REFERENCE FORMULA
Reference formula
Reference basis: 100 mL
| Ingredient | Source quantity | Scaled quantity |
|---|---|---|
| Sodium bicarbonate | 5 g | — |
| Glycerol | 30 mL | — |
| Freshly boiled and cooled purified water | q.s. ad 100 mL | — |
REFERENCE FORMULA SCALING
Proportional quantities of the same formula
Arithmetic aid. It does not change strength, dose, method or BUD and does not authorise compounding.
Theoretical calculation sheet
CGR-BP-021 · Sodium Bicarbonate Ear Drops
Not an approved master record or batch release. BUD is not calculated.
| Ingredient | Reference | Calculated | Lot | Actual quantity |
|---|
Prerequisite formulations
No separate prerequisite monograph is listed.
Documentation
Preparation description
Ear solution or drops: Sodium Bicarbonate Ear Drops. Additional appearance criteria are not established by the specific text reviewed. [1]
Action and use
The source defines the ear solution or drops and its composition. It does not provide a specific clinical indication or dosing regimen for the complete mixture. [1]
Specifications
NaHCO3: 4.75-5.25% w/v; mass/mL 1.10-1.12 g [1]
Light
Finished-product photostability is not specified. Any required container light protection is stated under Storage. [1]
Air and oxidation
No oxidative stability study of the finished mixture or inert-atmosphere requirement is provided. Use the source container. [1]
Water and solubility
Humidity
Temperature
Heating sodium bicarbonate can cause conversion to sodium carbonate, in solid material or solution. [3]
pH and compatibility
Sodium bicarbonate reacts with acids, releasing CO2. [3]
Other interactions
Glycerol: hazardous reaction with strong oxidising agents. [2]
Ingredient-specific information
Glycerol: clear, colourless, viscous and strongly hygroscopic liquid. It mixes with water but is practically insoluble in fixed and essential oils.
Sodium bicarbonate: white crystalline powder. Limit heat and moisture; PA005 recommends cooling unused aqueous solutions, subject to the finished formula’s requirements.
Glycerol: retain original manufacturer, lot and reliable certificate. For the applicable raw materials, FDA describes DEG and EG testing, each limited to 0.10% under the relevant monograph. This is a raw-material limit. [2], [3], [5]
Sodium bicarbonate: white crystalline powder. Limit heat and moisture; PA005 recommends cooling unused aqueous solutions, subject to the finished formula’s requirements.
Glycerol: retain original manufacturer, lot and reliable certificate. For the applicable raw materials, FDA describes DEG and EG testing, each limited to 0.10% under the relevant monograph. This is a raw-material limit. [2], [3], [5]
Staff protection
Risk assessment
Reference batch: 100 mL. First ingredient: Sodium bicarbonate, 5 g. Independently check chemical form, units and every scale conversion before weighing.
Confirm that the application does not require a sterile product and that tympanic-membrane status permits the prescribed formula. Otic labelling must prevent confusion with eye drops.
For the local assessment record quantity per preparation, work frequency, duration of open handling, potential exposure routes and effectiveness of controls. These are assessment inputs; no fictitious final risk score is assigned.
Release checkpoint: confirm final volume or mass at the reference temperature, intended clarity or dispersion, and specified container/closure. Do not equate grams and millilitres without a justified density. [1], [9], [11]
Confirm that the application does not require a sterile product and that tympanic-membrane status permits the prescribed formula. Otic labelling must prevent confusion with eye drops.
For the local assessment record quantity per preparation, work frequency, duration of open handling, potential exposure routes and effectiveness of controls. These are assessment inputs; no fictitious final risk score is assigned.
Release checkpoint: confirm final volume or mass at the reference temperature, intended clarity or dispersion, and specified container/closure. Do not equate grams and millilitres without a justified density. [1], [9], [11]
Compounding conditions
BUD rationale
No specific experimental period was located covering the complete exact formulation, container and microbiological suitability.
Selected conservative general rule: up to 14 days at 2–8 °C for an aqueous form without adequately established preservation. Refrigeration must not cause precipitation, irreversible separation or other loss of suitability. If that condition fails, do not apply 14 days at room temperature; obtain specific short-use evidence.
Use-by date = the earliest allowed date from preparation plus selected period, ingredient expiries and any shorter supported limit. In-use dating never extends overall BUD. Complete the actual date for the batch after the required checks.
A default is a conservative dating limit, not experimental proof of batch stability. Its category depends on final composition, preservation and permitted temperatures. Water percentage or loss on drying does not determine aw. Document using SOP-014/F-006; use SOP-017/F-012 for specific aw evidence.
USP clarification: aw measurement is not required for every nonsterile preparation. Category assignment may use the exact composition and relevant representative examples; an uncertain or borderline formulation is best assessed by a suitable specific measurement. This edition contains no measured aw or released batch. The final preparation generally must not outlast the remaining BUD of its compounded bases/intermediates. An exception requires specific justification that physical, chemical and microbiological quality is not adversely affected. Record the final limit, intermediate preparation dates and their actual expiry dates separately. [1], [8], [10], [12]
Selected conservative general rule: up to 14 days at 2–8 °C for an aqueous form without adequately established preservation. Refrigeration must not cause precipitation, irreversible separation or other loss of suitability. If that condition fails, do not apply 14 days at room temperature; obtain specific short-use evidence.
Use-by date = the earliest allowed date from preparation plus selected period, ingredient expiries and any shorter supported limit. In-use dating never extends overall BUD. Complete the actual date for the batch after the required checks.
A default is a conservative dating limit, not experimental proof of batch stability. Its category depends on final composition, preservation and permitted temperatures. Water percentage or loss on drying does not determine aw. Document using SOP-014/F-006; use SOP-017/F-012 for specific aw evidence.
