FOR PHARMACISTS · SCIENTIFIC COLLECTION 10.0310 monographs · 36 SOPs · 22 forms

CGR-ES-018 / EDITION 10.0

Preserved Water EX001

Liquid base or auxiliary solution · Spain · AEMPS

2026-10-14Reference monograph · Local adoption

REFERENCE FORMULA

Reference formula

Reference basis: 100 mL

IngredientSource quantityScaled quantity
Hydroxybenzoate concentrate EX0251 g—
Purified waterq.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.

Scaling

Prerequisite formulations

Documentation

Preparation description
Clear, colourless solution. [1]
Action and use
Compounding base or auxiliary vehicle as named; addition of an active requires separate compatibility/stability assessment. [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
Component of base CGR-ES-017: Propylene Glycol: JP classifies the corresponding pure raw material as miscible in water.
Component of base CGR-ES-017: Methyl Parahydroxybenzoate: JP classifies the corresponding pure raw material as slightly soluble in water.
Component of base CGR-ES-017: Propyl Parahydroxybenzoate: JP classifies the corresponding pure raw material as very slightly soluble in water. [8], [9], [10], [11]
Humidity
Component of base CGR-ES-017: Propylene glycol is hygroscopic; close its container promptly after measuring.
Component of base CGR-ES-017: Propylene Glycol: the raw material is hygroscopic according to JP. [7], [8], [9]
Temperature
For the finished product the source specifies:
Well-closed amber 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
No complete compatibility test with added actives or alternative excipients is provided. Substitutions require separate evidence. [1]
Ingredient-specific information
Identity and weighing basis:
• Hydroxybenzoate concentrate EX025: 1 g.
• Purified water: q.s. ad 100 mL.
The specified chemical forms/grades belong to the exact source formula.
Component of base CGR-ES-017: Propylene glycol (1,2-propanediol): colourless viscous water-miscible cosolvent and humectant. A small amount does not establish adequate preservation.
Component of base CGR-ES-017: Propylene Glycol: raw-material water solubility is classified as miscible by JP.
Component of base CGR-ES-017: Methyl Parahydroxybenzoate: raw-material water solubility is classified as slightly soluble by JP.
Component of base CGR-ES-017: Propyl Parahydroxybenzoate: raw-material water solubility is classified as very slightly soluble by JP. [1], [7], [8], [9], [10], [11]
Staff protection
Clean long-sleeved laboratory clothing, hair covering and gloves during handling; change gloves after contamination or damage. [1], [2], [5]
Risk assessment
Component of base CGR-ES-017: Propylene glycol: assess exposure from all medicines, especially in neonates, children under 5 and renal/hepatic impairment. For oral dosing: mg/kg/day = mg/mL × daily mL ÷ body weight in kg.
Reference batch: 100 mL. First ingredient: Hydroxybenzoate concentrate EX025, 1 g. Independently check chemical form, units and every scale conversion before weighing.
As an intermediate, label identity and strength clearly and do not dispense as a finished medicine. Dilution or addition of an active requires new excipient, preservation and BUD calculations. Confirm release of every required base.
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.
For this procedure’s heating stage, check thermometer, heating method, duration and prevention of overheating/solvent loss. Completion of mixing does not establish cooling or complete homogenisation.
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], [7], [8], [13], [15]
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], [3]
BUD rationale
Period reported by source: 6 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], [6], [12], [14], [16]
Prerequisites
Hydroxybenzoate Concentrate EX025: CGR-ES-017 [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
Heat most water to 50 °C, add concentrate and mix; cool and make up volume. [1]
Observations
The 1 g is EX025 concentrate, not pure parabens or EX028. [1]
Container and packaging
Well-closed amber 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], [3], [4], [15]
Storage
Well-closed amber bottle; <30 °C. [1]
Dispensing
Intermediate base for compounding. Adding an active requires reassessment of the final composition, pH, preservation and BUD. [1]
Labelling
Preserved Water EX001
Compounding base — not for direct administration
Quantity: ____ Batch: ____
Prepared: ____ Use by: ____
Patient / dose / frequency: ____
Storage: Well-closed amber 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

  1. FN/2003/EX/001 AGUA CONSERVANTE2003PDF pp. 2master formula2026-09-10
  2. PN/L/PG/002/00 INDUMENTARIAΔιαθέσιμο κείμενο / Retrieved textPDF pp. 1–5general staff protection2026-09-10
  3. PN/L/FF/007/00 ELABORACIÓN DE SOLUCIONESΔιαθέσιμο κείμενο / Retrieved textPDF pp. 1–6preparation sop2026-09-10
  4. PN/L/CP/001/00 DETERMINACIÓN DE PHΔιαθέσιμο κείμενο / Retrieved textPDF pp. 1–5qc method2026-09-10
  5. ASHP — USP <795> Key Changes2023pp. 1–3: scope, water activity and staff precautionsprofessional guidance; not the licensed USP chapter2026-09-12
  6. 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
  7. EMA — Questions and answers on propylene glycol used as an excipient, EMA/CHMP/704195/20139 October 2017Sections 1–3 and annexingredient facts2026-09-12
  8. FN/2003/EX/025 SOLUCIÓN CONCENTRADA DE HIDROXIBENZOATOS2003PDF pp. 2master formula2026-09-10
  9. MHLW — Japanese Pharmacopoeia XVIII: Propylene GlycolJP XVIII, 2021; English textPrinted p. 1600; Description; Containers and storageraw-material monograph2026-09-12
  10. MHLW — Japanese Pharmacopoeia XVIII: Methyl ParahydroxybenzoateJP XVIII, 2021; English textPrinted p. 1343; Description; Containers and storageraw-material monograph2026-09-12
  11. MHLW — Japanese Pharmacopoeia XVIII: Propyl ParahydroxybenzoateJP XVIII, 2021; English textPrinted p. 1601; Description; Containers and storageraw-material monograph2026-09-12
  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
  13. 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
  14. 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
  15. 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
  16. 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