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Get CFR Regulation

Retrieve detailed information about a specific Code of Federal Regulations (CFR) section including full text, subsections, ICH guideline cross-references, and evidence framework.

Endpoint​

GET /v1/kg/regulations/\{cfr\}

Base URL: https://api.ctwise.ai

Authorization Tier: Starter+

Request​

Path Parameters​

ParameterTypeRequiredDescription
cfrstringYesCFR section identifier in format: 21-CFR-XXX.YY (e.g., 21-CFR-211.56) (path parameter: \{cfr\})

Query Parameters​

ParameterTypeRequiredDescription
include_subsectionsbooleanNoInclude all subsections (default: true)
include_ich_referencesbooleanNoInclude related ICH guideline sections (default: true)
include_related_cfrbooleanNoInclude related CFR sections (default: false)

Example Request​

curl -X GET "https://api.ctwise.ai/v1/kg/regulations/21-CFR-211.56?include_subsections=true&include_ich_references=true" \
  -H "Content-Type: application/json"

Response​

Success (200)​

{
  "regulation": {
    "cfr_section": "21 CFR 211.56",
    "part": "211",
    "subpart": "C",
    "section": "56",
    "title": "Sanitation",
    "full_citation": "Title 21 - Food and Drugs, Chapter I - Food and Drug Administration, Subchapter C - Drugs: General, Part 211 - Current Good Manufacturing Practice for Finished Pharmaceuticals, Subpart C - Buildings and Facilities, Section 211.56 - Sanitation",
    "product_types": ["drug"],
    "effective_date": "1978-09-29",
    "last_updated": "2024-04-01"
  },
  "full_text": {
    "summary": "Any building used in the manufacture, processing, packing, or holding of a drug product shall be maintained in a clean and sanitary condition. Any such building shall be free of infestation by rodents, birds, insects, and other vermin (other than laboratory animals). Trash and organic waste matter shall be held and disposed of in a timely and sanitary manner.",
    "subsections": [
      {
        "subsection": "(a)",
        "text": "Any building used in the manufacture, processing, packing, or holding of a drug product shall be maintained in a clean and sanitary condition, any such building shall be free of infestation by rodents, birds, insects, and other vermin (other than laboratory animals)."
      },
      {
        "subsection": "(b)",
        "text": "Trash and organic waste matter shall be held and disposed of in a timely and sanitary manner."
      },
      {
        "subsection": "(c)",
        "text": "Written procedures shall be established and followed for cleaning and maintenance of buildings used in the manufacture, processing, packing, or holding of a drug product."
      },
      {
        "subsection": "(d)",
        "text": "Written procedures shall be established and followed for the use of suitable rodenticides, insecticides, fungicides, fumigating agents, and cleaning and sanitizing agents. Such written procedures shall be designed to prevent the contamination of equipment, components, drug product containers, closures, packaging, labeling materials, or drug products."
      }
    ]
  },
  "ich_cross_references": [
    {
      "guideline": "Q7",
      "guideline_title": "Good Manufacturing Practice Guide for Active Pharmaceutical Ingredients",
      "sections": [
        {
          "section": "12.30",
          "title": "Sanitation and Maintenance",
          "text": "Sanitation and maintenance programs should be established to ensure that buildings and equipment are properly maintained and that adequate sanitation procedures are in place.",
          "relevance": "direct",
          "mapping_rationale": "ICH Q7 Section 12.30 directly corresponds to 21 CFR 211.56 requirements for sanitation in manufacturing facilities"
        },
        {
          "section": "12.31",
          "title": "Cleaning and Sanitation",
          "text": "Detailed written procedures should be established and followed for cleaning and sanitation of buildings and facilities.",
          "relevance": "direct",
          "mapping_rationale": "Reinforces written procedure requirements in 21 CFR 211.56(c)"
        }
      ]
    },
    {
      "guideline": "Q10",
      "guideline_title": "Pharmaceutical Quality System",
      "sections": [
        {
          "section": "2.3",
          "title": "Management of Outsourced Activities and Purchased Materials",
          "text": "The pharmaceutical quality system should ensure the control of outsourced activities and purchased materials through quality agreements.",
          "relevance": "indirect",
          "mapping_rationale": "Applicable when sanitation services are outsourced; quality system should verify contractor compliance with 21 CFR 211.56"
        }
      ]
    }
  ],
  "related_regulations": [
    {
      "cfr_section": "21 CFR 211.42",
      "title": "Design and construction features",
      "relationship": "prerequisite",
      "rationale": "Building design must support sanitation requirements"
    },
    {
      "cfr_section": "21 CFR 211.25",
      "title": "Personnel qualifications",
      "relationship": "supporting",
      "rationale": "Personnel must be qualified to execute sanitation procedures"
    }
  ],
  "common_citations": {
    "total_483_citations": 1247,
    "time_period": "2020-2024",
    "citation_rank": 3,
    "trending": "stable",
    "most_common_deficiency_types": [
      "Inadequate pest control programs",
      "Lack of written sanitation procedures",
      "Evidence of pest infestation",
      "Improper waste disposal procedures"
    ]
  },
  "evidence_sources": [
    {
      "source_type": "cfr_regulations",
      "source_id": "cfr-title21-2024-04-01",
      "retrieval_method": "direct_lookup",
      "confidence": 1.0,
      "publication_date": "2024-04-01",
      "authority": "FDA/US Government Publishing Office"
    },
    {
      "source_type": "ich_guidelines",
      "source_id": "ich-q7-2024",
      "retrieval_method": "cross_reference_mapping",
      "confidence": 1.0,
      "publication_date": "2024-01-15",
      "authority": "International Council for Harmonisation"
    },
    {
      "source_type": "fda_483_database",
      "source_id": "fda-483-analytics-2020-2024",
      "retrieval_method": "aggregation",
      "confidence": 0.98,
      "data_period": "2020-2024"
    }
  ],
  "evidence_chain": {
    "chain_integrity": "verified",
    "evidence_coverage": 1.0,
    "provenance_complete": true,
    "sources_verified": 3,
    "last_verification_date": "2024-04-01"
  },
  "response_metadata": {
    "cfr_database_version": "2024.04.01",
    "ich_database_version": "2024.01",
    "processing_timestamp": "2026-03-03T12:00:00Z",
    "resolver_version": "1.0.0",
    "lambda_request_id": "def456-ghi789"
  }
}

