SPREADMASTER Automated Sample Spreading Instrument for In Vitro SPF Testing

Overview

The SPREADMASTER Automated Sample Spreading Instrument is a precision-engineered platform developed by HelioScreen (France) and distributed globally by Wenoes for standardized in vitro SPF (Sun Protection Factor) testing of sunscreen formulations. It operates on the principle of controlled, motorized blade-based deposition to deliver reproducible, uniform film thicknesses of sunscreen products onto standardized test substrates—specifically the HD6 quartz slide template and the SB6 sandblasted polycarbonate template. This instrument directly addresses a critical source of variability in ISO 24443:2021 and COLIPA/ISO-compliant in vitro SPF protocols: manual application inconsistency. By eliminating operator-dependent spreading parameters—including pressure, speed, angle, and dwell time—the SPREADMASTER ensures traceable, auditable, and GLP-aligned sample preparation, forming the foundational step for reliable UV absorbance quantification via spectrophotometric analysis.

Key Features

• Programmable spreading parameters: adjustable blade speed (0.5–5 mm/s), contact force (0.1–2.0 N), and dwell time (0–5 s) via intuitive touchscreen interface
• Dual-template compatibility: dedicated fixtures and calibration routines for both HD6 (high-transmission quartz) and SB6 (micro-roughened polycarbonate) substrates per ISO 24443 Annex A
• Integrated environmental monitoring: real-time logging of ambient temperature (±0.2 °C) and relative humidity (±2% RH) during operation
• Non-contact film thickness verification: optional integration with optical profilometry modules for post-spread validation (compatible with Wyko, Zygo, or Keyence systems)
• Modular design: tool-free substrate holder exchange; stainless-steel fluid path components resistant to organic solvents and emulsion residues
• Compliance-ready architecture: built-in audit trail generation, user access levels (admin/operator), and timestamped event logs aligned with FDA 21 CFR Part 11 requirements

Sample Compatibility & Compliance

The SPREADMASTER accommodates a broad range of sunscreen formulations—including oil-in-water emulsions, water-in-oil emulsions, anhydrous gels, spray-on aerosols (with optional nebulizer adapter), and nanoparticle-containing suspensions—without clogging or blade smearing. All mechanical and software functions adhere to the procedural constraints defined in ISO 24443:2021, ASTM D7566-22 (Standard Practice for In Vitro SPF Determination), and the European Cosmetics Regulation (EC No 1223/2009) Annex VI. Substrate positioning accuracy is validated to ±5 µm across the full 22 × 22 mm HD6 surface, ensuring consistent UV beam illumination during subsequent spectrophotometric scanning. Instrument qualification documentation (IQ/OQ/PQ templates) and metrological traceability certificates (NIST-traceable force and displacement calibrations) are supplied with each unit.

Software & Data Management

The embedded firmware (v3.2+) supports dual-language UI (English/French) and exports structured CSV and XML datasets compliant with LIMS integration standards (ASTM E1482, HL7). Each spreading run generates a unique digital record containing: substrate ID, formulation lot number, operator ID, environmental conditions, parameter set version, and raw motion profile data (position vs. time). Optional cloud synchronization enables centralized method library management across multi-site laboratories. All data files include SHA-256 checksums and are write-protected after completion to satisfy ALCOA+ principles (Attributable, Legible, Contemporaneous, Original, Accurate, Complete, Consistent, Enduring, Available).

Applications

• Routine in vitro SPF screening during sunscreen formulation development and stability testing
• Regulatory submission support for EU CPNP, US FDA OTC Monograph, and ASEAN Cosmetic Directive dossiers
• Method transfer between contract research organizations (CROs) and internal R&D labs
• Inter-laboratory comparison studies under ISO/IEC 17043 proficiency testing schemes
• Root cause analysis of SPF outliers through retrospective review of spreading parameter deviations
• Validation of alternative substrates (e.g., synthetic stratum corneum membranes) per emerging OECD TG 439 extensions

FAQ

Does the SPREADMASTER require daily calibration?
No—mechanical calibration is performed annually using certified reference artifacts; however, daily verification with a standard reference slide (provided) is recommended before first-run use.
Can it be integrated with existing UV-Vis spectrophotometers?
Yes—substrate carriers are dimensionally compatible with Agilent Cary 60, PerkinElmer Lambda 950, and Shimadzu UV-2600 systems; custom mounting adapters available upon request.
Is training included with purchase?
Yes—Wenoes provides on-site installation, SOP development support, and two-day operator certification training accredited by the European Society for Photobiology (ESP).
What maintenance intervals are specified?
Blade replacement every 500 runs; linear guide lubrication every 6 months; full system diagnostic check annually per ISO 17025 clause 6.4.4.
Does it support 21 CFR Part 11 electronic signatures?
Yes—role-based e-signature capability is enabled via PKI certificate integration and requires external identity provider (e.g., Microsoft Azure AD or Okta) configuration.