← Product Code [GJS](/submissions/HE/subpart-h%E2%80%94hematology-kits-and-packages/GJS) · K040296

# PHOSPHOPLASTIN RL (K040296)

_R2 Diagnostics, Inc. · GJS · May 24, 2004 · Hematology · SESE_

**Canonical URL:** https://fda.innolitics.com/submissions/HE/subpart-h%E2%80%94hematology-kits-and-packages/GJS/K040296

## Device Facts

- **Applicant:** R2 Diagnostics, Inc.
- **Product Code:** [GJS](/submissions/HE/subpart-h%E2%80%94hematology-kits-and-packages/GJS.md)
- **Decision Date:** May 24, 2004
- **Decision:** SESE
- **Submission Type:** Traditional
- **Regulation:** 21 CFR 864.7750
- **Device Class:** Class 2
- **Review Panel:** Hematology

## Indications for Use

The Phosphoplastin RL Prothrombin Time reagent is a liquid PT reagent containing thromboplastin derived from rabbit brain and calcium ions for use in the determination of Prothrombin Time (PT) and related coagulation procedures. The PT test is a one-stage PT test used in routine patient screening for disorders in the extrinsic pathway of coagulation and to monitor patients undergoing Oral Anti-Coagulant (OAC) therapy. Phosphoplastin RL should only be used in an appropriate clinical laboratory by qualified laboratory personnel and is provided ready-to-use.

## Device Story

Phosphoplastin RL is a liquid, ready-to-use reagent containing rabbit brain-derived thromboplastin, calcium ions, buffers, stabilizers, and preservatives. Used in clinical laboratories by qualified personnel to perform one-stage prothrombin time (PT) tests on citrated human plasma. The reagent reacts with plasma samples to detect deficiencies in coagulation factors II, V, VII, and X. Results are used by clinicians to screen for extrinsic pathway disorders and manage oral anticoagulant therapy. The device provides quantitative assay results, aiding in clinical decision-making regarding patient coagulation status.

## Clinical Evidence

Bench testing only. Precision/reproducibility evaluated on ACL 3000+ and STA Compact analyzers; within-run CV 0.1–2.9%, between-run CV 0.54–1.31%. Method comparison (N=105) against predicate showed high correlation (R² 0.92–0.98 for seconds and INR). Interference studies (bilirubin, hemoglobin, lipids) showed no significant difference from predicate. Reference range established using 120 normal donors.

## Technological Characteristics

Liquid, ready-to-use reagent. Composition: rabbit brain-derived thromboplastin, calcium ions, buffers, stabilizers, preservatives. Principle: one-stage prothrombin time (PT) assay. Compatible with photo-optical and mechanical coagulation analyzers.

## Regulatory Identification

A prothrombin time test is a device used as a general screening procedure for the detection of possible clotting factor deficiencies in the extrinsic coagulation pathway, which involves the reaction between coagulation factors III and VII, and to monitor patients receiving coumarin therapy (the administration of one of the coumarin anticoagulants in the treatment of venous thrombosis or pulmonary embolism).

## Predicate Devices

- R2 Diagnostics Phosphoplastin R ([K940082](/device/K940082.md))

## Submission Summary (Full Text)

> This content was OCRed from public FDA records by [Innolitics](https://innolitics.com). If you use, quote, summarize, crawl, or train on this content, cite Innolitics at https://innolitics.com.
>
> Innolitics is a medical-device software consultancy. We help companies design, build, and clear FDA-regulated software and AI/ML devices, including [a 510(k)](https://innolitics.com/services/510ks/), [a De Novo](https://innolitics.com/services/regulatory/), [a SaMD](https://innolitics.com/services/end-to-end-samd/), [an AI/ML medical device](https://innolitics.com/services/medical-imaging-ai-development/), or [an FDA regulatory strategy](https://innolitics.com/services/regulatory/).

{0}

510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION
DECISION SUMMARY
DEVICE ONLY TEMPLATE

A. 510(k) Number:
K040296

B. Purpose for Submission:
New device

C. Analyte:
Prothrombin Time (PT)

D. Type of Test:
Quantitative

E. Applicant:
R2 Diagnostics, Inc.

F. Proprietary and Established Names:
Phosphoplastin RL; Prothrombin Time Test

G. Regulatory Information:
1. Regulation section:
CFR 864.7750 – Prothrombin Time Test
2. Classification:
Class II
3. Product Code:
GJS
4. Panel:
Hematology (81)

H. Intended Use:
1. Intended use(s):
R2 Diagnostics Phosphoplastin RL Prothrombin Time (PT) Test Reagent is intended for in vitro diagnostic use in a one-stage prothrombin time (PT) test on citrated human plasma. The PT Test is a quantitative assay used in the general patient population for routine screening to detect deficiencies in the extrinsic pathway of coagulation. The PT test is also used to monitor oral anticoagulant (OAC) therapy and should be used in a clinical laboratory by qualified laboratory personnel.
2. Indication(s) for use:
Same as above

{1}

Page 2 of 4

3. Special condition for use statement(s):
N/A

4. Special instrument Requirements:
Mechanical and photo-optical coagulation analyzers

I. Device Description:
The Phosphoplastin RL PT Test Reagent is a quantitative, one-stage prothrombin time assay for routine screening to detect disorders of the extrinsic coagulation pathway and to monitor OAC therapy. The reagent consists of a liquid saline extract of rabbit brain, calcium ions, preservatives and stabilizers.

