This package insert follows the Pharmaceuticals, Medical devices and Other Therapeutic Products Act of Japan.
In Vitro Diagnostics
Marketing Notification No. 13A2X00197218107**Revised: January 2020 (8th edition)*Revised: December 2017 (7th edition)

This package insert must be read carefully prior to use.
Valproic acid assay kit(Classification No.: 30404000)

competes with other antiepileptic drugs for binding toalbumin, the free valproic acid concentration is higher
when it is coadministered with other antiepileptic
drugs than when it is used alone. Similarly, valproic
acid competes with salicylic acid and free fatty acids
for binding to albumin. Various metabolites of valproic
acid are produced by β-oxidation, ω-oxidation, orconjugation. Some of these metabolites haveanticonvulsant activity, while others are known tocause adverse reactions.
It has been reported that the risk of valproic acidcausing adverse reactions is lower than with any otherstandard antiepileptic drug. General adverse reactions
to valproic acid include gastrointestinal symptoms
such as nausea and vomiting. As serious adverse
reactions, symptoms related to the central nervous
system have been reported, including tremor, cloudingof consciousness, and coma. These reactions are often
noted during coadministration of valproic acid withother antiepileptic drugs. The above-mentioned
adverse reactions are dependent on the blood level ofvalproic acid. While rare, adverse reactions such as
hepatic
failure,Reye’ssyndrome(acuteencephalopathy), pancreatitis, and thrombocytopenia
are known to occur independently of the blood level.
It is well known that the time to reach the maximum
blood concentration and the biological half-life of
valproic acid show inter-individual variations, because
the volume of distribution, metabolism, andelimination of this drug differ among patients. It has
also been reported that these parameters show
considerable variation depending on the dosage formof this drug. Metabolism of valproic acid is also
profoundly affected by coadministration with otherantiepileptic drugs. Therefore, monitoring the bloodlevel of valproic acid is important to determine theappropriate dosage.

Nanopia TDM Valproic Acid
General Precautions
1. This product is for in vitro diagnostic use, and mustnot be used for any other purposes.
2. Clinicians should make a comprehensive clinicaldecision based on assay results in conjunction withclinical symptoms and other examination results.
3. This product should be used only as directed in thispackage insert. Reliability of results cannot beguaranteed if there are any deviations from theinstructions in this package insert.
4. If the reagent accidentally comes in contact witheyes and/or mouth, rinse immediately with ample
water as first aid, and consult the doctor if required.
5. Carefully read the operating instructions for eachtype of automated analyzers prior to using thisproduct. Parameters for each type of analyzers areavailable, and can be requested from SEKISUIMEDICAL CO., LTD. if required.
6. Perform a quality control test prior to assay toensure accuracy.
Description (Kit Components)
Component: Ingredients
VPA Antibody Solution 1:
Anti-valproicacidmousemonoclonal antibody
VPA Latex Reagent 2:
Valproic acid-coated latex
Intended Use
Measurement of valproic acid in serum or plasma

Valproic acid (2-propylpentanoic acid) is anantiepileptic drug that was developed relativelyrecently. It is mainly used for the treatment of primaryseizures and secondary generalized seizures. Valproic
acid is effective for primary generalized seizures,
especially myoclonic seizures that tend to be inducedby photic or sonic stimulation. It is also known to beeffective for the treatment of non-convulsive
generalized seizures and affective seizures such as
partial seizures in children. Valproic acid iscoadministered with other antiepileptic drugs.
However, recent studies have shown that valproic acidis also effective as monotherapy.1),2)
At the therapeutic range, 90% or more of valproic acidin the bloodstream is bound to plasma proteins,
especially albumin. The free valproic acidconcentration is generally correlated with the total
concentration of the drug. It has also been reported thatthe concentration of valproic acid in the cerebrospinal
fluid is correlated with the total or free plasma valproic
acid concentration at the therapeutic range. However,free valproic acid increases at higher concentrations
due to saturation of binding. Because valproic acid

Assay Principle
1. Assay Principle
When a certain amount of anti-valproic acidantibody is added and reacted with a sample,
consumption of the antibody depends on its content
in the sample. When valproic acid-coated latex isadded, residual anti-valproic acid antibody reacts
with the latex and forms aggregates. Since theextent of aggregation depends on the valproic acidconcentration in the sample, the valproic acidconcentration can be determined by measuring
aggregation as the change of absorbance.
Sample (valproic acid) + Anti-valproic acidantibody
Antigen-antibody reaction
Unreacted anti-valproic acid antibody + Valproic
acid-coated latex
Aggregation by antigenantibody reaction
2. Features
1) Because a highly specific monoclonal
antibody is used, this product shows excellent
sensitivity and accuracy.

