Drug Manufacturing Considerations in the United States of America

The following white paper outlines FDA premise and guidelines to companies aspiring to engage in manufacturing of active pharmaceutical ingredients. The information presented is an introduction to the nuanced nature of the process and is not intended to be an authoritative treatise on the in and outs of the drug manufacturing rules and procedures.

The Center for Drug Evaluation and Research is a division of the U.S. Food and Drug Administration that monitors most drugs as defined in the Food, Drug, and Cosmetic Act. Some biological products are also legally considered drugs, but they are covered by the Center for Biologics Evaluation and Research. CDER established the Office of Pharmaceutical Quality (OPQ) to ensure a uniform drug quality program across all sites of manufacture, whether domestic or foreign,  and across all human drug product areas – new drugs and biologics, generics, and biosimilars—and also over-the-counter drugs and compounded drug products.

CGMP refers to the Current Good Manufacturing Practice regulations enforced by the FDA. CGMPs provide for systems that assure proper design, monitoring, and control of manufacturing processes and facilities. Adherence to the CGMP regulations assures the identity, strength, quality, and purity of drug products by requiring that manufacturers of medications adequately control manufacturing operations. This includes establishing strong quality management systems, obtaining appropriate quality raw materials, establishing robust operating procedures, detecting and investigating product quality deviations, and maintaining reliable testing laboratories. This formal system of controls at a pharmaceutical company, if adequately put into practice, helps to prevent instances of contamination, mix-ups, deviations, failures, and errors. This assures that drug products meet their quality standards.

General CGMP Practices for finished pharmaceuticals are outlined below.

1. Organization and Personnel
2. The quality control unit shall be responsible for approving or rejecting elements involved in the drug producing process, drug products manufactured, processed, packed, or held under contract by another company.
3. Each person engaged in the manufacture, processing, packing, or holding of a drug product shall have education, training, and experience, or any combination thereof, to enable that person to perform the assigned functions.
4. Personnel engaged in the manufacture, processing, packing, or holding of a drug product shall wear clean clothing appropriate for the duties they perform. 
5. Only personnel authorized by supervisory personnel shall enter those areas of the buildings and facilities designated as limited-access areas.
6. Personnel with any health conditions that may have an adverse effect on drug products should not involved in the drug producing process.
7. Consultants advising on the manufacture, processing, packing, or holding of drug products shall have sufficient education, training, and experience, or any combination thereof, to advise on the subject for which they are retained. 
8. Building and Facilities
9. Any building or buildings used in the manufacture, processing, packing, or holding of a drug product shall be of suitable size, construction and location to facilitate cleaning, maintenance, and proper operations.
10. There shall be separate or defined areas or such other control systems for the firm’s operations as are necessary to prevent contamination or mixups
11. Operations relating to the manufacture, processing, and packing of penicillin shall be performed in facilities separate from those used for other drug products for human use.
12. Adequate lighting shall be provided in all areas.
13. Adequate ventilation shall be provided.
14. Equipment for adequate control over air pressure, micro-organisms, dust, humidity, and temperature shall be provided when appropriate for the manufacture, processing, packing, or holding of a drug product.
15. Air filtration systems, including prefilters and particulate matter air filters, shall be used when appropriate on air supplies to production areas. 
16. Air-handling systems for the manufacture, processing, and packing of penicillin shall be completely separate from those for other drug products for human use.
17. Potable water shall be supplied under continuous positive pressure in a plumbing system free of defects that could contribute contamination to any drug product. 
18. Drains shall be of adequate size and, where connected directly to a sewer, shall be provided with an air break or other mechanical device to prevent back-siphonage.
19. Sewage, trash, and other refuse in and from the building and immediate premises shall be disposed of in a safe and sanitary manner.
20. Adequate washing facilities shall be provided, including hot and cold water, soap or detergent, air driers or single-service towels, and clean toilet facilities easily accesible to working areas.
21. 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.
22. There shall be written procedures assigning responsibility for sanitation and describing in sufficient detail
23. Sanitation procedures shall apply to work performed by contractors or temporary employees as well as work performed by full-time employees during the ordinary course of operations.
24. Any building used in the manufacture, processing, packing, or holding of a drug product shall be maintained in a good state of repair.
