Transcript The USP Conference on Biologicals and Biotechnology

Oxytocin: Storage, Labeling and
Monograph Issues
Larry Callahan, Ph.D.
USP, Rockville, Maryland
U. S. Pharmacopeia/USP DQI

USP was founded in 1820 by the medical
community to standardize formulations

Leading non-government pharmacopeia
worldwide
USP Drug Quality and Information Program
— current cooperative agreement with U.S.
Agency for International Development (USAID)
that provides technical assistance in more than
20 countries. Its set objectives:

 To improve availability and appropriate use of
good quality pharmaceutical products
 To increase availability and use of unbiased
health information
USP Monograph Revision Process

Monographs are voluntary
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Monograph (revisions) submitted or suggested by
sponsor

Sponsor can be anyone, but is usually a manufacturer

Monograph drafted by liaison

Publication in PF

Comments received from public (comment period
usually about 5 months)

Monograph revised based on comment or forwarded
to Expert Committee/Board of Trustees for approval

Monograph published in USP-NF

Monograph becomes Official
USP–NF Today
Effect of USP Monograph

USP standards are enforceable by the U.S. FDA
and other governments

USP standards are enforceable throughout the
lifetime of the product or dosage form
“From production to consumption”

Not necessary to perform every USP test on
every batch or vial but must pass all USP tests if
tested

Monographs are tied to products, not
manufacturers; every manufacturer must meet
same monograph requirements

