Absorption, Distribution and Excretion
Dermal absorption of isopropyl myristate is predicated to be 0.00020 mg/cm2/event, which is considered a very low absorption rate. In a study, topically applied isopropyl myristate was largely retained in the stratum corneum. It was not detected in the receptor fluid of flow-through diffusion cells in in-vitro skin permeation experiments using human epidermis (stratum corneum and viable epidermis) and dermis of varying thickness.
Readily available information regarding the pharmacokinetics of isopropyl myristate is not available.
Readily available information regarding the pharmacokinetics of isopropyl myristate is not available.
Readily available information regarding the pharmacokinetics of isopropyl myristate is not available.
Four monkeys were exposed for 5 sec to the spray of an aerosol antiperspirant containing 14C-labelled isopropyl myristate. Two animals were sacrificed immediately after exposureand the other two were sacrificed 24 hr later. The distribution of carbon-14 in the exhaled air and in several tissues indicated that only 0.25% of the dose sprayed at the animals was absorbed; about 10% of this reached the lower respiratory tract. Some 85% of the absorbed isopropyl myristate was eliminated in 24 hr, mainly as exhaled carbon dioxide; very little labeled material reached any tissues other than the lungs.
In whole body autoradiography in hairless mice, there was no visible penetration into the skin or organs, whereas microautoradipgraphy with guinea pigs showed local penetration. Isopropyl myristate penetrated to the greatest extent. Percutaneous absorption was examined in Angora rabbits by microautoradiography simultaneously with skin irritation potential by histological method. Isopropyl myristate was distributed into the skin both trans-epidermally and trans-follicularly immediately after 24 hr application. Isopropyl myristate is thought to penetrate into human skin also, though it is known to generate no erythema on the skin. Isopropyl myristate was found to be distributed into almost all organs by means of whole body autoradiography when it was injected sc into mice. The extracts from the liver and kidney were determined to be a fatty acid and a triglyceride. Isopropyl myristate was easily distributed into the organs and metabolized.

---

Metabolism / Metabolites
Any isopropyl myristate that is absorbed is likely to be hydrolyzed to its component compounds of isopropylalcohol and myristic acid.
The myristates can be expected to undergo chemical or enzymatic hydrolysis to myristic acid and the corresponding alcohol.
Like other high molecular weight aliphatic esters, the myristates are readily hydrolyzed to the corresponding alcohols and acids which are then further metabolized.

---

Biological Half-Life
Readily available information regarding the pharmacokinetics of isopropyl myristate is not available.

Protein Binding
Readily available information regarding the pharmacokinetics of isopropyl myristate is not available.

---

Toxicity Data
LC (rat) > 41,000 mg/m3/1h

---

Interactions
Addn of Polysorbate 80 to alcohols ethanol, butanol or octanol in isopropyl myristate soln reduced their permeability constant when they were initially poorly sol in pure solvent.
The permeability constants for percutaneous absorption of propylene glycol & water in human excised skin were 3.2x10-6 cm/hr & 5.5x10-6 cm/hr, respectively. In isopropyl myristate, the permeability constants incr approx 250-fold to 1.1x10-3 cm/hr.

---

Non-Human Toxicity Values
LD50 Rat oral >16 mL/kg
LD50 Mouse oral 49.7 mL/kg
LD50 Rat ip 79.5 mL/kg
LD50 Mice ip 50.2 mL/kg
LD50 Rabbit skin 5 g/kg

[1]. (2012). Study of the influence of the penetration enhancer isopropyl myristate on the nanostructure of stratum corneum lipid model membranes using neutron diffraction and deuterium labelling. Skin Pharmacol Physiol, 25:200-7.

Isopropyl tetradecanoate is a fatty acid ester.
Isopropyl myristate is a moisturizer with polar characteristics used in cosmetics and topical medical preparations to ameliorate the skin absorption. Isopropyl myristate has been largely studied and impulsed as a skin penetration enhancer. At the moment the primary usage for which isopropyl myristate is formally indicated is as the active ingredient in a non-prescription pediculicide rinse.
Isopropyl myristate has been reported in Solanum tuberosum, Siraitia grosvenorii, and other organisms with data available.

