Zinc stearate or Zinc distearate. Zinc stearate could be utilized as pharmaceutical excipients such as lubricants for tablets and capsules. Pharmaceutical excipients or pharmaceutical auxiliaries refer to other chemical substances other than drug ingredients used in the pharmaceutical process. Pharmaceutical excipients generally refer to inactive ingredients in pharmaceutical preparations, which can improve the stability, solubility and processability of pharmaceutical preparations. Pharmaceutical excipients can also affect the absorption, distribution, metabolism, and elimination (ADME) processes of co-administered drugs.

Physicochemical Properties

Molecular Formula	C36H70O4ZN
Molecular Weight	632.32
Exact Mass	630.456
CAS #	557-05-1
PubChem CID	11178
Appearance	White powder free from gritiness Fine, soft, bulky powder
Density	1.095
Boiling Point	359.4ºC at 760 mmHg
Melting Point	128-130 °C (lit.)
Flash Point	180℃
LogP	6.33
Hydrogen Bond Donor Count	0
Hydrogen Bond Acceptor Count	4
Rotatable Bond Count	30
Heavy Atom Count	41
Complexity	196
Defined Atom Stereocenter Count	0
SMILES	[Zn+2].[O-]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])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H])=O.[O-]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])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H])=O
InChi Key	XOOUIPVCVHRTMJ-UHFFFAOYSA-L
InChi Code	InChI=1S/2C18H36O2.Zn/c2*1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18(19)20;/h2*2-17H2,1H3,(H,19,20);/q;;+2/p-2
Chemical Name	zinc;octadecanoate
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

ADME/Pharmacokinetics	Absorption, Distribution and Excretion In humans with no excessive intake of zinc, the body burden half-time of absorbed radio-labelled zinc has been observed to range from 162 to 500 days. After parenteral administration of 65Zn2+, half-times ranged from 100 to 500 days. /Zinc ions/ Within certain limits, mammals can maintain the total body zinc and the physiologically required levels of zinc in the various tissues constant, both at low and high dietary zinc intakes. The sites of regulation of zinc metabolism are: absorption of Zn2+ from the gastrointestinal tract, excretion of zinc in urine, exchange of zinc with erythrocytes, release of zinc from tissue, and secretion of zinc into the gastrointestinal tract. Regulation of gastrointestinal absorption and gastrointestinal secretion probably contributes the most to zinc homeostasis. /Zinc ions/ Metabolism / Metabolites Zinc is mostly bound to organic ligands rather than free in solution as a cation. Zinc is found in diffusible and non-diffusible forms in the blood and about 66% of the diffusible form of zinc in the plasma is freely exchangeable and loosely bound to albumin. A small amount of the non-diffusible form of zinc is tightly bound to 2-macroglobulin in the plasma and is not freely exchangeable with other zinc ligands. Zinc is incorporated into and dissociated from alpha2-macroglobulin only in the liver. /Zinc ions/ Zinc can enter the body through the lungs, skin, and gastrointestinal tract. Intestinal absorption of zinc is controlled by zinc carrier protein CRIP. Zinc also binds to metallothioneins, which help prevent absorption of excess zinc. Zinc is widely distributed and found in all tissues and tissues fluids, concentrating in the liver, gastrointestinal tract, kidney, skin, lung, brain, heart, and pancreas. In the bloodstream zinc is found bound to carbonic anhydrase in erythrocytes, as well as bound to albumin, _2-macroglobulin, and amino acids in the the plasma. Albumin and amino acid bound zinc can diffuse across tissue membranes. Zinc is excreted in the urine and faeces. (L49) Biological Half-Life For zinc, whole body: 162-500 days; [TDR, p. 1245] In humans with no excessive intake of zinc, the body burden half-time of absorbed radio-labelled zinc has been observed to range from 162 to 500 days. After parenteral administration of 65Zn2+, half-times ranged from 100 to 500 days. /Zinc ions/
Toxicity/Toxicokinetics	Toxicity Summary Anaemia results from the excessive absorption of zinc suppressing copper and iron absorption, most likely through competitive binding of intestinal mucosal cells. Unbalanced levels of copper and zinc binding to Cu,Zn-superoxide dismutase has been linked to amyotrophic lateral sclerosis (ALS). Stomach acid dissolves metallic zinc to give corrosive zinc chloride, which can cause damage to the stomach lining. Metal fume fever is thought to be an immune response to inhaled zinc. (L48, L49, A49) Toxicity Data LD50: >10000 mg/kg (Oral, Rat) (L546) LD50: 354 mg/kg (Intraperitoneal, Mouse) (L546) Non-Human Toxicity Values LD50 Rat ip 0.25 g/kg /SRP: 250mg/kg/ LD50 Rat oral >5000 mg/kg LC50 Rat Inhalation >200 mg/L (1 hr) LD50 Rabbit dermal >2000 mg/kg
References	[1]. Lower E S. Zinc stearate: its properties and uses. Pigment & Resin Technology, 1982, 11(6): 9-14. [2]. Pharmaceutical excipients - quality, regulatory and biopharmaceutical considerations. Eur J Pharm Sci. 2016 May 25;87:88-99.
Additional Infomation	Zinc stearate is a white, hydrophobic powder with a slight, characteristic odor. Mp: 130 °C. Density: 1.1 g cm-3. Insoluble in water, ethyl alcohol and diethyl ether. Soluble in acids. Non-toxic. In technical grades, the percentage of zinc may vary according to the intended use. Products with less than the theoretical amount of zinc are more acidic. Zinc stearate is a chemical compound of zinc. It is used mainly as a releasing agent and lubricant in the rubber and plastics industry. Zinc is a metallic element with the atomic number 30. It is found in nature most often as the mineral sphalerite. Though excess zinc in harmful, in smaller amounts it is an essential element for life, as it is a cofactor for over 300 enzymes and is found in just as many transcription factors. (L48, L49, L78) Therapeutic Uses Zinc stearate is a mild antiseptic and astringent, and it has been used as a local soothing application for inflammatory and irritating skin diseases. Zinc stearate is primarily used in pharmacuetical formulations as a lubricant in tablet and capsule manufacture at concentrations up to 1.5% w/w. In dental cement Drug Warnings ... Its use as dusting powder for infants is not recommended.

Solubility Data

Solubility (In Vitro)

May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples

Solubility (In Vivo)

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples. Injection Formulations (e.g. IP/IV/IM/SC) Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline) *Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution. Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline) Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil) Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals). Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)] *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. Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline) Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline) Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline) Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil) Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline) Oral Formulations Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium) Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals). Oral Formulation 3: Dissolved in PEG400 Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose Oral Formulation 6: Mixing with food powders Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	1.5815 mL	7.9074 mL	15.8148 mL
	5 mM	0.3163 mL	1.5815 mL	3.1630 mL
	10 mM	0.1581 mL	0.7907 mL	1.5815 mL

*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.