USP, BP, and JP have monographs on dosage
forms; EP has no product monographs
Oxytocin Injection Monograph History
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Oxytocin activity discovered by Dale 1909.
Oxytocin is first reported synthesized by Vincent du
Vigneaud in 1953. (Won Noble Prize in 1955)
Monograph first appeared in USP XV (1955) Animal
derived. 10 USP Units per mL. Packaging and
Storage (P&S)–Type I glass (no temperature req.)
USP XVI (1960) Allows for synthetic product. P&SAvoid excessive temperature; pH 2.5-3.6
USP XVII (1965) P&S-Refrigerator, Do not freeze;
Expiration date 3 years from assay date. pH 2.5-4.5
USP XIX (1975) P&S–Do not freeze. No expiration
date requirement.
USPXX (1980) 85-120% of label.
Oxytocin Injection Monograph History-2
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USP 23 1st Supp. (1995) 90-110% of label.
HPLC assay introduced. pH 3.0-5.0 (Oxytocin
monograph becomes official. Greater than 400
USP units per mL. P&S–refrigerator).
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USP 28 (2005) P&S–Store between 2° and 8°C.
Do not freeze removed from monograph.
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Reason for most recent monograph change —
Instability reported at 21°C and 30°C from one
manufacturer. At 30°C, 10-12% degradation
over 12 months. At 21°C, 3-5% degradation
over 24 months. At 5°C, product stable for 60
months. No information on pH or formulation.
Current Monographs in Pharmacopeias
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USP 29 Potency 90-110% of label; P&S–28°C; pH 3.0-5.0
EP 5.4 (No Product Monographs) Storage
Bulk Solution 2-8°C; pH 3.0-5.0
JP (2001) 85-120% of label. Bioassay
(Chicken). P&S–In a cold place (<= 15C;
avoid freezing.)
BP 90-110% of label. pH 3.5 to 4.5; no
current temperature criteria (Had
temperature control in 1995 of 2-15°C)
Current U.S. Manufacturer Storage
Conditions, Typical Expiration Dates
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American Pharmaceutical Partners
Controlled Room Temperature (From MSDS).
Expiration labeling 9 months (verbally
reported).
Parkedale (King) 2-8°C Allows short
excursions 30 days at 15-25°C. Expiration
date 2-3 years from preparation
(Martindale). Acetate buffered?
Novartis (New Zealand) 2-8°C Allows 30°C
for 3 months.
Oxytocin Chemistry and Stability
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Chemical Structure
MW 1007.2
Degradation Pathways
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Time scale for degradation at ambient temperatures – weeks,
not hours
Disulfides (reactions)
 Reduction
 Oxidation
 Disulfide exchange (scrambling)
Temperature and pH would have some effect but mostly effected by
added substances or initial material (free thiols, oxidizers or
reductants).
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Amides (Asparagine (ASN), Glutamine (GLN), C-terminal (CNH2), Peptide backbone)
 Deamidation (GLN and ASN)
• Half-life of ASN in proteins/peptides at 37.0, pH 7.4 (0.5 days-500
days)
• Half-life of GLN proteins/peptides at 37.0. pH 7.4 (600 days-2000 days)
From Robinson, N. E. and Robinson, A. B. (2004)
Molecular Clocks: Deamidation of Asparaginyl and Glutaminyl Residues in
Peptides and Proteins.
http://book.deamidation.org/MolecularClocks.pdf
Degradation Pathways-2
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Deamidation Pathways
 Imide (ring) formation, can be very fast
dependent on nearest neighbor, conformation
predominantly, some temperature and pH
effects.
 Hydrolysis much slower, dependence on
sequence, temperature and pH effects
predominate. Peptide backbone also effected.
 Hydrolysis can be both acid and base
catalyzed.
 Oxytocin can degrade by both imide
formation and hydrolysis
pH and Hydrolysis of Peptides
Hydrolysis of small peptide from polymeric support at 25°C.
From Kahne and Still, J.Am.Chem.Soc. 110:7529-7534 (1988)
Possible Changes in Storage Conditions
for Product Monograph
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Potential Storage Temperatures
 No required temperature conditions
 Controlled room temperature (monitor
temperature allow excursions)
 Controlled cold temperature (monitor
temperature allow excursions)
 Allow dual storage conditions but
expiration date must be based on a
single storage condition
Storage Temperature Definitions
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Cold — Any temperature not exceeding 8°
(46°F). A refrigerator is a cold place in which
the temperature is maintained thermostatically
between 2° and 8° (36° and 46°F).
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Cool — Any temperature between 8° and 15°C
(46° and 59°F). An article for which storage in
a cool place is directed may, alternatively, be
stored and distributed in a refrigerator, unless
otherwise specified by the individual
monograph.
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Room Temperature — The temperature
prevailing in a working area.
Storage Temperature Definitions-2
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Controlled Room Temperature — A temperature
maintained thermostatically that encompasses the
usual and customary working environment of 20° to
25°C (68° to 77°F); that results in a mean kinetic
temperature calculated to be not more than 25°C;
and that allows for excursions between 15° and 30°
(59° and 86°F) that are experienced in pharmacies,
hospitals, and warehouses. Provided the mean
kinetic temperature remains in the allowed range,
transient spikes up to 40°C are permitted as long as
they do not exceed 24 hours. Spikes above 40°C
may be permitted if the manufacturer so instructs.
Articles may be labeled for storage at “controlled
room temperature” or at “up to 25°,” or at other
wording based on the same mean kinetic
temperature. The mean kinetic temperature is a
calculated value that may be used as an isothermal
storage temperature that simulates the nonisothermal effects of storage temperature variations.
Storage Temperature Definitions-3
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Controlled Cold Temperature — This is defined
as the temperature maintained thermostatically
between 2° and 8°C (36° and 46° F) that allows
for excursions in temperatures between 0° and
15°C (32° and 59°F) that may be experienced
during storage, shipping, and distribution such
that the allowable calculated MKT is not more
than 8°C (46° F). Transient spikes up to 25°C
(77°F) are permitted provided that such spikes
do not exceed 24 hours, unless supported by
data or the manufacturer instructs otherwise.
Consequences of Higher Storage
Temperature
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Reduced Shelf-Life Due to an Increase in
Hydrolysis Rate
 More degradants
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Greater Chance of “Catastrophic” Failure?
 Product no longer in solution or completely
degraded, precipitation, aggregation,
adsorption.
 Catastrophic failure (precipitation) observed
in dilute solution in lactated ringer solutions
after 35 days at 30°C. Product seemed fine at
28 days. Cause not specified. Ringer contains
calcium. Not seen in other solutions. See
Trissel et al. Int. J. Pharm. Comp. 10:156158 (2006).
 Microbial growth more likely
How to Increase Shelf-Life
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Find optimum pH; tighter control on pH.
(USP Nasal Solution 3.7-4.3; no storage
temp specified)
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Lyophillization (freeze-dried) long shelf-life
~20 years (Current International RS)
 More expensive, very little material ~ 20 mg
 Reconstitution could be problematic
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Change specification in the monograph.
Allow 90-125% of label amount. This would
allow “overloading” and a longer shelf-life.
 The biological half-life of Oxytocin is five
minutes. This should allow slightly higher
dosing without adverse consequences.
Other Possible Changes in Oxytocin
Monographs
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Oxytocin
 Eliminate animal test (rat uterus contraction).
 Replace with LC-MS to allow identification and
quantification of impurities and related
compounds.
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Oxytocin Injection
 Add a related compounds test to monitor the
extent of degradation.
Information Needed for Further
Monograph Development
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Rate of Failure (Bad Vials; Catastrophic
failure)
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Identity of the Degradants
 Bioactivity of the degradants
 Oxytocin Agonist or Antagonist
 Substrate or inhibitor of Oxytocinase (a
plasma protease produced during pregnancy
that appears to target and inactivate
oxytocin. In the absence of oxytocinase, the
elimination half-life is 3-5 minutes
significantly shorter in its presence.
Larry Callahan, Ph.D.
Scientist, Standards Development
United States Pharmacopeia
12601 Twinbrook Parkway
Rockville, MD 20852
www.usp.org
[email protected]