Cyclopentolate (DL-Cyclopentolate) is an atropine-like muscarinic receptor antagonist (inhibitor) with a pKB value of 7.8 for ciliary muscle muscarinic receptors. Cyclopentolate is a extensively usedantimuscarinic agent in ophthalmology.

Physicochemical Properties

Molecular Formula	C17H25NO3
Molecular Weight	291.39
Exact Mass	291.183
CAS #	512-15-2
Related CAS #	Cyclopentolate hydrochloride;5870-29-1
PubChem CID	2905
Appearance	Typically exists as solid at room temperature
Density	1.136g/cm3
Boiling Point	409.7ºC at 760mmHg
Melting Point	134-136 139 °C (hydrochloride salt)
Flash Point	201.5ºC
Index of Refraction	1.555
LogP	2.18
Hydrogen Bond Donor Count	1
Hydrogen Bond Acceptor Count	4
Rotatable Bond Count	7
Heavy Atom Count	21
Complexity	331
Defined Atom Stereocenter Count	0
SMILES	CN(C)CCOC(=O)C(C1=CC=CC=C1)C2(CCCC2)O
InChi Key	SKYSRIRYMSLOIN-UHFFFAOYSA-N
InChi Code	InChI=1S/C17H25NO3/c1-18(2)12-13-21-16(19)15(14-8-4-3-5-9-14)17(20)10-6-7-11-17/h3-5,8-9,15,20H,6-7,10-13H2,1-2H3
Chemical Name	2-(dimethylamino)ethyl 2-(1-hydroxycyclopentyl)-2-phenylacetate
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

ln Vivo	Ninety percent of rats given cyclopentolate (20 mg/kg) survive[3].
ADME/Pharmacokinetics	Absorption, Distribution and Excretion Absorbed following ophthalmic administration.
Toxicity/Toxicokinetics	Effects During Pregnancy and Lactation ◉ Summary of Use during Lactation No information is available on the use of cyclopentolate during breastfeeding. Anticholinergic drugs might interfere with breastfeeding. A single dose of ophthalmic cyclopentolate is not likely to interfere with breastfeeding; however, during long-term use, observe the infant for signs of decreased lactation (e.g., insatiety, poor weight gain). To substantially diminish the amount of drug that reaches the breastmilk after using eye drops, place pressure over the tear duct by the corner of the eye for 1 minute or more, then remove the excess solution with an absorbent tissue. ◉ Effects in Breastfed Infants Relevant published information was not found as of the revision date. ◉ Effects on Lactation and Breastmilk Anticholinergics can inhibit lactation in animals, apparently by inhibiting growth hormone and oxytocin secretion. Anticholinergic drugs can also reduce serum prolactin in nonnursing women. The prolactin level in a mother with established lactation may not affect her ability to breastfeed.
References	[1]. Öner V, Bulut A, Öter K. The effect of topical anti-muscarinic agents on subfoveal choroidal thickness in healthy adults. Eye (Lond). 2016;30(7):925‐928. [2]. Ishikawa H, DeSantis L, Patil PN. Selectivity of muscarinic agonists including (+/-)-aceclidine and antimuscarinics on the human intraocular muscles. J Ocul Pharmacol Ther. 1998;14(4):363‐373. [3]. Öner V, Bulut A, Öter K. The effect of topical anti-muscarinic agents on subfoveal choroidal thickness in healthy adults. Eye (Lond). 2016;30(7):925‐928.
Additional Infomation	Cyclopentolate is a carboxylic ester resulting from the formal condensation of (1-hydroxycyclopentyl)(phenyl)acetic acid with N,N-dimethylethanolamine. A tertiary amine antimuscarinic with actions similar to atropine, it is used as its hydrochloride salt to produce mydriasis (excessive dilation of the pupil) and cycloplegia (paralysis of the ciliary muscle of the eye) for opthalmic diagnostic procedures. It acts more quickly than atropine and has a shorter duration of action. It has a role as a mydriatic agent, a parasympatholytic, a muscarinic antagonist and a diagnostic agent. It is a carboxylic ester, a tertiary amino compound and a tertiary alcohol. It is functionally related to a (1-hydroxycyclopentyl)phenylacetic acid and a N,N-dimethylethanolamine. A parasympatholytic anticholinergic used solely to obtain mydriasis or cycloplegia. A parasympatholytic anticholinergic used solely to obtain mydriasis or cycloplegia. See also: Cyclopentolate Hydrochloride (has salt form). Drug Indication Used mainly to produce mydriasis and cycloplegia for diagnostic purposes. Mechanism of Action By blocking muscarinic receptors, cyclopentolate produces dilatation of the pupil (mydriasis) and prevents the eye from accommodating for near vision (cycloplegia). Pharmacodynamics Cyclopentolate is an anti-muscarinic in the same class as atropine and scopolamine. Cyclopentolate blocks the receptors in the muscles of the eye (muscarinic receptors). These receptors are involved controlling the pupil size and the shape of the lens. Cyclopentolate thus induces relaxation of the sphincter of the iris and the ciliary muscles. When applied topically to the eyes, it causes a rapid, intense cycloplegic and mydriatic effect that is maximal in 15 to 60 minutes; recovery usually occurs within 24 hours. The cycloplegic and mydriatic effects are slower in onset and longer in duration in patients who have dark pigmented irises.

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	3.4318 mL	17.1591 mL	34.3183 mL
	5 mM	0.6864 mL	3.4318 mL	6.8637 mL
	10 mM	0.3432 mL	1.7159 mL	3.4318 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.