Isobutylparaben (Isobutyl 4-hydroxybenzoate) is a constitutive androstane receptor (CAR) activator. Isobutylparaben displays a broad-spectrum antimicrobial activity and is extensively used in personal care products and cosmetics.

Physicochemical Properties

Molecular Formula	C11H14O3
Molecular Weight	194.23
Exact Mass	194.094
CAS #	4247-02-3
Related CAS #	Isobutylparaben-d4;1219805-33-0
PubChem CID	20240
Appearance	Typically exists as solid at room temperature
Density	1.1±0.1 g/cm3
Boiling Point	302.3±15.0 °C at 760 mmHg
Melting Point	76°C
Flash Point	125.4±13.2 °C
Vapour Pressure	0.0±0.7 mmHg at 25°C
Index of Refraction	1.524
LogP	3.28
Hydrogen Bond Donor Count	1
Hydrogen Bond Acceptor Count	3
Rotatable Bond Count	4
Heavy Atom Count	14
Complexity	181
Defined Atom Stereocenter Count	0
SMILES	O=C(OCC(C)C)C1=CC=C(O)C=C1
InChi Key	XPJVKCRENWUEJH-UHFFFAOYSA-N
InChi Code	InChI=1S/C11H14O3/c1-8(2)7-14-11(13)9-3-5-10(12)6-4-9/h3-6,8,12H,7H2,1-2H3
Chemical Name	2-methylpropyl 4-hydroxybenzoate
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

References	[1]. Chieri Fujino, et al. Comparative Study of the Effect of 17 Parabens on PXR-, CAR- And PPARα-mediated Transcriptional Activation. Food Chem Toxicol. 2019 Nov;133:110792. [2]. Fei Meng, et al. Isobutylparaben Negatively Affects Porcine Oocyte Maturation Through Increasing Oxidative Stress and Cytoskeletal Abnormalities. Environ Mol Mutagen. 2020 Apr;61(4):433-444.
Additional Infomation	Isobutylparaben is a 4-hydroxybenzoate ester.

Solubility Data

Solubility (In Vitro)

DMSO : 100 mg/mL (514.85 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.5 mg/mL (12.87 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 (12.87 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in 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 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. Solubility in Formulation 3: ≥ 2.5 mg/mL (12.87 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.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	5.1485 mL	25.7427 mL	51.4854 mL
	5 mM	1.0297 mL	5.1485 mL	10.2971 mL
	10 mM	0.5149 mL	2.5743 mL	5.1485 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.