Response Fields​

FieldTypeDescription
regulationobjectCore regulation metadata
regulation.cfr_sectionstringStandard CFR citation format (e.g., "21 CFR 211.56")
regulation.partstringCFR Part number
regulation.subpartstringCFR Subpart letter
regulation.sectionstringSection number
regulation.titlestringOfficial section title
regulation.full_citationstringComplete hierarchical citation
regulation.product_typesstring[]Applicable product types: drug, food, device, api
regulation.effective_datestringDate regulation became effective (ISO 8601)
regulation.last_updatedstringMost recent update date (ISO 8601)
full_textobjectComplete regulation text
full_text.summarystringMain section text
full_text.subsectionsarrayAll subsections with individual text
full_text.subsections[].subsectionstringSubsection identifier (e.g., "(a)", "(b)")
full_text.subsections[].textstringFull subsection text
ich_cross_referencesarrayRelated ICH guideline sections
ich_cross_references[].guidelinestringICH guideline identifier (Q7, Q9, Q10)
ich_cross_references[].guideline_titlestringFull guideline title
ich_cross_references[].sectionsarrayRelated sections from the guideline
ich_cross_references[].sections[].sectionstringSection number
ich_cross_references[].sections[].titlestringSection title
ich_cross_references[].sections[].textstringSection content excerpt
ich_cross_references[].sections[].relevancestringdirect or indirect relevance
ich_cross_references[].sections[].mapping_rationalestringExplanation of the cross-reference relationship
related_regulationsarrayRelated CFR sections (if include_related_cfr=true)
related_regulations[].cfr_sectionstringRelated CFR citation
related_regulations[].titlestringRelated regulation title
related_regulations[].relationshipstringType of relationship: prerequisite, supporting, related
related_regulations[].rationalestringExplanation of relationship
common_citationsobjectFDA 483 citation frequency data
common_citations.total_483_citationsnumberTotal times cited in FDA 483s (2020-2024)
common_citations.citation_ranknumberRank by frequency (1 = most cited)
common_citations.trendingstringTrend: increasing, stable, decreasing
common_citations.most_common_deficiency_typesstring[]Common deficiency patterns
evidence_sourcesarrayAll evidence sources used
evidence_chainobjectEvidence integrity metrics
response_metadataobjectProcessing metadata and versions