12) Liquid reagents, ready-to-use.
3) Applicable to various automated analyzers.

Dosage/Administration (Assay Procedure)
1. Preparation of reagents
Reagent (1): VPA Antibody Solution 1 is readyto use.
Reagent (2): VPA Latex Solution 2 is ready touse.
Before using this product, gently invert the VPA
Latex Reagent 2 bottle to mix it thoroughly, andcheck that there are no bubbles.
2. Assay Procedure
This product is compatible with various types ofautomated analyzer. An example of the assay
procedure is indicated below.

Procedural Precautions ＊＊1. Properties of Samples and Sampling Methods
1) Samples
Serum and plasma (heparin plasma, EDTA
plasma and citrated plasma) may be used.
2) Storage of samples
If the isolated serum or plasma sample cannot
be tested on the same day, specimens should be
stored as follows:
2–8C: for tests within 7 days≤ -20C: for tests within 4 weeks
Bring samples to room temperature (15–30C)
before use.
3) Caution must be exercised, because aseparating agent, etc. in the blood collection
tube may affect assay values.3)
4) Sampling should be performed after removing
insoluble matter from the sample.
2. Interfering substances
1) Assay results are not affected by free bilirubin(up to 20 mg/dL), conjugated bilirubin (up to 20mg/dL), hemoglobin (up to 500 mg/dL),ascorbic acid (up to 50 mg/dL), formazinturbidity (up to 2500 FTU), or rheumatoid
factors (up to 450 IU/mL).
2) Because mouse antibody is used in the assay,
artifactual elevation of results may occur if thesample contains human anti-mouse antibody. In
this case, perform re-measurement by anothermethod.
3) Cross-reactivity
The following table summarizes the crossreactivity with the valproic acid-like substancesand other drugs.
ConcenCrosstration
Compoundreactivity
tested(%)(µg/mL)
2-Phenyl-21000
0.5ethylmalonamide
2-Propylglutaric acid500
10.6
Carbamazepine
10000.5
Carbamazepine-10,111000
0.6
epoxideClonazepam
1000
0.5
Diazepam20000.3
Phenobarbital
2000
0Phenytoin
4001
Primidone
1000
0.2
Salicylic acid1000
0.6
3. Others
1) Always use TDM Calibrator for Nanopia forcalibration.
2) Precautions for assay range
If the concentration of a target substance in thesample exceeds the measurement range, dilutethe sample with a separately sold diluent(manufactured by SEKISUI MEDICAL CO.,LTD.), and perform re-measurement.

37C Reagent 37C
Reagent
Measurement
(2)
(1)
53sec
270(Absorbance I※)
50 μL
150 μL sec
37CMeasurement
107 (Absorbance II※)
secCalculation ofconcentration※Absorbance I and II: Absorbance at 600 nm
Sample +2 μL

Calibration material: TDM Calibrator for Nanopia(Manufacture's assigned value)
Assessment of Assay Results ＊＊1. Reference Standard Range
The therapeutic rage of valproic acid has beenreported to be 50-100 μg/mL. In general, theconcentration over 200 μg/mL is considered as thetoxic zone, but the symptoms of adverse reaction
may occur within the zone of therapeutic
concentrations.4) Therefore, interpretation of assay
results should also be based on the patient's
clinical findings and other examination results.
It is recommended that the blood concentration ofvalproic acid should be measured in a sufficientnumber of samples for statistical analysis and thatits therapeutic range should be determined by each
medical institution.
2. There may be reactions or interfering reactions with
non-target substances. If assay results appear to beunreliable, repeat the measurement (if necessary,after dilution) or try another analytical methods.
＊＊