USP clarification: aw measurement is not required for every nonsterile preparation. Category assignment may use the exact composition and relevant representative examples; an uncertain or borderline formulation is best assessed by a suitable specific measurement. This edition contains no measured aw or released batch. The final preparation generally must not outlast the remaining BUD of its compounded bases/intermediates. An exception requires specific justification that physical, chemical and microbiological quality is not adversely affected. Record the final limit, intermediate preparation dates and their actual expiry dates separately. [1], [8], [10], [12]
Prerequisites
No separately registered base is required. Any commercial vehicle remains the exact named product in the formula table. [1]
Equipment
Balance with suitable minimum weight, mortar/pestle or homogeniser, mixing vessels, spatulas, thermometer for heated processes and volumetric equipment for mL quantities. [1]
Compounding method
Dissolve the salt in about 60 mL water. Add glycerol, make up to 100 mL with water and mix. The source requires recent preparation. [1]
Observations
“Recently prepared” is not a numerical BUD. [1]
Container and packaging
Selection for local assessment: well-closed bottle compatible with the liquid. Check cleanliness, integrity, closure and material compatibility before filling. The specific monograph does not validate a particular commercial container. [1]
Quality control
Dilute 5 mL with 20 mL water and titrate with 0.1 M HCl using methyl orange–xylene cyanol FF. Each mL equals 8.401 mg NaHCO3.
Polyol incoming QC: pharmacies test each lot or ensure documented testing by a reliable supplier, as described by FDA. IR identity alone does not exclude DEG/EG.
Record the method, acceptance criterion, actual result and reviewer separately in F-005. A critical specification failure requires quarantine and investigation under SOP-015; retesting needs justification. [1], [5], [11]
Polyol incoming QC: pharmacies test each lot or ensure documented testing by a reliable supplier, as described by FDA. IR identity alone does not exclude DEG/EG.
Record the method, acceptance criterion, actual result and reviewer separately in F-005. A critical specification failure requires quarantine and investigation under SOP-015; retesting needs justification. [1], [5], [11]
Storage
Dispensing
Dispense with a clear route, strength and use-by date. Complete amount per application and frequency from the prescription. [1]
Labelling
v9_controls
The numeric value is a literature reference ceiling subject to its specific conditions. No actual batch BUD has been assigned and no aw measurements have been produced. The exact formula, prerequisites, container, storage and quality evidence require approval for the actual application. The BUD clock starts when compounding begins. Use the shortest applicable supported limit and assess in-use dating separately. USP categories are a technical framework and are not presented as Greek legislation.
Independent Greek/English adaptation and organisation of facts from the cited source. This is not an official translation or publisher endorsement.
Sources and references
- British Pharmacopoeia 2016 — Sodium Bicarbonate Ear Drops2016PDF pp. 1–1; user-supplied BP extract; URL is publisher catalogue, not the licensed full monographmaster formula2026-09-10
- FN/2003/PA/013 GLICEROLΔιαθέσιμο κείμενο / Retrieved textPDF pp. 1–2raw material or occupational2026-09-10
- FN/2003/PA/005 BICARBONATO DE SODIOΔιαθέσιμο κείμενο / Retrieved textPDF pp. 1–2raw material or occupational2026-09-10
- PN/L/PG/002/00 INDUMENTARIAΔιαθέσιμο κείμενο / Retrieved textPDF pp. 1–5general staff protection2026-09-10
- FDA — Testing of Glycerin, Propylene Glycol, Maltitol Solution, Hydrogenated Starch Hydrolysate, Sorbitol Solution, and Other High-Risk Drug Components for Diethylene Glycol and Ethylene GlycolMay 2023, revision 1Recommendations; section on pharmacy compoundingraw material quality2026-09-12
- ASHP — USP <795> Key Changes2023pp. 1–3: scope, water activity and staff precautionsprofessional guidance; not the licensed USP chapter2026-09-12
- Texas State Board of Pharmacy — adopted 22 TAC §291.131, nonsterile compoundingTexas Register, 7 June 2024Beyond-use dating: aw categories, 14/35/90/180 days, limits and extensionspublic regulatory implementation of USP <795> BUD framework; not Greek law2026-09-12
- Illinois IDFPR — Nonsterile Compounding Self-Inspection ReportPublic checklist, retrieved 12 September 2026pp. 15–16, Establishing beyond-use datesPublic regulatory implementation of USP <795>; not Greek law; general limits and requirements for extension2026-09-12
- NIOSH — Managing Hazardous Drug Exposures: Information for Healthcare Settings2023; DHHS (NIOSH) 2023-130Risk assessment; printed pp. 27–33, activity/formulation control tableWorkplace exposure, hierarchy of controls and activity-specific PPE; US government public-domain document2026-09-12
- USP — Compounding Standards and Beyond-Use Dates, 2022 updateNovember 2022, published by USP; public copy hosted by Mississippi Boardpp. 1–2; nonsterile tableRisk-based default categories; not product-specific stability or Greek law2026-09-12
- PIC/S — Guide to Good Practices for the Preparation of Medicinal Products in Healthcare EstablishmentsPE 010-4, 1 March 2014Chapters 1–9; Annex 2 (nonsterile liquids, creams, ointments)Professional quality-system framework; not automatic national legal adoption or certification2026-09-12
- USP — General Chapter <795> FAQsUpdated 1 November 2023Questions 52, 54–56, 60–62; PDF pp. 11–14Primary clarification of aw classification, extension prerequisites and compounded-component BUDs; not automatic Greek legal adoption2026-10-14