25. Equipment
26. Equipment used in the manufacture, processing, packing, or holding of a drug product shall be of appropriate design, adequate size, and suitably located to facilitate operations for its intended use and for its cleaning and maintenance.
27. Any substances required for operation, such as lubricants or coolants, shall not come into contact with components, drug product containers, closures, in-process materials, or drug products so as to alter the safety, identity, strength, quality, or purity of the drug product beyond the official or other established requirements.
28. Equipment and utensils shall be cleaned, maintained, and, as appropriate for the nature of the drug, sanitized and/or sterilized at appropriate intervals to prevent malfunctions or contamination 
29. Written procedures shall be established and followed for cleaning and maintenance of equipment
30. Automatic, mechanical, or electronic equipment or other types of equipment, including computers, or related systems that will perform a function satisfactorily, may be used in the manufacture, processing, packing, and holding of a drug product.
31. Appropriate controls shall be exercised over computer or related systems to assure that changes in master production and control records or other records are instituted only by authorized personnel.
32. Filters for liquid filtration used in the manufacture, processing, or packing of injectable drug products intended for human use shall not release fibers into such products. 
33. Control of Components and Drug Product Containers and Closures
34. There shall be written procedures describing in sufficient detail the receipt, identification, storage, handling, sampling, testing, and approval or rejection of components and drug product containers and closures; such written procedures shall be followed.
35. Each container or grouping of containers for components or drug product containers, or closures shall be identified with a distinctive code for each lot in each shipment received. 
36. Upon receipt and before acceptance, each container or grouping of containers of components, drug product containers, and closures shall be examined visually for appropriate labeling as to contents, container damage or broken seals, and contamination.
37.  Each lot of components, drug product containers, and closures shall be withheld from use until the lot has been sampled, tested, or examined, as appropriate, and released for use by the quality control unit.
38. Representative samples of each shipment of each lot shall be collected for testing or examination. Sample meets the appropriate specifications of identity, strength, quality, and purity shall be approved, otherwise will be rejected.
39. Components, drug product containers, and closures approved for use shall be rotated so that the oldest approved stock is used first. Deviation from this requirement is permitted if such deviation is temporary and appropriate.
40. Components, drug product containers, and closures shall be retested or reexamined as necessary, e.g., after storage for long periods or after exposure to air, heat or other conditions that might adversely affect the component, drug product container, or closure.
41. Rejected components, drug product containers, and closures shall be identified and controlled under a quarantine system designed to prevent their use in manufacturing or processing operations for which they are unsuitable.
42. Drug product containers and closures shall not be reactive, additive, or absorptive so as to alter the safety, identity, strength, quality, or purity of the drug beyond the official or established requirements.
43. Container closure systems shall provide adequate protection against foreseeable external factors in storage and use that can cause deterioration or contamination of the drug product.
44.  Drug product containers and closures shall be clean and, where indicated by the nature of the drug, sterilized and processed to remove pyrogenic properties to assure that they are suitable for their intended use.
45. Standards or specifications, methods of testing, and, where indicated, methods of cleaning, sterilizing, and processing to remove pyrogenic properties shall be written and followed for drug product containers and closures.
46. Production and Process Control
47. There shall be written procedures for production and process control designed to assure that the drug products have the identity, strength, quality, and purity they purport or are represented to possess. It should include:
48. The batch shall be formulated with the intent to provide not less than 100 percent of the labeled or established amount of active ingredient.
49. Components for drug product manufacturing shall be weighed, measured, or subdivided as appropriate, and the process should be supervised
50. Actual yields and percentages of theoretical yield shall be determined at the conclusion of each appropriate phase of manufacturing, processing, packaging, or holding of the drug product.
51. All compounding and storage containers, processing lines, and major equipment used during the production of a batch of a drug product shall be properly identified at all times to indicate their contents and, when necessary, the phase of processing of the batch.
52. Major equipment shall be identified by a distinctive identification number or code that shall be recorded in the batch production record to show the specific equipment used in the manufacture of each batch of a drug product.
53. To assure batch uniformity and integrity of drug products, written procedures shall be established and followed that describe the in-process controls, and tests, or examinations to be conducted on appropriate samples of in-process materials of each batch. 