Performance ＊1. Sensitivity
1) The change of absorbance of the standard
solution (0 μg/mL) per minute is 0.15–0.30.
2) The ratio between the change of absorbance perminute with the standard solution (0 µg/mL)
and that with another standard solution (12.5µg/mL) is 68–95%.
2. Accuracy: 80–120 % of the expected assay value
3. Within-run Reproducibility:
Coefficient of variation ≤ 10 %(Test methods used for 1.–3. are in-house methods.)
4. Measurement Range5): (On Hitachi 7170S
automated analyzer)
12–150 μg /mL
5. Correlation5)
1) Serum N=66 r=0.998 y=1.08x–0.29
Control method: Approved in vitro diagnostic(enzyme immunoassay)

22) Plasma N=101
r=0.994y=1.04x+2.77
Control method: Approved in vitro diagnostic(enzyme immunoassay)
6. Standard Material
Valproic Acid (U.S. Pharmacopoeia)

Packaging
NamePackage
VPA Antibody
1 × 30 mL
Nanopia TDM Solution 1
Valproic Acid VPA Latex
1 × 10 mL
Reagent 2
Constituent reagents are available in otherconfigurations. For further details please contact
SEKISUI MEDICAL CO., LTD.

Precautions for Use or Handling
1. Precautions for Handling (to Ensure Safety)
1) All samples used in the test should be handled asa material possibly infected with HIV, HBV,HCV, or other viruses. To prevent infection, use
disposable gloves and avoid mouth pipetting
during the test.
2) Sodium azide is added as an antiseptic agent in
the VPA Antibody Solution 1 and VPA Latex
Reagent 2. Therefore, if the reagent comes in
accidentally contact with eyes, mouth or skin,rinse immediately with ample water as first aid,
and consult the doctor if required.
2. Precautions for use
1) This product should be stored as directed,without freezing. Freezing can deteriorate thereagents, which can produce inaccurate results.
Therefore, avoid using the reagents which havebeen previously frozen.
2) Do not use expired reagents. Use of suchreagents cannot guarantee the reliability ofmeasurement values.
3) Do not replenish the reagents.
4) Do not mix materials from different kit lotnumbers.
5) Do not perform the assay under direct sunlight
3. Precautions for Disposal
1) Before disposal, used samples and theircontainers must be immersed in sodium
hypochlorite solution at a concentration ofgreater than 0.1% for longer than 1 hour or
autoclaved at 121ºC for 20 minutes.
2 ）To prevent infections from spilled samples orsolutions containing samples, wipe the spilledarea thoroughly with disinfectants such as
sodium hypochlorite solution at a concentrationof greater than 0.1%.
3) The reagents and treated samples should bediscarded as medical waste or industrial waste
according to the waste disposal regulations.
4) The reagents should be disposed of inaccordance with the Water Pollution Control act
or related regulations.
5) Sodium azide has been added as an antiseptic
agent in the VPA Antibody Solution 1 and VPA
Latex Reagent 2. It can react with lead or copper
pipes to produce the highly explosive metal azide.
Therefore, the reagent should be flushed withlarge amounts of water during disposal.
4. Other precautions
Do not use the containers for other purposes.

References ＊＊1) Wilder B. J., Rangel R. J. ： Review of valproate
monotherapyin the treatment of generalized
tonic−clonic seizures.Am. J. Med. 84（Suppl 1A）：
7−13, 1988.
2) Chadwick D. W. ： Valproate monotherapy in themanagement of generalized and partial seizures.
Epilepsia 28 （Supplement 2）：S12−S17, 1987.
3) Sawada T. et. al.: J Med Pharm Sci, 51(1), 131−141,2004.
4) The Japanese Society of Therapeutic Drug
Monitoring. [Guideline for therapeutic drug
monitoring (TDM) for antiepileptic drug 2018].
Tokyo: Kanehara Shuppan; 2018, pp. 14-15, pp.
57-64.
5) In house data, SEKISUI MEDICAL CO., LTD.
Contact
SEKISUI MEDICAL CO., LTD.
international@sekisui.com

Manufacturer ＊SEKISUI MEDICAL CO., LTD.
1-3, Nihonbashi 2-chome, Chuo-ku, Tokyo, Japan

Storage and Shelf Life
1. Storage temperature: 2–8C
2. Shelf life: 20 months from the date of manufacture(The expiration date is printed on the outerpackage.)3