NDC codes

FDA NDC Directory
Product NDC (as listed)70518-4364Labeler and product segments. Claims need a package NDC.
Product NDC at billing width70518-4364Add the package segment from the table below.
Package NDCs as listed with the FDA, and the 11-digit 5-4-2 form used on claims. The highlighted digit is the added leading zero.
Package NDC11-digit (billing)PackageCopy
70518-4364-07051843640090 TABLET in 1 BOTTLE, PLASTIC (70518-4364-0)Marketed from Jun 18, 2025
70518-4364-17051843640160 TABLET in 1 BOTTLE, PLASTIC (70518-4364-1)Marketed from Jan 29, 2026

How the 11-digit form is made: The package segment has 1 digit, so one leading zero is added to it (5-4-1 → 5-4-2). Formatting the NDC does not by itself make it billable — the product, package and quantity must match what was dispensed or administered, and payer rules apply. Conversion rules

Product information

Brand name (proprietary)
Chlorzoxazone
Generic name (nonproprietary)
chlorzoxazone
Active ingredients
Chlorzoxazone — 500 mg/1
Dosage form
Tablet
Route
Oral
Product type
Prescription drug
Marketing category
ANDA — Abbreviated New Drug Application (generic)Application ANDA 089853
Marketing start
Listing expires
Other FDA classes
Centrally-mediated Muscle Relaxation (Physiologic effect)
Identifiers
Product ID 70518-4364_4986f0f6-a218-6af3-e063-6394a90a34d3SPL ID 4986f0f6-a218-6af3-e063-6394a90a34d3SPL set ID 3f73a1d1-b3ee-4678-bc02-3258ec812127RxCUI 197502UNII H0DE420U8G
Pharmacologic class
Muscle Relaxant

Billing references

What Med-Code can say about coding this product, and where each statement comes from. Nothing here is inferred from the name alone.

HCPCS codeNo match

No HCPCS code in Med-Code's directory. Oral products like this are usually dispensed by a pharmacy and billed by NDC.

NDC on a medical claim

N470518436400 followed by a unit qualifier and the quantity

Package 70518-4364-00. Unit qualifiers: F2 (international unit), GR (gram), ME (milligram), ML (milliliter), UN (unit (each)). The qualifier and quantity depend on what was given. About the N4 qualifier

Product label

Current FDA label (SPL), effective .

Indications (excerpt from the label)

INDICATIONS AND USAGE Chlorzoxazone is indicated as an adjunct to rest, physical therapy, and other measures for the relief of discomfort associated with acute, painful musculoskeletal conditions. The mode of action of this drug has not been clearly identified, but may be related to its sedative properties. Chlorzoxazone does not directly relax tense skeletal muscles in man.

Excerpt only. Read the full label for complete information.

Full label on DailyMed (opens in a new tab)

Other NDCs under ANDA 089853

Products listed under the same FDA application: other strengths and forms, and repackagers who relabel the same product.

FDA NDC Directory listings under ANDA 089853
ProductStrengthForm · routeLabelerProduct NDC
ChlorzoxazoneChlorzoxazone 500 mg/1TabletOralBryant Ranch Prepack71335-2009
ChlorzoxazoneChlorzoxazone 375 mg/1TabletOralAurobindo Pharma Limited59651-305
ChlorzoxazoneChlorzoxazone 500 mg/1TabletOralAurobindo Pharma Limited59651-306
ChlorzoxazoneChlorzoxazone 750 mg/1TabletOralAurobindo Pharma Limited59651-307
ChlorzoxazoneChlorzoxazone 375 mg/1TabletOralAdvanced Rx of Tennessee, LLC80425-0525
ChlorzoxazoneChlorzoxazone 750 mg/1TabletOralAdvanced Rx of Tennessee, LLC80425-0526
ChlorzoxazoneChlorzoxazone 500 mg/1TabletOralAdvanced Rx Pharmacy of Tennessee, LLC80425-0315
ChlorzoxazoneChlorzoxazone 500 mg/1TabletOralProficient Rx LP71205-711

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