A Bill of Materials (BOM) is a comprehensive list of all raw materials required to manufacture a parenteral batch. It includes every Active Pharmaceutical Ingredient (API), excipient, processing aid, coating material, and solvent (where applicable), together with their required quantities.
The BOM forms the basis for material procurement, dispensing, production planning, inventory management, and batch documentation. In pharmaceutical manufacturing, the BOM must accurately reflect the approved Master Formula Record (MFR) to ensure Good Manufacturing Practices (GMP) compliance and batch consistency.
APIs rarely assay exactly 100% on an as-is basis because they may contain moisture, residual solvents, or other volatile components. If assay correction is not applied, the finished tablets may contain less or more active ingredient than intended. Adjusting the API quantity according to the as-is assay ensures that every tablet contains the target label claim while maintaining compliance with pharmacopoeial specifications and regulatory requirements.
As-is basis calculates potency including all moisture and volatiles, while dried-basis removes water/volatiles, and anhydrous-basis further excludes bound water of hydration. Pharmaceutical batch calculations should generally be based on the as-is assay. Using a dried or anhydrous assay directly without conversion can lead to incorrect API quantities and inaccurate finished product assay.
The three primary tablet manufacturing methods are Direct Compression (DC), Wet Granulation (WG), and Dry Granulation (DG).
Tablet manufacturing is divided into distinct formulation and processing stages because no single operation can simultaneously achieve uniform drug distribution, excellent powder flow, adequate compressibility, optimal tablet hardness, efficient tablet ejection, and consistent product quality.
Purified water and many processing solvents are used only to facilitate granulation or coating and are intentionally removed during drying. Since these materials do not remain in the finished dosage form, they are generally excluded from the final tablet composition and theoretical fill volume/weight.
Manufacturers may use multiple API lots when a single lot is insufficient to complete production, inventory needs to be optimized, or approved stock rotation practices require the use of several qualified lots. All API lots should be approved, within their retest or expiry period, and documented according to GMP requirements.
A Master Formula Record generally includes: Product name, Batch size, Complete list of APIs and excipients, Approved supplier or manufacturer details, Theoretical composition, Manufacturing instructions, Equipment requirements, Processing stages, Environmental conditions, In-process controls, Yield calculations, Packaging instructions, and Quality specifications. It serves as the approved manufacturing document for routine commercial production under GMP.
Accurate batch composition ensures that every manufactured batch matches the approved formulation and meets predefined quality specifications. Incorrect material quantities may adversely affect Assay, Content uniformity, Dissolution, Tablet weight, Stability, and Regulatory compliance. Maintaining accurate batch composition supports data integrity, traceability, reproducibility, successful batch release, and inspection readiness under GMP.
Begin by entering the optional Product Name, the total Batch Size (number of tablets), and the required output decimal precision. Then add all Active Pharmaceutical Ingredients (APIs) and excipients under their appropriate manufacturing stages.
How should ingredients be assigned to different formulation stages?Each ingredient should be entered in the stage where it is actually applicable during manufacturing (e.g., Intra-granular, Binder, Blending, Lubrication, or Coating).
Can unused formulation stages be left blank?Yes. Only stages applicable to your manufacturing process need to be completed.
When should an ingredient be selected as an API?Select API only for Active Pharmaceutical Ingredient(s). This enables assay correction, single-lot or multi-lot calculations, and automatic quantity adjustment.
Use single-lot mode when the entire batch is manufactured from one API lot. If more than one qualified API lot contributes to the batch, use the Multiple API Lots option.
Which assay value should be entered for an API?Always enter the Assay (as-is) %. If the Certificate of Analysis reports assay on a dried, anhydrous, or ignited basis, first convert it to the equivalent as-is assay.
What does the Corrected mg/tab value represent?The Corrected mg/tab value is the adjusted quantity of API or excipients required per tablet after applying assay correction.
How does the compensating excipient option work?If API assay correction changes the API quantity, the pharmaceutical calculator automatically adjusts one selected compensating excipient to maintain the target fill volume/weight.
Use this option only for water or volatile solvents that evaporate during processing and are not present in the finished tablet. It is applicable only within the Binder and Coating stages.
Should water be entered as an ingredient in the final tablet composition?Yes, if it is used during granulation or coating. When marked as “evaporates”, it is included for process calculations but excluded from the final tablet composition since it does not remain in the finished product except traces.
Can coating materials be excluded for uncoated tablets?Yes. The Coating section is required only for coated tablets. For uncoated products, this section may simply be left blank.
Can the calculator be used for Direct Compression, Wet Granulation, and Dry Granulation formulations?Yes. The pharmaceutical calculator supports all three manufacturing methods.
The results table summarizes the complete Bill of Materials (BOM), including stage-wise ingredient quantities, corrected API amounts, overages, compensation adjustments, and total quantities required for the specified batch size.
Can the calculated batch composition be exported or printed?Yes. After calculation, the complete Bill of Materials (BOM) can be exported as CSV or Excel, or printed/saved as a PDF.
Why should the exported or printed report be reviewed before manufacturing?Although calculations are automated, users should always verify ingredient entries, API assay values, overages, compensation selections, manufacturing stages, and results.