Boric acid 3% w/v aqueous cutaneous solution · CGR-ES-091 (CGR-ES-091)

REFERENCE FORMULA

Reference formula

Reference basis: 100 mL / 100 mL

Ingredient	Source quantity	Scaled quantity
Boric acid	3 g	—
Purified water	q.s. ad 100 mL	—

Prerequisite formulations

No separate prerequisite monograph is listed.

Documentation

Preparation description

Clear colourless solution containing 3 g boric acid in a final 100 mL, equivalent to 30 mg/mL. No separate preservative or buffer is listed. Heating during preparation does not make it sterile. ^{[1], [2]}

Action and use

The source lists a weak cutaneous antiseptic action with twice-daily application. Restrict use to a limited area of intact skin for a clinical indication; not for eyes, mouth, nose, mucosa or wounds. ^{[1], [2]}

Specifications

Use boric acid RFE 0001 and purified water RFE 0008. The raw-material assay of 99.0–100.5% is not a finished-solution limit. Check clarity, absence of crystals and final 100 mL volume; no final pH or assay acceptance range is supplied. ^{[1], [2], [5]}

Light

Store in an amber bottle, protected from light. This requirement is supplied without a quantitative photodegradation study. ^[1]

Air and oxidation

Keep the bottle tightly closed to limit water evaporation, concentration increase and contamination. The source does not require inert-gas blanketing. ^{[1], [5]}

Water and solubility

Water is the main vehicle. Use purified water, not tap water, and make up final volume only after cooling. Weak boric acid antiseptic activity does not establish effective preservation of the container contents. ^{[1], [2], [6]}

Humidity

Control raw-material dust in a clean dry weighing station. The general procedure specifies relative humidity ≤60%. No separate humidity-sensitivity specification is given for the finished aqueous solution. ^{[3], [5]}

Temperature

Bring water to boiling for dissolution and cool before filtration/final volume adjustment. Store below 25 °C. ICSC reports water solubility of 5.6 g/100 mL at 20 °C, not at 2–8 °C; it does not establish compatibility of refrigerating a 3% solution. ^{[1], [3]}

pH and compatibility

Boric acid is a weak acid. This formula has no specified final pH or acceptance range. Values for other concentrations in toxicological literature are not finished-product specifications. Do not add alkali to adjust pH. ^{[1], [3], [4]}

Other interactions

Avoid mixing with alkalis, carbonates/hydroxides, polyvinyl alcohol or tannins, which the official raw-material monograph lists as incompatibilities. Do not add a colourant without an approved revised formula, although the master mentions optional colouring. ^{[1], [2], [3]}

Ingredient-specific information

Boric acid H3BO3, CAS 10043-35-3, molecular mass 61.8. The 3 g charge is boric acid, not elemental boron; borax is not a substitute. Hot water facilitates dissolution, but final clarity must be checked after cooling. ^{[1], [2], [3]}

Staff protection

Contain dust/use local extraction when weighing; wear gloves, coat and eye protection. Add burn controls for boiling-water transfer. The raw material is classified as potentially damaging fertility and the unborn child; occupational assessment must address inhalation and reproductive exposure. ^{[3], [4], [5]}

Risk assessment

The source excludes children under 3, large surfaces, mucosa, wounds/burns and prolonged use. Absorption through intact skin is low but increases with barrier damage; children and renal impairment require particular assessment. Systemic exposure can cause gastrointestinal, neurological and renal toxicity. Reproductive-toxicology data do not by themselves establish a safe topical dose. ^{[1], [3], [4]}

Compounding conditions

For 100 mL weigh 3.00 g. After heating/dissolving, cool fully before setting final volume. Use clean equipment and controlled-quality water; neither boiling nor simple filtration is validated sterilisation. ^{[1], [5]}

BUD rationale

AEMPS states three months, tightly closed in amber glass, protected from light below 25 °C. No full exact-formula stability study, challenge test or in-use data were identified. The 89-day value is only the source-specific ceiling after documented local adoption with microbiological-quality controls, further limited by three calendar months and ingredient expiry. It is not a USP default. Where only the general unpreserved aqueous rule is used, 14 days requires 2–8 °C and prior evidence against crystallisation; it cannot become 14 days at room temperature. Without source-specific adoption or refrigeration compatibility, do not release with an arbitrary BUD.