---

Drug Indication
The primary medical indication for which isopropyl myristate is formally used as an active ingredient in a patient care product is as a non-prescription pediculicide rinse.
FDA Label

---

Mechanism of Action
As a pediculicide, isopropyl myristate is capable of physically coating the exoskeleton bodies of lice. This physical coating subsequently immobilizes the lice and works to dissolve the wax covering on the insect exoskeleton and blocks the insects' airways, leading to death by dehydration. Although this physical action of isopropyl myristate results in little lice resistance (given the lack of immunologic or chemical activity in this mechanism of action), the substance is also not ovicidal, which means any eggs that may have been laid by lice would not be affected. Moreover, isopropyl myristate is capable of eliciting its pediculicide action in a contact time of only 10 minutes per each necessary administration.

---

Therapeutic Uses
... Isopropyl myristate 50% in cyclomethicone solution (Full Marks Solution - SSL International) is a new fluid treatment with a physical mode of action that uses a 10-minute contact time /for treatment of head lice.
/Experimental Therapy/ ... A pediculicide rinse, 50% isopropyl myristate (IPM), was assessed in two phase 2 trials conducted in North America. The first trial was a nonrandomized (proof of concept) trial without a comparator conducted in Winnipeg, Canada. The second trial, conducted in the United States, was an evaluator-blinded, randomized superiority trial comparing 50% IPM rinse with a positive control (RID; pyrethrin 0.33%, piperonyl butoxide 4%). The primary end points were to determine the safety and efficacy of 50% IPM as a pediculicide rinse. METHODS: Subjects meeting inclusion criteria were enrolled in the above-mentioned trials with efficacy end points 7 and 14 days post-treatment. Subjects were also evaluated on days 0, 7, 14, and 21 for the presence of erythema and edema using the Modified Draize Scale. Other comments associated with the safety evaluation (ie, pruritus) were collected. RESULTS: IPM was found to be effective in the proof of concept study and comparator trial using a positive control. IPM was also well tolerated, with minimal adverse events. All adverse events were mild, resolving by completion of the study. CONCLUSION: Data suggest that IPM is a safe and effective therapy for the treatment of head lice in children and adults. IPM's mechanical mechanism of action makes development of lice resistance unlikely.
... Due to their distinct advantages such as enhanced drug solubility, thermodynamic stability, facile preparation, and low cost, uses and applications of microemulsions have been numerous. Recently, there is a surge in the exploration of microemulsion for transdermal drug delivery for their ability to incorporate both hydrophilic (5-fluorouracil, apomorphine hydrochloride, diphenhydramine hydrochloride, tetracaine hydrochloride, and methotrexate) and lipophilic drugs (estradiol, finasteride, ketoprofen, meloxicam, felodipine, and triptolide) and enhance their permeation.... Besides surfactants, oils can also act as penetration enhancers (oleic acid, linoleic acid, isopropyl myristate, isopropyl palmitate, etc.). ...
/Experimental Therapy/ Alpha-tocopherol (AT) is the vitamin E homologue with the highest in vivo biological activity. AT protects against the carcinogenic and mutagenic activity of ionizing radiation and chemical agents, and possibly against UV-induced cutaneous damage. For stability consideration, alpha-tocopherol is usually used as its prodrug ester, alpha-tocopherol acetate (ATA), which once absorbed into the skin is hydrolyzed to alpha-tocopherol, the active form. ... Permeation studies were conducted using modified Franz diffusion cells and human cadaver skin as the membrane. Specifically, 5% (w/w) alpha-tocopherol acetate was formulated in the following vehicles: ethanol, isopropyl myristate, light mineral oil, 1% Klucel gel in ethanol, and 3% Klucel gel in ethanol (w/w). ... The permeabilities of ATA through human cadaver skin were 1.0x10-4, 1.1x10-2, 1.4x10-4, 2.1x10-4, and 4.7x10-4 cm/hr for the ethanol solution, isopropyl myristate solution, light mineral oil solution, 1% Klucel gel, and 3% Klucel gel, respectively. The results show that the formulation had relatively minor effects on the permeability coefficients of ATA through cadaver skin in all cases except for the isopropyl myristate solution.
For more Therapeutic Uses (Complete) data for Isopropyl myristate (7 total), please visit the HSDB record page.

