is used to treat symptoms of overactive bladder, such as frequent urination and
inability to control urination. This is due to oxybutynin is an anticholinergic
medication can reduce muscle spasms of the bladder and urinary tract.
of action of oxybutynin, it inhibits the action of acetylcholine
neurotransmitters on smooth muscle particularly the M1 and M2 receptors of the
bladder, detrusor activity.
dosage regimen of oxybutynin is one tablet 2 – 4 times per day. The plasma
half-life ranges from 2 – 3 hours. Therefore the more effective medication for
the treatment and convenient have been developed to reduce the frequency of
medication and potential of side effect, including to improve the
pharmacokinetics (constant concentration was maintained over 24 hours with once
daily dosage regimen), minimizing the fluctuations between peak and trough
Ditropan XL® is
an extended release tablets, based on the osmotic controlled-release oral
delivery system (OROS). To maintained over 24 hours of plasma concentration. The
current Ditropan XL® extended-release tablets are
available as 5(Pale yellow, round, tablet), 10(Pink, round, tablet) and 15 mg (Gray,
round, tablet) tablets for oral use.
System Components and Performance
DITROPAN XL® uses osmotic
pressure to deliver oxybutynin chloride at a controlled rate over approximately
24 hours. The system consists of an osmotically active bilayer core, which is
surrounded by semi-transparent membranes. Bilayer cores consist of layers of
excipients and push layers. There are osmotically active components with
precision laser drill holes.
Proper name : oxybutynin chloride
name : benzeneacetic acid,
?-cyclohexyl-?-hydroxy-, 4-(diethylamino)-2- butynyl ester hydrochloride, (±)-.
4-(Diethylamino)-2-butynyl (±)-?-phenylcyclohexaneglycolate hydrochloride.
Molecular formula : C22H31NO3 .HCl
mass : 393.9
Structural formula :
Solubility : readily soluble in water and
acids, but relatively insoluble inalkalis.
Alison M. Comer
and Karen L. Goa Adis International Limited, Auckland, New Zealand, Extended-Release
Oxybutynin show comparison of mean plasma concentrations of R-oxybutynin
following administration of extended-release oxybutynin 10 mg once daily or
immediate-release oxybutynin 5mg every 8 hours for 1 day in 23 healthy
A graph shows that
extended-release oxybutynin 10 mg once daily slowly release oxybutynin into the
bloodstream and show target concentration over approximately 24
hours. Concentration fluctuations in extended-release oxybutynin are smaller
than fluctuations in immediate-release oxybutynin 5 mg every 8 hours.
oxide (MW. 200,000)
oxide (MW. 7,500,000)
HPMC (MW. 11,200)
The main processes can be divided
into following flow chart.
1.Comer AM, Goa KL. Extended-Release
Oxybutynin. Drugs & Aging. 2000;16(2):149-55.
2. Goldenberg MM.
An extended-release formulation of oxybutynin chloride for the treatment of
overactive urinary bladder. Clinical Therapeutics.21(4):634-42.
3. Gleason DM,
Susset J, White C, Munoz DR, Sand PK. Evaluation of a new once-daily
formulation of oxybutynin for the treatment of urinary urge incontinence11This
study was funded by the Alza Corporation on behalf of Crescendo Pharmaceuticals
Corporation, Palo Alto, California. Urology. 1999;54(3):420-3.