Oxybutynin Chloride

Inquiry

Cat Number

API0231584

CAS Number

1508-65-2

If you have any other questions, please contact our experts.

Product Detail Description Scientific Support Customer Q&A

CAS Number

1508-65-2

EINECS

216-139-7

Storage

Store at room temperature

Synonyms

Tropax; Ditropan Xl; MJ 4309-1; L9F3D9RENQ; NSC-759108; DTXSID3045356

Molecular Formula

C22H32ClNO3

Molecular Weight

393.9

Smiles

CCN(CC)CC#CCOC(=O)C(C1CCCCC1)(C2=CC=CC=C2)O.Cl

Appearance

White crystalline solid

Melting Point

124-129℃

Boiling Point

494.4℃ at 760 mmHg

General Description

Oxybutynin chloride is an antispasmodic, anticholinergic agent widely prescribed for overactive bladder syndrome. The drug exhibits a direct muscle relaxant effect on the detrusor in addition to its anticholinergic properties, distinguishing it from pure muscarinic antagonists.

Mechanism of Action

Oxybutynin works by competitively antagonizing muscarinic acetylcholine receptors, predominantly M2 and M3 subtypes, located on the detrusor smooth muscle. This blockade reduces involuntary bladder contractions and increases vesical capacity. The compound also exerts a direct papaverine-like spasmolytic action on smooth muscle independent of cholinergic pathways, further contributing to urinary urgency relief.

Application

Approved for the treatment of overactive bladder with symptoms of urge incontinence, urgency, and frequency, oxybutynin is also used for neurogenic detrusor overactivity in children. The transdermal formulation offers a lower incidence of anticholinergic side effects such as dry mouth and constipation compared to oral versions.

In a randomized, placebo‑controlled, double‑blind crossover trial (20 patients), a single bedtime dose of the norepinephrine reuptake inhibitor atomoxetine (80 mg) plus the antimuscarinic oxybutynin (5 mg) reduced the apnea‑hypopnea index (AHI) by 63%, from 28.5 to 7.5 events/hour (P<0.001). Fifteen patients with moderate‑to‑severe OSA on placebo (AHI >10) showed a 74% reduction, all achieving ≥50% improvement. Genioglossus muscle responsiveness increased threefold. Neither drug alone was effective. This drug combination holds promise as an oral pharmacotherapy for OSA.

Fig. 1 Consolidated Standards of Reporting Trials diagram of the clinical trial. (Taranto-Montemurro L, et al., 2019)

References

Taranto-Montemurro L, et al. The Combination of Atomoxetine and Oxybutynin Greatly Reduces Obstructive Sleep Apnea Severity. A Randomized, Placebo-controlled, Double-Blind Crossover Trial. Am J Respir Crit Care Med. 2019;199(10):1267-1276.

Does Oxybutynin Chloride require protection from light during long-term storage?

Yes, it is moderately photosensitive. Prolonged UV exposure can cause discoloration and degradation of the tertiary amine structure. Store in light-resistant containers.

What is the recommended storage temperature for Oxybutynin Chloride?

Store at controlled room temperature (15-25°C). Avoid excessive heat above 30°C, as it may soften the material and accelerate hydrolysis of the ester group.

Is Oxybutynin Chloride hygroscopic, and how is this managed?

It is slightly hygroscopic. Under high humidity (>70% RH), it may absorb moisture and clump. Storage in tightly sealed containers with desiccant is recommended.

How is the impurity phenylcyclohexylglycolic acid monitored during stability?

This primary hydrolysis product is quantified using a stability-indicating HPLC method, ensuring it remains below USP/EP limits throughout shelf life.