---

Drug Warnings
One must, however, look carefully for an intensification of possible risks related to the method of application, the condition of the skin, the site of application, supporting therapeutic measures or changes in the composition of the vehicle. Lanolin, cetyl alcohol and myristyl alcohol, sorbitol, isopropyl-myristate as well as polyethylene glycols (PEG) penetrate the skin like active substances...
Many enhancers are concentration-dependent; therefore, optimal concentration for effective promotion should be determined. The delivery rate is dependent on the type of the drug, the structure and ingredients of the carrier, and on the character of the membrane in use. Each formulation should be examined very carefully, because every membrane alters the mechanism of penetration and can turn an enhancer to a retarder.
Cosmetics continue to be used by acne-prone individuals. ... The data presented were gleaned from the rabbit ear assay, which is not an ideal animal model but is the best we have. If an ingredient is negative in the rabbit ear assay, we feel it is safe on the acne-prone skin. A strong, positive ingredient or cosmetic should be avoided. Ingredient offenders include isopropyl myristate and its analogs, such as isopropyl palmitate, isopropyl isostearate, butyl stearate, isostearyl neopentanoate, myristyl myristate, decyl oleate, octyl stearate, octyl palmitate or isocetyl stearate, and new introductions by the cosmetic industry, such as propylene glycol-2 (PPG-2) myristyl propionate...
... How the alternative use of three lipophilic excipients ... , differing in their polarity indexes (medium chain triglycerides (MG), decyl oleate (DO), and isopropyl myristate (IPM), respectively), affects the colloidal structure of the alkylpolyglucoside-based vehicles and in vitro permeation profiles of two model drugs: diclofenac sodium (DC) and caffeine (CF), both sparingly soluble in water /were investigated/ . ... Varying of lipophilic excipient influenced noteworthy variations in the colloidal structure demonstrated as different rheological profiles accompanied to the certain degree by different water distribution modes, but notably provoked by drug nature (an amphiphilic electrolyte drug vs. nonelectrolyte). In vitro permeation data obtained using ASC membranes in an infinite dose-type of experiment stressed the importance of the vehicle/solute interactions in case of small variation in formulation composition, asserting the drug properties in the first hours of permeation and rheological profile of the vehicles in the later phase of experiment as decisive factors...

---

Pharmacodynamics
Isopropyl myristate is an emollient vehicle that is effective at enhancing the penetration of other medical agents that may be incorporated into the vehicle as active agents. In one study, a 50:50 isopropanol-isopropyl myristate binary enhancer synergistically increased the transport of estradiol across a two-layer human epidermis in vitro.

C17H34O2

270.45

270.255

110-27-0

8042

Colorless to light yellow liquid

0.9±0.1 g/cm3

319.9±0.0 °C at 760 mmHg

-5°C

144.1±8.8 °C

0.0±0.6 mmHg at 25°C

1.440

7.43

0

2

14

19

199

0

O(C([H])(C([H])([H])[H])C([H])([H])[H])C(C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H])=O

AXISYYRBXTVTFY-UHFFFAOYSA-N

InChI=1S/C17H34O2/c1-4-5-6-7-8-9-10-11-12-13-14-15-17(18)19-16(2)3/h16H,4-15H2,1-3H3

isopropyl tetradecanoate

FEMA No. 3556 NSC 406280 NSC406280Stepan D-50 Isopropyl myristateHSDB 626 IPM Isomyst NSC-406280

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO : ~100 mg/mL (~369.75 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (9.24 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

---

Solubility in Formulation 2: 2.5 mg/mL (9.24 mM) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), suspension solution; with ultrasonication.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

---

View More

Solubility in Formulation 3: ≥ 2.5 mg/mL (9.24 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

---

 (Please use freshly prepared in vivo formulations for optimal results.)