54. Valid in-process specifications for such characteristics shall be consistent with drug product final specifications and shall be derived from previous acceptable process average and process variability estimates where possible and determined by the application of suitable statistical procedures where appropriate.
55. In-process materials shall be tested for identity, strength, quality, and purity as appropriate, and approved or rejected by the quality control unit, during the production process.
56. When appropriate, time limits for the completion of each phase of production shall be established to assure the quality of the drug product.
57.  Appropriate written procedures, designed to prevent objectionable microorganisms in drug products not required to be sterile, shall be established and followed.
58.  Written procedures shall be established and followed prescribing a system for reprocessing batches that do not conform to standards or specifications and the steps to be taken to insure that the reprocessed batches will conform with all established standards, specifications, and characteristics.
59. Reprocessing shall not be performed without the review and approval of the quality control unit.
60. Packaging and Labeling Control
61. There shall be written procedures describing in sufficient detail the receipt, identification, storage, handling, sampling, examination, and/or testing of labeling and packaging materials; such written procedures shall be followed. Labeling and packaging materials shall be representatively sampled, and examined or tested upon receipt and before use in packaging or labeling of a drug product.
62. Records shall be maintained for each shipment received of each different labeling and packaging material indicating receipt, examination or testing, and whether accepted or rejected.
63. Labels and other labeling materials for each different drug product, strength, dosage form, or quantity of contents shall be stored separately with suitable identification. Access to the storage area shall be limited to authorized personnel.
64. Use of gang-printed labeling for different drug products, or different strengths or net contents of the same drug product, is prohibited unless the labeling from gang-printed sheets is adequately differentiated by size, shape, or color.
65. If cut labeling is used for immediate container labels, individual unit cartons, or multiunit cartons containing immediate containers that are not packaged in individual unit cartons, packaging and labeling operations shall include one of the following special control procedures:
66. Dedication of labeling and packaging lines to each different strength of each different drug product;
67. Use of appropriate electronic or electromechanical equipment to conduct a 100-percent examination for correct labeling during or after completion of finishing operations; or
68. Use of visual inspection to conduct a 100-percent examination for correct labeling during or after completion of finishing operations for hand-applied labeling. Such examination shall be performed by one person and independently verified by a second person.
69. Use of any automated technique, including differentiation by labeling size and shape, that physically prevents incorrect labeling from being processed by labeling and packaging equipment.
70. Labeling materials issued for a batch shall be carefully examined for identity and conformity to the labeling specified in the master or batch production records.
71. Procedures shall be used to reconcile the quantities of labeling issued, used, and returned, and shall require evaluation of discrepancies found between the quantity of drug product finished and the quantity of labeling issued when such discrepancies are outside narrow preset limits based on historical operating data.
72. All excess labeling bearing lot or control numbers shall be destroyed.
73. Returned labeling shall be maintained and stored in a manner to prevent mixups and provide proper identification.
74. Procedures shall be written describing in sufficient detail the control procedures employed for the issuance of labeling; such written procedures shall be followed.
75. There shall be written procedures designed to assure that correct labels, labeling, and packaging materials are used for drug products; such written procedures shall be followed:
76. Prevention of mixups and cross-contamination by physical or spatial separation from operations on other drug products.
77.  Identification and handling of filled drug product containers that are set aside and held in unlabeled condition for future labeling operations to preclude mislabeling of individual containers, lots, or portions of lot
78. Identification of the drug product with a lot or control number that permits determination of the history of the manufacture and control of the batch.
79. Examination of packaging and labeling materials for suitability and correctness before packaging operations, and documentation of such examination in the batch production record.
80. Inspection of the packaging and labeling facilities immediately before use to assure that all drug products have been removed from previous operations.
81. Packaged and labeled products shall be examined during finishing operations to provide assurance that containers and packages in the lot have the correct label.
82. A representative sample of units shall be collected at the completion of finishing operations and shall be visually examined for correct labeling.
83. Results of these examinations shall be recorded in the batch production or control records.
84. To assure that a drug product meets applicable standards of identity, strength, quality, and purity at the time of use, it shall bear an expiration date determined by appropriate stability testing
85. If the drug product is to be reconstituted at the time of dispensing, its labeling shall bear expiration information for both the reconstituted and unreconstituted drug product
86. Homeopathic drug products, Allergenic extracts that are labeled “No U.S. Standard of Potency”, New drug products for investigational shall be exempt from the requirements of this section.
