REFERENCE FORMULA
Reference formula
Reference basis: 100 mL
| Ingredient | Source quantity | Scaled quantity |
|---|---|---|
| Glacial acetic acid | 0.66 mL | — |
| Ethanol 70%, AEMPS specification | 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-ES-024 · Acetic Acid Ear Drops AEMPS
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
Clear, colourless solution. [1]
Action and use
Acidifying ear preparation. [1]
Specifications
Clear, colourless solution. [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
No quantitative hydrolytic stability limit is given for this formula. Retain the prescribed water amount and quality. [1]
Humidity
No numerical relative-humidity limit is given for the finished product. Prevent raw-material wetting and condensation entering the container. [1]
Temperature
For the finished product the source specifies:
Well-closed dropper bottle; <30 °C. [1]
Well-closed dropper bottle; <30 °C. [1]
pH and compatibility
No finished-product pH range is specified. Do not add a pH adjuster without a supported formula change. [1]
Other interactions
Ethanol is incompatible with strong oxidants. [2]
Ingredient-specific information
Identity and weighing basis:
• Glacial acetic acid: 0.66 mL.
• Ethanol 70%, AEMPS specification: q.s. ad 100 mL.
The specified chemical forms/grades belong to the exact source formula. [1]
• Glacial acetic acid: 0.66 mL.
• Ethanol 70%, AEMPS specification: q.s. ad 100 mL.
The specified chemical forms/grades belong to the exact source formula. [1]
Staff protection
Glacial acetic acid requires careful handling because of irritation; select specific PPE from the SDS for the concentration used.
Clean long-sleeved laboratory clothing, hair covering and gloves during handling; change gloves after contamination or damage.
Contain powder during weighing and trituration and use eye protection; select respiratory protection for the actual exposure. [3], [4], [7]
Clean long-sleeved laboratory clothing, hair covering and gloves during handling; change gloves after contamination or damage.
Contain powder during weighing and trituration and use eye protection; select respiratory protection for the actual exposure. [3], [4], [7]
Risk assessment
Ethanol: flammable vapour; control ignition sources and provide suitable ventilation. Final classification depends on concentration/mixture.
Reference batch: 100 mL. First ingredient: Glacial acetic acid, 0.66 mL. 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.
Volatile solvent in this formula: Ethanol 70%, AEMPS specification q.s. ad 100 mL. Exclude ignition sources and minimise vapours/open evaporation. Check ventilation, electrical equipment and container compatibility with the specific solvent.
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], [2], [3], [4], [7], [10], [12]
Reference batch: 100 mL. First ingredient: Glacial acetic acid, 0.66 mL. 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.
Volatile solvent in this formula: Ethanol 70%, AEMPS specification q.s. ad 100 mL. Exclude ignition sources and minimise vapours/open evaporation. Check ventilation, electrical equipment and container compatibility with the specific solvent.
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], [2], [3], [4], [7], [10], [12]
Compounding conditions
The corresponding AEMPS SOP specifies room temperature 25 ± 5°C and relative humidity ≤60%, unless the particular formula requires otherwise. This is the work environment, not processing or storage temperature.
Follow the addition sequence, temperatures and times stated under Preparation Procedure. The specific monograph is not a complete qualification of the local facility/equipment. [1], [5]
Follow the addition sequence, temperatures and times stated under Preparation Procedure. The specific monograph is not a complete qualification of the local facility/equipment. [1], [5]
BUD rationale
Period reported by source: 3 months.
This duration is a specific formulary/source instruction. This review did not verify a complete primary study establishing chemical, physical and microbiological extension for the same finished formulation.
Selected general rule: up to 35 days for an aqueous form appropriately preserved in its final composition and pH. Use 20–25 °C, or 2–8 °C only where permitted/required by the source and compatible with the dosage form. A preservative name is insufficient if it is diluted, inactivated or partitioned into another phase.
The reference-policy ceiling in this edition is the shorter of the source period above and the general ceiling. Extension needs matching active/excipients/strength, container, temperature, a stability-indicating method and the required microbiological evidence for aqueous extension. An applicable official USP–NF compounded monograph is assessed separately in its complete text.
