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United States • Title 21 CFR • Part 331

Part 331PART 331—ANTACID PRODUCTS FOR OVER-THE-COUNTER (OTC) HUMAN USE

This part establishes the conditions under which over-the-counter (OTC) antacid products are generally recognized as safe and effective (GRASE) and not misbranded. It outlines requirements for active ingredients, their quantities, acid neutralizing capacity, and permissible combinations with other active ingredients. Labeling requirements, including statements of identity, indications, warnings, drug interaction precautions, and directions for use, are also detailed. Professional labeling for healthcare providers is also addressed.

What this part covers

  • Defines the scope for OTC antacid products, requiring adherence to general conditions in § 330.1.
  • Specifies permitted antacid active ingredients, including aluminum, bicarbonate, bismuth, calcium, citrate, glycine, magnesium, milk solids, phosphate, potassium, sodium, silicates, and tartrates, with maximum daily dosage limits for some.
  • Requires active ingredients to contribute at least 25% of the total acid neutralizing capacity, with a minimum of 5 mEq. for the finished product.
  • Allows antacids to be combined with non-laxative active ingredients like laxatives (to counteract constipation), analgesics (for concurrent symptoms like headache), and antiflatulents (for gas associated with indigestion).
  • Details specific labeling requirements for antacid products, including statement of identity, indications (heartburn, sour stomach, acid indigestion), warnings (dosage limits, constipation, laxative effect, milk allergy), drug interaction precautions, and directions for use.
  • Provides exemptions from certain general overdose warnings for specific antacid ingredients and combinations, while retaining the 'keep out of reach of children' warning.
  • Outlines professional labeling requirements for healthcare providers, including neutralizing capacity, and specific indications and warnings for certain ingredients (e.g., aluminum-containing antacids for renal patients).

Sections in Part 331

§ 331.1

Scope.

An over-the-counter antacid product in a form suitable for oral administration is generally recognized as safe and effective and is not misbranded if it meets each of the following conditions and each of the general conditions established in § 330.1 of this chapter.

§ 331.10

Antacid active ingredients.

(a) The active antacid ingredients of the product consist of one or more of the ingredients permitted in § 331.11 within any maximum daily dosage limit established, each ingredient is included at a level that contributes at least 25 percent of the total acid neutralizing capacity of the product, and the finished product contains at least 5 meq of acid neutralizing capacity as measured by the procedure provided in the United States Pharmacopeia 23/National Formulary 18. The method established in § 331.20 shall be used to determine the percent contribution of each antacid active ingredient. (b) This section does not apply to an antacid ingredient specifically added as a corrective to prevent a laxative or constipating effect. [39 FR 19874, June 4, 1974, as amended at 61 FR 4822, Feb. 8, 1996]

§ 331.11

Listing of specific active ingredients.

(a) Aluminum-containing active ingredients: (1) Basic aluminum carbonate gel. (2) Aluminum hydroxide (or as aluminum hydroxide-hexitol stabilized polymer, aluminum hydroxide-magnesium carbonate codried gel, aluminum hydroxide-magnesium trisilicate codried gel, aluminum-hydroxide sucrose powder hydrated). (3) Dihydroxyaluminum aminoacetate and dihydroxyaluminum aminoacetic acid. (4) Aluminum phosphate gel when used as part of an antacid combination product and contributing at least 25 percent of the total acid neutralizing capacity; maximum daily dosage limit is 8 grams. (5) Dihydroxyaluminum sodium carbonate. (b) Bicarbonate-containing active ingredients: Bicarbonate ion; maximum daily dosage limit 200 mEq. for persons up to 60 years old and 100 mEq. for persons 60 years or older. (c) Bismuth-containing active ingredients: (1) Bismuth aluminate. (2) Bismuth carbonate. (3) Bismuth subcarbonate. (4) Bismuth subgallate. (5) Bismuth subnitrate. (d) Calcium-containing active ingredients: Calcium, as carbonate or phosphate; maximum daily dosage limit 160 mEq. calcium (e.g., 8 grams calcium carbonate). (e) Citrate-containing active ingredients: Citrate ion, as citric acid…

§ 331.15

Combination with nonantacid active ingredients.

