritation or sensitization. Its production from sustainable sources, such as plant-derived caprylic acid, minimizes its environmental impact. 

Molecular Formula  C₂₂H₃₈O₆

Molecular Weight  398.5 g/mol

CAS     64896-70-4

UNII    0IK29C4889

EC Number  807-840-4

DTXSID60215219

Nikkaji    J3.148.438C

Synonyms:

Synovea DOI

Nikkol sorester 208

References__________________________________________________________________________

Swindell WR, Bojanowski K, Chaudhuri RK. Isosorbide Fatty Acid Diesters Have Synergistic Anti-Inflammatory Effects in Cytokine-Induced Tissue Culture Models of Atopic Dermatitis. Int J Mol Sci. 2022 Nov 18;23(22):14307. doi: 10.3390/ijms232214307. 

Abstract. Atopic dermatitis (AD) is a chronic disease in which epidermal barrier disruption triggers Th2-mediated eruption of eczematous lesions. Topical emollients are a cornerstone of chronic management. This study evaluated efficacy of two plant-derived oil derivatives, isosorbide di-(linoleate/oleate) (IDL) and isosorbide dicaprylate (IDC), using AD-like tissue culture models. Treatment of reconstituted human epidermis with cytokine cocktail (IL-4 + IL-13 + TNF-α + IL-31) compromised the epidermal barrier, but this was prevented by co-treatment with IDL and IDC. Cytokine stimulation also dysregulated expression of keratinocyte (KC) differentiation genes whereas treatment with IDC or IDL + IDC up-regulated genes associated with early (but not late) KC differentiation. Although neither IDL nor IDC inhibited Th2 cytokine responses, both compounds repressed TNF-α-induced genes and IDL + IDC led to synergistic down-regulation of inflammatory (IL1B, ITGA5) and neurogenic pruritus (TRPA1) mediators. Treatment of cytokine-stimulated skin explants with IDC decreased lactate dehydrogenase (LDH) secretion by more than 50% (more than observed with cyclosporine) and in vitro LDH activity was inhibited by IDL and IDC. These results demonstrate anti-inflammatory mechanisms of isosorbide fatty acid diesters in AD-like skin models. Our findings highlight the multifunctional potential of plant oil derivatives as topical ingredients and support studies of IDL and IDC as therapeutic candidates.

Nadora D, Burney W, Chaudhuri RK, Galati A, Min M, Fong S, Lo K, Chambers CJ, Sivamani RK. Prospective Randomized Double-Blind Vehicle-Controlled Study of Topical Coconut and Sunflower Seed Oil-Derived Isosorbide Diesters on Atopic Dermatitis. Dermatitis. 2024 Jan-Feb;35(S1):S62-S69. doi: 10.1089/derm.2023.0329. 

Abstract. Background: Preliminary studies support the use of topical coconut and sunflower seed oil for atopic dermatitis (AD). However, standardized topical formulations of fatty acids from these sources have not been studied. Objective: This study investigates whether coconut oil- and sunflower seed oil-derived isosorbide diesters can be used in conjunction with colloidal oatmeal to improve itch, AD severity, and the need for topical steroids in adults. Methods: This was a single-center, 4-week, randomized, double-blind, and vehicle-controlled study conducted between 2021 and 2022. Thirty-two male and female adults with mild-to-moderate AD were enrolled and completed the study. Participants were randomized to receive either 0.1% colloidal oatmeal (vehicle) or isosorbide diesters (IDEAS, 4% isosorbide dicaprylate and 4% isosorbide disunflowerseedate) along with 0.1% colloidal oatmeal. The main outcomes of the study were changes in the visual analogue rating of itch and 75% improvement in the Eczema Area and Severity Index score (EASI 75) at 4 weeks. Other measures included the use of topical steroids and the relative abundance of skin Staphylococcus aureus. Results: Participants in the IDEAS group had a 65.6% improvement in itch compared with 43.8% in the vehicle group (P = 0.013). In total, 56.5% and 25% of the those in the IDEAS and vehicle groups, respectively, achieved EASI 75 at 4 weeks (P = 0.07). There was no difference in skin hydration or transepidermal water loss. The relative abundance of S. aureus was decreased in the IDEAS group at week 4 compared with no change in the vehicle group (P = 0.044). Topical corticosteroid use increased in the vehicle group compared with a decrease in the IDEAS group at week 1 (292.5% vs 24.8%; P value = 0.039) and week 2 (220% vs 46%; P value = 0.08). Conclusions: Topical application of emollients containing coconut oil- and sunflower seed oil-derived fatty esters may improve itch, reduce topical steroid use, and reduce the relative abundance of S. aureus in mild-to-moderate AD. CTR number: NCT04831892.

Chaudhuri RK, Bojanowski K. Improvement of hydration and epidermal barrier function in human skin by a novel compound isosorbide dicaprylate. Int J Cosmet Sci. 2017 Oct;39(5):518-526. doi: 10.1111/ics.12405.