---
kind: "section"
citation: "10 C.F.R. § 35.63"
title: "10"
number: "35.63"
heading: "Determination of dosages of unsealed byproduct material for medical use."
url: "https://uscodex.org/cfr/10/35.63"
---

# §35.63. Determination of dosages of unsealed byproduct material for medical use.

- (a) A licensee shall determine and record the activity of each dosage before medical use.
- (b) For a unit dosage, this determination must be made by—
  - (1) Direct measurement of radioactivity; or
  - (2) **A decay correction, based on the activity or activity concentration determined by—**
    - (i) A manufacturer or preparer licensed under [§ 32.72](/cfr/10/32.72.md) of this chapter or equivalent Agreement State requirements; or
    - (ii) An NRC or Agreement State licensee for use in research in accordance with a Radioactive Drug Research Committee-approved protocol or an Investigational New Drug (IND) protocol accepted by FDA; or
    - (iii) A PET radioactive drug producer licensed under [§ 30.32(j)](/cfr/10/30.32.md?p=j) of this chapter or equivalent Agreement State requirements.
- (c) For other than unit dosages, this determination must be made by—
  - (1) Direct measurement of radioactivity;
  - (2) Combination of measurement of radioactivity and mathematical calculations; or
  - (3) Combination of volumetric measurements and mathematical calculations, based on the measurement made by:
    - (i) A manufacturer or preparer licensed under [§ 32.72](/cfr/10/32.72.md) of this chapter or equivalent Agreement State requirements; or
    - (ii) A PET radioactive drug producer licensed under [§ 30.32(j)](/cfr/10/30.32.md?p=j) of this chapter or equivalent Agreement State requirements.
- (d) Unless otherwise directed by the authorized user, a licensee may not use a dosage if the dosage does not fall within the prescribed dosage range or if the dosage differs from the prescribed dosage by more than 20 percent.
- (e) A licensee shall retain a record of the dosage determination required by this section in accordance with [§ 35.2063](/cfr/10/35.2063.md).

## Notes

### Amendments

[67 FR 20370, Apr. 24, 2002, as amended at 72 FR 55931, Oct. 1, 2007]

### Authority

Authority: Atomic Energy Act of 1954, secs. 81, 161, 181, 182, 183, 223, 234, 274 (42 U.S.C. 2111, 2201, 2231, 2232, 2233, 2273, 2282, 2021); Energy Reorganization Act of 1974, secs. 201, 206 (42 U.S.C. 5841, 5846); 44 U.S.C. 3504 note.

### Source

Source: 67 FR 20370, Apr. 24, 2002, unless otherwise noted.

### Amendments

[67 FR 20370, Apr. 24, 2002, as amended at 72 FR 55931, Oct. 1, 2007]