87. Holding and Distribution
88. Written procedures describing the warehousing of drug products shall be established and followed. 
89. Quarantine of drug products before release by the quality control unit.
90. Storage of drug products under appropriate conditions of temperature, humidity, and light so that the identity, strength, quality, and purity of the drug products are not affected.
91. Written procedures shall be established, and followed, describing the distribution of drug products. 
92. A procedure whereby the oldest approved stock of a drug product is distributed first. Deviation from this requirement is permitted if such deviation is temporary and appropriate.
93. A system by which the distribution of each lot of drug product can be readily determined to facilitate its recall if necessary.
94. Laboratory Controls
95. Laboratory controls shall include the establishment of scientifically sound and appropriate specifications, standards, sampling plans, and test procedures designed to assure that components, drug product containers, closures, in-process materials, labeling, and drug products conform to appropriate standards of identity, strength, quality, and purity. 
96. For each batch of drug product, there shall be appropriate laboratory determination of satisfactory conformance to final specifications for the drug product, including the identity and strength of each active ingredient, prior to release. 
97. There shall be appropriate laboratory testing, as necessary, of each batch of drug product required to be free of objectionable microorganisms.
98. Any sampling and testing plans shall be described in written procedures that shall include the method of sampling and the number of units per batch to be tested; such written procedure shall be followed.
99. Acceptance criteria for the sampling and testing conducted by the quality control unit shall be adequate to assure that batches of drug products meet each appropriate specification and appropriate statistical quality control criteria as a condition for their approval and release. The statistical quality control criteria shall include appropriate acceptance levels and/or appropriate rejection levels.
100. There shall be a written testing program designed to assess the stability characteristics of drug products:
101. Sample size and test intervals based on statistical criteria for each attribute examined to assure valid estimates of stability;
102. Storage conditions for samples retained for testing;
103. Reliable, meaningful, and specific test methods;
104. Testing of the drug product in the same container-closure system as that in which the drug product is marketed;
105. Testing of drug products for reconstitution at the time of dispensing (as directed in the labeling) as well as after they are reconstituted.
106. An adequate number of batches of each drug product shall be tested to determine an appropriate expiration date and a record of such data shall be maintained.
107. For each batch of drug product purporting to be sterile and/or pyrogen-free, there shall be appropriate laboratory testing to determine conformance to such requirements. The test procedures shall be in writing and shall be followed.
108. For each batch of ophthalmic ointment, there shall be appropriate testing to determine conformance to specifications regarding the presence of foreign particles and harsh or abrasive substances. The test procedures shall be in writing and shall be followed.
109. For each batch of controlled-release dosage form, there shall be appropriate laboratory testing to determine conformance to the specifications for the rate of release of each active ingredient. The test procedures shall be in writing and shall be followed.
110. An appropriately identified reserve sample that is representative of each lot in each shipment of each active ingredient shall be retained. The reserve sample consists of at least twice the quantity necessary for all tests required to determine whether the active ingredient meets its established specifications, except for sterility and pyrogen testing.
111. An appropriately identified reserve sample that is representative of each lot or batch of drug product shall be retained and stored under conditions consistent with product labeling. 
112. Animals used in testing components, in-process materials, or drug products for compliance with established specifications shall be maintained and controlled in a manner that assures their suitability for their intended use. They shall be identified, and adequate records shall be maintained showing the history of their use.
113. Records and Reports
114. Any production, control, or distribution record that is required to be maintained in compliance with this part and is specifically associated with a batch of a drug product shall be retained for at least 1 year after the expiration date of the batch or, in the case of certain OTC drug products lacking expiration dating 
115. All records required under this part, or copies of such records, shall be readily available for authorized inspection during the retention period at the establishment where the activities described in such records occurred. 
116. A written record of major equipment cleaning, maintenance (except routine maintenance such as lubrication and adjustments), and use shall be included in individual equipment logs that show the date, time, product, and lot number of each batch processed.
117. Component, drug product container, closure, and labeling records shall include:
118. The identity and quantity of each shipment of each lot of components, drug product containers, closures, and labeling; the name of the supplier; the supplier’s lot number(s) if known; the receiving code and the date of receipt.