Error Responses​

StatusCauseResponse ExampleResolution
400Invalid CFR format{"error": "Invalid CFR format. Use format: 21-CFR-XXX.YY"}Use correct format (e.g., 21-CFR-211.56)
404CFR section not found{"error": "CFR section not found: 21-CFR-999.99"}Verify CFR section exists in Title 21
500Retrieval failure{"error": "Internal retrieval error"}Retry request; check Lambda logs

CFR Format Examples​

Input FormatValidExample
21-CFR-211.56YesRecommended format
21CFR211.56YesAlternative format (auto-normalized)
211.56YesShort format (assumes Title 21)
21 CFR 211.56NoSpaces not supported in path parameter
CFR-211-56NoIncorrect delimiter placement

Supported CFR Parts​

PartDescriptionExample Sections
211Current Good Manufacturing Practice for Finished Pharmaceuticals211.56, 211.86, 211.160
210Current Good Manufacturing Practice in Manufacturing, Processing, Packing, or Holding of Drugs; General210.1, 210.2, 210.3
314Applications for FDA Approval to Market a New Drug314.50, 314.80, 314.81
312Investigational New Drug Application312.20, 312.32, 312.50
110Current Good Manufacturing Practice in Manufacturing, Packing, or Holding Human Food110.10, 110.20, 110.35
820Quality System Regulation (Medical Devices)820.20, 820.30, 820.70

Usage Examples​

Basic CFR Lookup​

curl -X GET "https://api.ctwise.ai/v1/kg/regulations/21-CFR-211.86" \
  -H "Content-Type: application/json"
curl -X GET "https://api.ctwise.ai/v1/kg/regulations/21-CFR-211.160?include_subsections=true&include_ich_references=true&include_related_cfr=true" \
  -H "Content-Type: application/json"

Minimal Response (No Cross-References)​

curl -X GET "https://api.ctwise.ai/v1/kg/regulations/21-CFR-211.25?include_ich_references=false" \
  -H "Content-Type: application/json"

Citation Frequency Rankings​

Top 10 most cited CFR sections in FDA 483 observations (2020-2024):

RankCFR SectionTitleCitationsTrend
121 CFR 211.160General requirements (Laboratory Controls)3,247Stable
221 CFR 211.192Production record review2,891Increasing
321 CFR 211.56Sanitation1,247Stable
421 CFR 211.67Equipment cleaning and maintenance1,156Decreasing
521 CFR 211.100Written procedures; deviations1,089Increasing
621 CFR 211.86Use of components987Stable
721 CFR 211.110Sampling and testing of in-process materials876Stable
821 CFR 211.165Testing and release for distribution845Increasing
921 CFR 211.194Laboratory records812Stable
1021 CFR 211.22Responsibilities of quality control unit789Increasing

Notes​

  • Data Currency: CFR text updated quarterly from official GPO publications
  • Evidence Framework: All responses include full provenance (P0 non-negotiable)
  • ICH Mappings: Curated by regulatory affairs SMEs; verified against official guidance
  • Citation Data: Based on 15,000+ FDA 483 observations from 2020-2024
  • Product Type Coverage: Supports drugs (21 CFR 210-226), devices (21 CFR 820), food (21 CFR 110)
  • Response Time: Typically 100-300ms (cached responses: <50ms)
  • Cache Duration: 7 days for regulation text; 24 hours for citation statistics
  • Rate Limiting: Starter: 1,000 requests/day; Pro: 10,000 requests/day; Enterprise: unlimited

483 Intelligence (Cross-Domain)​