Reference basis: Σταθερές φορτίσεις: 5 g + 50 mL + 50 mL· μετρούμενη τελική απόδοση / Fixed charges: 5 g + 50 mL + 50 mL; measured final yield
Ingredient
Source quantity
Scaled quantity
Tannic acid
5 g
—
Ethanol 96%
50 mL
—
Glycerol
50 mL
—
Prerequisite formulations
No separate prerequisite monograph is listed.
Documentation
Preparation description
Clear yellowish-to-amber tannic acid solution in ethanol and glycerol. The batch is defined by three charges; adding 50 and 50 mL does not establish a final 100 mL volume after mixing and dissolution. [1], [2]
Action and use
The source describes astringent/antiseptic use on intact skin and a historical pressure-ulcer prevention use, with 2–4 applications daily. This is not presented as a currently proven pressure-injury prevention protocol and does not replace clinical assessment or pressure-relieving care. [1], [2]
Specifications
Use tannic acid RFE 1477, ethanol 96% RFE 1317 and glycerol RFE 0496. Finished appearance: clear yellowish-amber solution. No finished assay or pH range is given. A percentage-strength claim requires a documented final volume. [1], [2], [3]
Light
The master requires an amber bottle and protection from light. Investigate colour change or precipitate as a deviation; colour is not a quantitative potency assay. [1], [6]
Air and oxidation
Close tightly after preparation and each use to limit loss of the volatile alcoholic solvent and composition changes. No evaporation rate or repeated-opening study is supplied. [1], [4]
Water and solubility
No separate water charge is listed, but ethanol 96% contains water and hygroscopic materials can take up moisture. Do not add water to make an assumed 100 mL volume; that changes the published formula. No aw measurement is available. [1], [3], [4], [5], [7]
Humidity
Glycerol is hygroscopic. Keep its container closed, minimise open measuring time and apply the general procedure environment of relative humidity ≤60%. Ambient humidity is not a substitute for a BUD assessment. [3], [5], [6]
Temperature
Prepare without heating: ethanol is volatile and flammable. The master gives no numerical storage temperature; local adoption should specify controlled room temperature 20–25 °C away from heat as an added restriction, not a published stability-study condition. [1], [4], [6]
pH and compatibility
No final pH or buffer system is specified. An aqueous pH method cannot simply be transferred to this alcoholic–glycerol mixture; any local pH test needs a defined method. Do not add pH adjusters. [1], [2], [6]
Other interactions
Tannic acid is incompatible with metal salts, particularly iron salts, and with alkaloids, proteins/gelatin and limewater. Keep glycerol and ethanol separate from strong oxidisers, especially potassium permanganate. [2], [3], [4], [5]
Ingredient-specific information
Tannic acid is a mixture of glucose esters of gallic and digallic acids rather than a single fixed-stoichiometry molecule. It dissolves in ethanol and glycerol; glycerol is the viscous vehicle. Do not substitute 50 g for the specified 50 mL of glycerol without a justified density calculation. [1], [2], [3]
Staff protection
Use solvent-compatible gloves, eye protection and a coat; contain tannic acid dust during weighing. Ventilate ethanol measuring operations and exclude flames/sparks. The flash point of neat ethanol is not represented as a measured flash point of this mixture. [2], [4], [5], [6]
Risk assessment
Avoid large, denuded or damaged surfaces and prolonged use: the source reports liver injury from systemic absorption. Local irritation is possible. Process risks include alcoholic-solvent ignition, replacing volume with mass, and claiming an unverified 5% w/v strength. [1], [2], [4]
Compounding conditions
Weigh 5 g tannic acid and separately measure 50 mL ethanol 96% and 50 mL glycerol. Use measuring equipment suitable for viscous liquids and quantitative transfer. There is no q.s. ad instruction; measure yield after mixing without arbitrary topping up. [1], [3], [6]
BUD rationale
The source states three months, tightly closed in amber glass and protected from light, without a numerical temperature or analytical stability study. With documented local adoption of the exact charges, yield checks and an added 20–25 °C restriction, the ceiling is the earliest of 89 days, three calendar months and ingredient limits. Ethanol presence does not establish a low-aw USP category or demonstrated preservative efficacy. 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], [7]
Prerequisites
No intermediate base is required. Dependencies are identified raw materials, accurate glycerol volume measurement, the solutions procedure and an approved label that does not assume a 100 mL final volume. [1], [6]
Equipment
Balance suitable for 5 g, calibrated volume measures for ethanol and glycerol, glass beaker, stirrer, compatible filter if needed and amber bottle. Keep equipment clean, dry and free of metal-salt contamination. [1], [2], [6]
Compounding method
1. Dissolve tannic acid in the 50 mL ethanol 96%. 2. Filter only if needed and assess any loss. 3. Add the 50 mL glycerol and mix thoroughly. 4. Measure actual yield and package. Do not add solvent to reach an assumed 100 mL. [1], [6]
Observations
The source code is retained, while this record title states the actual charges. Final w/v strength can be calculated from 5 g and recorded final volume only if active-material loss has been excluded. [1], [6]
Container and packaging
Amber bottle with tight closure compatible with the alcoholic–glycerol mixture. Select capacity after measuring actual volume; do not use food/drink containers. [1], [4], [6]
Quality control
Check inputs, final yield, clarity, colour and absence of precipitate. Particles after filtration require investigation for incompatibility. The general procedure identifies additional batch tests, but the master supplies no ready tannic acid assay method or numerical pH range. [1], [2], [6]
Storage
Keep tightly closed, protected from light and ignition sources. For the local adoption framework used here: 20–25 °C. Absence of precipitate does not substitute for chemical or microbiological stability evidence. [1], [4], [7]
Dispensing
Use only on intact skin with treatment area and duration specified by the clinician. Do not promote it as a general pressure-injury prevention product without clinical assessment. Avoid eyes/mucosa, extensive or prolonged application and swallowing. [1], [2]
Labelling
Tannic acid solution — reference charges 5 g tannic acid / 50 mL ethanol 96% / 50 mL glycerol. For intact skin only, as prescribed. Do not swallow. Protect from light/heat, keep tightly closed at 20–25 °C. Enter actual quantity, batch, 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 — ÁCIDO TÁNICO, SOLUCIÓN DE (FN/2003/PO/005)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 tánico (FN/2003/PA/036)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
AEMPS — Glicerol (FN/2003/PA/013)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 0044 — Ethanol (anhydrous)May 2018Identity; 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
ILO/WHO International Chemical Safety Card 0624 — GlycerolApril 2006Identity; 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
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