119. The results of any test or examination performed and the conclusion derived therefrom
120. An individual inventory record of each component, drug product container, and closure and, for each component, a reconciliation of the use of each lot of such component. The inventory record shall contain sufficient information to allow determination of any batch or lot of drug product associated with the use of each component, drug product container, and closure.
121. Documentation of the examination and review of labels and labeling for conformity with established specifications
122. The disposition of rejected components, drug product containers, closure, and labeling.
123. Master production and control records for each drug product, including each batch size thereof, shall be prepared, dated, and signed (full signature, handwritten) by one person and independently checked, dated, and signed by a second person.
124. Master production and control records shall include:
125. The name and strength of the product and a description of the dosage form;
126. The name and weight or measure of each active ingredient per dosage unit or per unit of weight or measure of the drug product, and a statement of the total weight or measure of any dosage unit;
127. A complete list of components designated by names or codes sufficiently specific to indicate any special quality characteristic;
128. An accurate statement of the weight or measure of each component, using the same weight system (metric, avoirdupois, or apothecary) for each component. Reasonable variations may be permitted, however, in the amount of components necessary for the preparation in the dosage form, provided they are justified in the master production and control records;
129. A statement concerning any calculated excess of component;
130. A statement of theoretical weight or measure at appropriate phases of processing;
131. A statement of theoretical yield, including the maximum and minimum percentages of theoretical yield beyond requirement
132. A description of the drug product containers, closures, and packaging materials, including a specimen or copy of each label and all other labeling signed and dated by the person or persons responsible for approval of such labeling;
133. Complete manufacturing and control instructions, sampling and testing procedures, specifications, special notations, and precautions to be followed.
134. Batch production and control records include:
135. An accurate reproduction of the appropriate master production or control record, checked for accuracy, dated, and signed;
136. Documentation that each significant step in the manufacture, processing, packing, or holding of the batch was accomplished
137. All drug product production and control records, including those for packaging and labeling, shall be reviewed and approved by the quality control unit to determine compliance with all established, approved written procedures before a batch is released or distributed. Any unexplained discrepancy (including a percentage of theoretical yield exceeding the maximum or minimum percentages established in master production and control records) or the failure of a batch or any of its components to meet any of its specifications shall be thoroughly investigated, whether or not the batch has already been distributed. The investigation shall extend to other batches of the same drug product and other drug products that may have been associated with the specific failure or discrepancy. A written record of the investigation shall be made and shall include the conclusions and followup.
138. Laboratory records shall include complete data derived from all tests necessary to assure compliance with established specifications and standards, including examinations and assays
139. Distribution records shall contain the name and strength of the product and description of the dosage form, name and address of the consignee, date and quantity shipped, and lot or control number of the drug product. For compressed medical gas products, distribution records are not required to contain lot or control numbers.
140. Returned and Salvaged Drug Products
141. Returned drug products shall be identified as such and held. If the conditions under which returned drug products have been held, stored, or shipped before or during their return, or if the condition of the drug product, its container, carton, or labeling, as a result of storage or shipping, casts doubt on the safety, identity, strength, quality or purity of the drug product, the returned drug product shall be destroyed unless examination, testing, or other investigations prove the drug product meets appropriate standards of safety, identity, strength, quality, or purity.
142. Drug products that have been subjected to improper storage conditions including extremes in temperature, humidity, smoke, fumes, pressure, age, or radiation due to natural disasters, fires, accidents, or equipment failures shall not be salvaged and returned to the marketplace.

Online References:

1. https://www.fda.gov/drugs/development-approval-process-drugs/pharmaceutical-quality-resources
2. https://www.fdareader.com/blog/introduction-to-gmps
3. https://www.naturalproductsinsider.com/manufacturing/cost-gmp-compliance
4. https://www.registrarcorp.com/fda-announces-higher-re-inspection-fees-for-fy-2020/
5. https://public-library.safetyculture.io/products/general-gmp-checklist?src=sc&amp_dev=d8263e90-79f2-4a4e-ae6b-c11fe32f727aR?src=sc&amp_dev=281588f7-4a3c-419c-ad27-a5bcc5fc3612R