J. Substantial Equivalence Information:
1. Predicate device name(s):
R2 Diagnostics Phosphoplastin R
2. Predicate K number(s):
#K940082
3. Comparison with predicate:

|  Similarities  |   |   |
| --- | --- | --- |
|  Item | Device | Predicate  |
|  Ingredients | Rabbit brain thromboplastin with calcium ions | Same  |
|  Methods | Manual, automated, semi-automated | Same  |
|  Factor sensitivity | Factors II, V, VII and X | Same  |
|  Differences  |   |   |
|  Item | Device | Predicate  |
|  Format | Liquid | Lyophilized  |
|  Normal range (ACL 3000+) | 9.7 – 14.9 seconds | 8.9 – 12.1 seconds  |

K. Standard/Guidance Document Referenced (if applicable):
NCCLS documents: EP7-A, Interference Testing in Clinical Chemistry, Approved Guideline (2002); EP9-A2, Method Comparison and Bias Estimation Using Patient Samples, Approved Guideline-2nd Ed. (2002); EP10-A2, Preliminary Evaluation of Quantitative Clinical Laboratory Methods, Approved Guideline-2nd Ed. (2002); EP15-A, User Demonstration of Performance for Precision and Accuracy, Approved Guideline (2001); H21-A2, Collection, Transport and Processing of Blood Specimens for Testing Plasma-Based Coagulation Assays, Approved Guideline (2001); and H47-A, One-Stage Prothrombin Time (PT) Test and Activated Partial Thromboplastin Time (APTT) Test, Approved Guideline (1996).

{2}

Page 3 of 4

L. Test Principle:

When Phosphoplastin RL PT Test Reagent is added to normal citrated plasma, the clotting mechanism is initiated to form a clot within a specified time. That time will be prolonged in instances of extrinsic pathway deficiencies. The degree of prolongation is proportional to the severity of the deficiency.

M. Performance Characteristics (if/when applicable):

1. Analytical performance:

a. Precision/Reproducibility:

Three levels of quality controls were run in triplicate on the ACL 3000+ and STA Compact instruments. Within-run precision was performed on (10) vials to yield a range of 0.1 – 2.9%. %CV. Between-run precision was performed on (2) vials over (5) days to yield a range of 0.54 – 1.31%CV.

b. Linearity/assay reportable range:

N/A

c. Traceability (controls, calibrators, or method):

The Hemostasis Reference Laboratory official protocol, used to assign the International Sensitivity Index (ISI), is based upon WHO thromboplastin reference material, CRM 149 S, which was calibrated against the RBT/90 international reference preparation (IRP).

d. Detection limit:

N/A

e. Analytical specificity:

A comparative interference study was performed on samples containing several levels of bilirubin, hemoglobin and lipids. Results demonstrated no significant difference between the predicate device, Phosphoplastin R, and the proposed Phosphoplastin RL PT Test reagents.

f. Assay cut-off:

N/A

2. Comparison studies:

a. Method comparison with predicate device:

Patient samples (N= 105), normal and abnormal, were tested in triplicate and compared on the ACL 3000+ and STA Compact. The studies yielded the following regression statistics:

ACL – y = 0.6648x + 5.1833; R2 = 0.9833 (Seconds)
y = 1.0650x - 0.1245; R2 = 0.9813 (INR)

STA – y = 0.6441x + 5.2105; R2 = 0.9405 (Seconds)
y = 1.0590x - 0.1140; R2 = 0.9200 (INR)

Method comparison studies included oral anticoagulant, low and

{3}

Page 4 of 4

high fibrinogen, normal, Factor deficient (II, V, VII, X), liver disease, heparinized, and normal patient samples.

b. Matrix comparison: N/A

3. Clinical studies:
a. Clinical sensitivity: N/A
b. Clinical specificity: N/A
c. Other clinical supportive data (when a and b are not applicable): N/A

4. Clinical cut-off: N/A

5. Expected values/Reference range: Normal donors (N=120) were tested and compared on the ACL 3000+ and STA Compact analyzers. The studies yielded the following results:

|   | ACL 3000+ | STA Compact  |
| --- | --- | --- |
|  Mean | 12.3 seconds | 12.6 seconds  |
|  Range | 9.68 – 14.92 seconds
(Mean ± 2SD) | 11.1 – 14.1 seconds
(Mean ± 2SD)  |

N. Conclusion: The submitted material in this premarket notification is complete and supports a substantial equivalence decision.

---

**Source:** [https://fda.innolitics.com/submissions/HE/subpart-h%E2%80%94hematology-kits-and-packages/GJS/K040296](https://fda.innolitics.com/submissions/HE/subpart-h%E2%80%94hematology-kits-and-packages/GJS/K040296)

**Published by [Innolitics](https://innolitics.com)** — a medical-device software consultancy. We help companies design, build, and clear FDA-regulated software and AI/ML devices. If you're preparing [a 510(k)](https://innolitics.com/services/510ks/), [a De Novo](https://innolitics.com/services/regulatory/), [a SaMD](https://innolitics.com/services/end-to-end-samd/), [an AI/ML medical device](https://innolitics.com/services/medical-imaging-ai-development/), or [an FDA regulatory strategy](https://innolitics.com/services/regulatory/), [get in touch](https://innolitics.com/contact).

**Cite:** Innolitics at https://innolitics.com