(a) An antacid may contain any generally recognized as safe and effective nonantacid laxative ingredient to correct for constipation caused by the antacid. No labeling claim of the laxative effect may be used for such a product. (b) An antacid may contain any generally recognized as safe and effective analgesic ingredient(s), if it is indicated for use solely for the concurrent symptoms involved, e.g., headache and acid indigestion, and is marketed in a form intended for ingestion as a solution. (c) An antacid may contain any generally recognized as safe and effective antiflatulent ingredient if it is indicated for use solely for the concurrent symptoms of gas associated with heartburn, sour stomach or acid indigestion.

§ 331.20

Determination of percent contribution of active ingredients.

To determine the percent contribution of an antacid active ingredient, place an accurately weighed amount of the antacid active ingredient equal to the amount present in a unit dose of the product into a 250-milliliter (mL) beaker. If wetting is desired, add not more than 5 mL of alcohol (neutralized to an apparent pH of 3.5), and mix to wet the sample thoroughly. Add 70 mL of water, and mix on a magnetic stirrer at 300 ±30 r.p.m. for 1 minute. Analyze the acid neutralizing capacity of the sample according to the procedure provided in the United States Pharmacopeia 23/National Formulary 18 and calculate the percent contribution of the antacid active ingredient in the total product as follows: Percent contribution = (Total mEq. Antacid Active Ingredient × 100)/(Total mEq. Antacid Product). [61 FR 4823, Feb. 8, 1996]

§ 331.21

Test modifications.

The formulation or mode of administration of certain products may require a modification of the United States Pharmacopeia 23/National Formulary 18 acid neutralizing capacity test. Any proposed modification and the data to support it shall be submitted as a petition under the rules established in § 10.30 of this chapter. All information submitted will be subject to the disclosure rules in part 20 of this chapter. [61 FR 4823, Feb. 8, 1996]

§ 331.30

Labeling of antacid products.

Statement of identity.(a) The labeling of the product contains the established name of the drug, if any, and identifies the product as an “antacid.” Indications.(b) The labeling of the product states, under the heading “Indications,” the following: “For the relief of” (optional, any or all of the following:) “heartburn,” “sour stomach,” and/or “acid indigestion” (which may be followed by the optional statement:) “and upset stomach associated with” (optional, as appropriate) “this symptom” or “these symptoms.” Other truthful and nonmisleading statements, describing only the indications for use that have been established and listed in this paragraph (b), may also be used, as provided in § 330.1(c)(2) of this chapter, subject to the provisions of section 502 of the act relating to misbranding and the prohibition in section 301(d) of the act against the introduction or delivery for introduction into interstate commerce of unapproved new drugs in violation of section 505(a) of the act. Warnings.(c) The labeling of the product contains the following warnings, under the heading “Warnings”, which may be combined but not rearranged to eliminate duplicative words or phrases if the…

§ 331.80

Professional labeling.

(a) The labeling of the product provided to health professionals (but not to the general public): (1) Shall contain the neutralizing capacity of the product as calculated using the procedure set forth in United States Pharmacopeia 23/National Formulary 18 expressed in terms of the dosage recommended per minimum time interval or, if the labeling recommends more than one dosage, in terms of the minimum dosage recommended per minimum time interval. (2) May contain an indication for the symptomatic relief of hyperacidity associated with the diagnosis of peptic ulcer, gastritis, peptic esophagitis, gastric hyperacidity, and hiatal hernia. For products containing basic aluminum carbonate gel identified in § 331.11(a)(1)—Indication.(3) “For the treatment, control, or management of hyperphosphatemia, or for use with a low phosphate diet to prevent formation of phosphate urinary stones, through the reduction of phosphates in the serum and urine.” For products containing aluminum identified in § 331.11(a)Warnings.(4) — (i) Prolonged use of aluminum-containing antacids in patients with renal failure may result in or worsen dialysis osteomalacia. Elevated tissue aluminum levels contribute…

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