Initial microbiological testing alone does not establish suitable quality for 89 days. Local adoption of the period must address microbiological quality throughout dating, the multidose bottle and handling after opening. Editorial convention: calendar-month source periods are retained as calendar periods; the calendar-period conversion ceiling is 28 days for one month or 89 days for three months; a separately selected shorter ceiling still governs. It is a conservative conversion, not a source quotation. ^{[1], [3], [6]}

Prerequisites

No intermediate solution is needed. Required dependencies are boric acid/water specifications, the solutions procedure and a documented source-specific BUD assignment pathway. The cutaneous label must prominently prohibit swallowing. ^{[1], [2], [5], [6]}

Equipment

Balance suitable for 3 g, heat-resistant glass beaker, electric hotplate, stirrer, suitable filter, 100 mL volume measure and amber bottle. Provide protection for handling hot equipment. ^{[1], [5]}

Compounding method

1. Heat a portion of purified water to boiling. 2. Dissolve all boric acid. 3. Allow to cool. 4. Filter and make up to exactly 100 mL with purified water. 5. Confirm clarity at storage temperature, transfer to the bottle and close. ^{[1], [5]}

Observations

The name boric water does not mean an ophthalmic preparation. This formula/process is nonsterile and does not automatically meet isotonicity or ophthalmic requirements. Crystals after cooling are a deviation, not a reason to relabel the solution as a shake-before-use suspension. ^{[1], [2], [5]}

Container and packaging

Tightly closed amber bottle suitable for an aqueous cutaneous solution. Use packaging unlikely to be mistaken for drinking water or eye drops, in a practical quantity matched to the authorised treatment. ^{[1], [5]}

Quality control

Check material identity, weight, final volume after cooling, clarity and crystals. For batches, the general procedure includes pH/density and microbiological checks where applicable; local methods/limits are needed and were not performed here. Visual clarity does not establish microbiological safety. ^{[1], [5]}

Storage

Store below 25 °C, protected from light and tightly closed. Do not introduce applicators or contaminated material into the bottle. Do not change to refrigerated storage without evidence of physical compatibility at this concentration. ^{[1], [3], [6]}

Dispensing

Confirm age ≥3 years, intact skin, limited treatment area and a short authorised course. Assess pregnancy/lactation and renal disease. Ingestion or systemic symptoms require immediate medical/poison-centre advice; do not give self-treatment instructions for poisoning. ^{[1], [4]}

Labelling

Boric acid 3% w/v (30 mg/mL) — cutaneous use only. DO NOT SWALLOW. Not for eyes, mucosa, wounds or children under 3. Use as prescribed. Store below 25 °C, protected from light, tightly closed. Enter batch, quantity, preparation and authorised use-by dates during execution. ^{[1], [4]}

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.

Sources and references

AEMPS, Formulario Nacional — AGUA BORICADA (FN/2003/PO/006)FN/2003 source identifier; current standalone official PDF accessed 2026-10-13PDF pp. 2–3; composition, specific method, storage, validity and patient leafletMaster composition, preparation and source-specific conditions. Independently written factual adaptation; not an official translation or endorsement. No laboratory testing performed for this document.2026-10-14
AEMPS — Ácido bórico (FN/2003/PA/007)FN/2003; standalone official PDF accessed 2026-10-13PDF p. 2Raw-material identity, physical properties, incompatibilities and route-specific precautions; raw-material assay limits are not finished-product specifications.2026-10-13
ILO/WHO International Chemical Safety Card 0991 — Boric acidApril 2014Identity; hazards/prevention; physical properties; chemical dangers; notesOccupational hazards of the identified raw material. Neat-material flash points and toxicity are not measured finished-mixture properties.2026-10-13
EMA — Boric acid and borate used as excipients: supporting report, Rev. 1EMA/CHMP/765436/2012 Rev.1, 11 November 2021; published 28 July 2022Summary; pharmacokinetics and dermal absorption; developmental/reproductive toxicity; pp. 3–6 and safety discussionBoron toxicology and exposure assessment. Excipient guidance does not itself establish an active topical product dose, BUD or an efficacy claim.2026-10-13
AEMPS — Elaboración de soluciones (PN/L/FF/007/00)Official FN procedure, version 00, accessed 2026-10-13Sections 5–6: environment, preparation, packaging, finished-product checksOfficial general dosage-form procedure; exact formula method takes precedence; batch-level tests are distinct from tests actually performed.2026-10-13
USP — Compounding Standards and Beyond-Use DatesNovember 2022 update, official USP fact sheet hosted by Mississippi Board of PharmacyNonsterile preparation BUD overview and category tableGeneral BUD framework; an AEMPS source period is not automatically a USP–NF monograph exception, and no measured water activity is implied.2026-10-13
USP — General Chapter <795> Frequently Asked QuestionsNovember 1, 2023 FAQ; rechecked 14 October 2026Questions 52, 54–56, 61, 64–66General category/extension rules only; not exact-product stability evidence.2026-10-14