Photostability

The ICH Harmonized Tripartite Guideline on Stability Testing of New Drug Substances and Products is an internationally recognized document referencing the need for stability testing.

es2000_reach_in_photostability_chamber_brochure.jpgThe U.S. FDA has adopted the annex document Q1B, which states that products should be evaluated to demonstrate that light exposure does not result in unacceptable changes. Should changes occur, the drug manufacturer may reformulate or repackage the product to prevent further photo degradation.

In order to comply with the Q1B guideline of 11/96, the drug manufactureris required to use one of two optional light sources (paraphrased):

Option 1: A light source designed to produce an output similar to the D65/ID65 emission standard referenced to ISO 10977. Such sources include full spectrum fluorescent lamps, xenon or metal halide lamps. We offer a custom-made full spectrum fluorescent lamp which combines visible and ultraviolet-A outputs.

Option 2: Light sources designed to expose both cool white and near-ultraviolet light. These include:

  • A cool white fluorescent lamp to produce an output similar to that specified in ISO 10977. BES offers a custom-made cool white lamp to specifically replicate this standard.
  • A near-ultraviolet lamp with a spectral distribution from 320–400 nm. with maximum emission between 350 – 370nm. Significant portions of UVshould fall in the bands of 320 – 360 nm. and 360-400 nm. BES also offers a custom-made ultraviolet-A lamp to meet these specific emission guidelines.

Conditioning System

Our precise air control system ensures conditioned air is distributed uniformly across your product shelves. A stainless steel impeller moves the air through the conditioning components within the enclosed plenum.

Air is then distributed and returned through the plenum’s side wall portswhich are specifically arranged for maximum uniformity and efficientthermal transfer. The conditioning system features include:

  • Temperature control to within ±0.2°C
  • Relative humidity control to within ±0.7% RH
  • Temperature uniformity of ±2.0°C
  • Relative humidity uniformity of ±5.0%

Cabinet Construction

Our double-wall chamber construction provides you with years of continued, trouble-free use. The interior is heliarc-welded at the seams to form a hermetic seal which prevents moisture from migrating into the insulation.

Each chamber size is proportioned to allow you ease of passage through a standard doorway. Construction features and options include:

  • Heavy-gauge stainless steel interior with scratch-resistant enamel on exterior of cabinet.
  • Closed-cell urethane insulation for superior high/low temperaturestability and minimal heat transfer. The door is also completely foamedfor thermal performance and rigidity.
  • Heavy-duty door hinges, full peripheral magnetic door gaskets andpositive action latch with a lock to maintain a secure, uniform seal.
  • Removable stainless steel plenum cover and wall air chases forease in cleaning and maintenance.
  • Heavy-duty 2?casters (on floor models) and adjustable levelingfeet for ease in installation.
  • Highly reflective specular metal wall coverings on all vertical surfaces.

Proportional Refrigeration System

BES incorporates a proportional liquid/hot gas refrigeration design to maintain close tolerance temperature control and rapid acceleration to your setpoint. The compressor life is extended by modulating refrigerant flow as required. All facets help maintain the life of your chamber under photostability conditions. The proportional refrigeration system features are as follows:

  • Air-cooled, hermetically sealed compressor with environmentally safe, non-toxic, CFC-free refrigerants. Optional water-cooled units are available.
  • Expansion valve refrigeration control provides higher heat removal capacity than conventional capillary tube designs and provides immediate response to added heat loads.