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 does not require water-activity measurement for every nonsterile preparation. A justified classification of the actual formulation may guide dating; record it explicitly as inferred, not measured. Uncertain or borderline classification requires specific evidence or a suitable measurement. Finished-product dating does not outlast the available dating of previously compounded components/bases unless adequate specific evidence for the exact finished preparation has been formally adopted. [1], [8], [9], [11], [13]
This duration is a specific formulary/source instruction. This review did not verify a complete primary study establishing chemical, physical and microbiological extension for the same finished formulation.
Selected general rule: up to 35 days for an aqueous form appropriately preserved in its final composition and pH. Use 20–25 °C, or 2–8 °C only where permitted/required by the source and compatible with the dosage form. A preservative name is insufficient if it is diluted, inactivated or partitioned into another phase.
The reference-policy ceiling in this edition is the shorter of the source period above and the general ceiling. Extension needs matching active/excipients/strength, container, temperature, a stability-indicating method and the required microbiological evidence for aqueous extension. An applicable official USP–NF compounded monograph is assessed separately in its complete text.
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 does not require water-activity measurement for every nonsterile preparation. A justified classification of the actual formulation may guide dating; record it explicitly as inferred, not measured. Uncertain or borderline classification requires specific evidence or a suitable measurement. Finished-product dating does not outlast the available dating of previously compounded components/bases unless adequate specific evidence for the exact finished preparation has been formally adopted. [1], [8], [9], [11], [13]
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
Mix acid with ethanol 70% to final volume. [1]
Observations
Contraindicated with tympanic perforation or hypersensitivity. [1]
Container and packaging
Well-closed dropper bottle; <30 °C. [1]
Quality control
Clear, colourless solution.
Additional tests from the referenced SOP:
Appearance and mass/volume. For batches: colour, clarity/opalescence, relative density, pH and microbiological testing RFE 5.1.4.
pH under PN/CP/001: normally test the untreated sample unless otherwise specified. Accurate measurement follows potentiometric RFE 2.2.3; strips are limited to checks not requiring high accuracy.
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], [6], [12]
Additional tests from the referenced SOP:
Appearance and mass/volume. For batches: colour, clarity/opalescence, relative density, pH and microbiological testing RFE 5.1.4.
pH under PN/CP/001: normally test the untreated sample unless otherwise specified. Accurate measurement follows potentiometric RFE 2.2.3; strips are limited to checks not requiring high accuracy.
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], [6], [12]
Storage
Well-closed dropper bottle; <30 °C. [1]
Dispensing
Do not use with a perforated tympanic membrane; appropriate clinical assessment is required. [1]
Labelling
Acetic Acid Ear Drops AEMPS
Otic use only where sterility is not required
Quantity: ____ Batch: ____
Prepared: ____ Use by: ____
Patient / dose / frequency: ____
Storage: Well-closed dropper bottle; <30 °C.
Temperature for this batch BUD: ____ [1]
Otic use only where sterility is not required
Quantity: ____ Batch: ____
Prepared: ____ Use by: ____
Patient / dose / frequency: ____
Storage: Well-closed dropper bottle; <30 °C.
Temperature for this batch BUD: ____ [1]
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
- FN/2003/FMT/003 ÁCIDO ACÉTICO, GOTAS ÓTICAS DE2003PDF pp. 2master formula2026-09-10
- CDC/NIOSH — Pocket Guide to Chemical Hazards: Ethyl alcoholΔιαθέσιμο κείμενο / Retrieved textOfficial referenceraw material or occupational2026-09-10
- FN/2003/PA/001 ACÉTICO GLACIAL, ÁCIDOΔιαθέσιμο 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
- PN/L/FF/007/00 ELABORACIÓN DE SOLUCIONESΔιαθέσιμο κείμενο / Retrieved textPDF pp. 1–6preparation sop2026-09-10
- PN/L/CP/001/00 DETERMINACIÓN DE PHΔιαθέσιμο κείμενο / Retrieved textPDF pp. 1–5qc method2026-09-10
- 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> FAQs (official, updated 1 November 2023)Updated 1 November 2023; retrieved 14 October 2026Q52, Q61–64; use with the applicable full chapterWater-activity classification, component dating and BUD documentation; general professional framework, not a Greek legal adoption or formula-specific study2026-10-14