Lighting System

BES’ upright floor models provide up to (3) simultaneous light studies with adjustable, uniformly-controlled light levels across your product shelves. Intensities are easily and individually controlled at each light bank with a microprocessor-based controller and a photo diode sensor to provide a fully automated, closed-loop control system. The features of each light bank are as follows:

  • Automatic adjustment of lamp output to maintain intensities at varied conditions.
  • Interchangeable cool white, near-ultraviolet, full spectrum, and dual source cool white/UV banks designed to meet Options 1 and 2 of current ICH/FDA guidelines. Three banks are accommodated in the upright floor model; one bank is provided in the benchtop model.
  • Independent light level and timing controls are provided at each individual light bank. Light bank timers provide precise testing durations.
  • Individual front reflector panels allow the chamber’s door to open without disturbing tests at other light shelves (floor model only).
  • Highly transparent light barrier for maximum transmission of visible and near-ultraviolet light while providing protection for the bulbs.
  • Stainless steel light bank shell with specular aluminum interior for corrosion resistance and high reflectivity.
  • Shelf-mounted telescoping sensor capable of accurate measurement and control of light levels through varied temperatures, product heights and reflective conditions. Each light surface has a controlling sensor.
  • Precision, silicon photo diode light sensor custom-designed by ES and factory calibrated per NIST traceable standards.
  • Light level setpoint configuration in kilolux or watts per sq. m. with a digital light level display. Optional units available on request.
  • High frequency electronic dimming ballasts offer up to 20% more efficiency than traditional electromagnetic ballasts.

We provide high intensity, uniform light levels through the use of optimum bulb positioning, highly reflective materials, and high output biax lamps. Extensive R&D has led to the unique bulb layout suitable for uniform exposure in 7-lamp, 4-lamp and dual source operation. Special high-grade specular aluminum covers all vertical surfaces and provides  ultimate reflectivity, resulting in excellent uniformity and higher light levels. The biax lamp design allows for 40 watt T-5 lamps to fit into a system normally capable of holding only 15–20 watt T-8 lamps. This means higher light levels and output per area than competitive light chambers. A popular feature of our lighting system is the dual source light bank. This is standard on the benchtop model and available as an option on the upright floor model. Both cool white and ultraviolet-A lamps are integrated into one single bank and independently controlled by a corresponding light sensor for a total of two light systems at each shelf (shown above). Each source may be operated independently or simultaneously with light uniformity within ±10% in the standard 70% marked region (shown above).

Alarm/Monitoring System

Our control panel features standard high/low visual and audible alarms for temperature, humidity and lighting. The alarms offer you instant visual indication and time-delayed audible indication for quick notification. The temperature and humidity alarms automatically shutdown specific mechanical equipment. The alarm monitoring system features include:

  • Alarm silence function on all parameters with up to 60 minutes of delay time (individually adjusted for each parameter).
  • Standard N. O./N. C. dry alarm contacts for remote monitoring of each parameter. There is one temperature, one humidity and one general lighting alarm.

Temperature Control System

Our user-friendly microprocessor-based control system incorporates a P.I.D. controller with a subpanel-mounted process board. This board features an L.C.D. backlit display and 4-function membrane switchpad. The system includes digital setpoint and process display of your controlled parameters, while indicator lights monitor power and alarm functions. A non-volatile memory retains your setpoints for restart in the event of a power failure. All controls are mounted on a hinged access panel for ease of maintenance. Features include:

  • Temperature display configuration in °C or °F.
  • Precision, platinum RTD temperature sensor calibrated per NIST traceable standards.

Upright floor model control panel shown with temperature and humidity control and optional three dual source light bank controls (6 total light systems)

Benchtop model control panel shown with temperature and humidity control,standard dual source light bank controls (2 total light systems) and optional strip chart recorder

Humidity Control System

Our solid-state controlled electric steam humidifier maintains close tolerance humidity control. The humidity system features a direct-set microprocessor control with digital setpoint and process display for your ease of use and readability. High/low humidity capability is dependent on your model selection. See the Humidity Performance Curve sheet for specific ranges on each model. The humidity system includes:

  • High output vapor generator with float switch actuated solenoid fill system.
  • Dual refrigeration coil design for dehumidification at temperatures depicted on the Humidity Performance Curve sheet.
  • Humidity display configuration in % RH.
  • Solid-state variable capacitance humidity sensor calibrated per NIST traceable standards.