A Primer on Drug Stability Testing in Stability Chambers

As described by the FDA, stability testing provides evidence of the effect of time and environmental factors on the quality of pharmaceuticals and medicinal products.  Such factors include light, humidity and temperature.  Stability tests also establish a re-test period for the drug substance or a shelf life for the medicinal product along with recommended storage conditions.

Stability tests are conducted in validated stability chambers such as manufactured by Norlake for pharmaceutical (ICH), biological (BOD), scientific and laboratory applications. These tests, which subject the product samples to variations in temperature and humidity, are conducted during drug product development as well as once a candidate drug reaches use and are governed by current good manufacturing practices (cGMPs). They are regulated in the U.S. by 21 CFR Part 211 Section 166. (www.gmp1st.com/drreg.htm#211.166)

While these tests are conducted in stability test chambers, it is not simply a matter of buying a chamber and plugging … Read the rest

A Primer on Precision Scale Calibration and Test Weights

Precision digital scales and analytical balances must be recalibrated for accuracy to be in compliance with international standards and to maintain good laboratory practices.  Analytical balances such as the Kern ABJ series can be recalibrated using internal motor-driven weights.  The internal calibration sequence is initiated manually.  Semi-micro analytical balances such as the Kern ABT series automatically recalibrate using internal weights under four scenarios:  1) Four hours after the previous calibration; 2) When there is a fluctuation in temperature of 0.5oC (0.9oF); 3) When the balance is switched from standby to weighing mode and condition (1) or (2) has been met or 4) If the balance was disconnected from its power source.

Other scales require external recalibration, which is performed by using test weights under procedures that should be spelled out in your company’s Quality Management manual.… Read the rest

Pipette Calibration Made Easy

Poorly calibrated pipettes impact accuracy and reproducibility.  As with precision laboratory scales and balances, periodic recalibration is necessary for testing and adjusting pipettes in accordance with ISO 9001 and GLP directives.

Recalibrating pipettes in-house is made easy with the aptly named EASYCAL™ 4.0 test software on CD-ROM available through Tovatech.  It guides technicians through the PC-based pipette test procedure, carrying out all calculations automatically and comparing them with the tolerance of the current norms or previously defined custom limit values.… Read the rest

How to Use an Ultrasonic Clock Cleaner

Another  interesting note from a customer:

“Don’t knock my smock or I’ll clean your clock” was a panel line in a Calvin and Hobbes cartoon strip. As one who repairs antique clocks I checked the origin of the phrase and found that it usually signifies a violent encounter. Not a good idea when dealing with a customer’s heirloom time keeper.

Most of the clocks I clean and repair have brass works – the gears and frames – along with steel parts such as verges, spindles, spacers and springs.  In my early days cleaning these parts after disassembly entailed dipping them into a solvent and using a soft brush to work away grime and dried lubricants.  A messy process indeed, and not that satisfactory in terms of results.

An ultrasonic cleaner has proven far more satisfactory, but when using this technology for clocks and watches care must be taken not to … Read the rest

Ultrasonic Cleaning Solution for Rust and Corrosion Protection

Here’s a note we got from a customer:

Years ago in my high school science lab we were taught that rust was a form of oxidation or corrosion, colorfully described as slow burning.  To demonstrate, the teacher put some fine steel wool to the Bunsen burner, and sure enough, she was right!

Fast forward to today when I operate a small metal casting and fabricating shop that produces parts generally made out of gray iron and mild steel.   Parts are degreased and loose burrs removed in my Elma S 120 ultrasonic cleaner, then stored for a short period of time before being painted.… Read the rest

Tips to Extend the Life of Ultrasonic Cleaning Solution

Ultrasonic cleaning is a proven method of removing dirt, contamination, paint, rust, tarnish – virtually any unwanted material that adheres to products being manufactured or repaired.  But dirt and contamination have to go somewhere and that “somewhere” is in the ultrasonic cleaner solution – or bath.  This simple fact brings up three points of concern for operators of ultrasonic cleaning facilities.… Read the rest

Ultrasonic Gun Cleaner for Both Ancient & Modern Firearms

When I was a kid I developed an interest in firearms and target shooting. After target practice using a nearby cliff as a backstop it was time to clean and lubricate my weapon for the next go-round.

Over the years my collection grew to include a vasriety of antique and collector pistols, many of which required repair and all requiring a thorough cleaning and lubricating.  When members in my shooting club discovered that I repaired weapons they asked if I could service theirs.  Each repair can take time, so I looked into a way of “automating” the cleaning and lubricating process.

A friend at the local state police barracks said they used an ultrasonic cleaner to clean and lubricate all of their weapons.  I looked into this and found the perfect solution in an HCS 200 ultrasonic cleaner offered by Tovatech. Attractively priced it is designed for the recreational shooter, hobbyist and collector. … Read the rest

Building an Ultrasonic Cleaning Business on a Bright Idea

Here’s an interesting letter we got from a customer:

Every holiday season my brother and I had the unenviable task of cleaning and polishing the “good” sliver in preparation for family gatherings around the festive board. Afterwards, no matter how carefully we wrapped the sterling flatware, candlesticks and napkin rings, they developed tarnish.  Dipping them in one of those silver cleaning solvents was not an option, so out came the Wright’s Silver Cream and the polishing cloths.

During a summer job as a lab assistant I was introduced to ultrasonic cleaning as a means to remove dirt and tarnish from lab equipment before sterilization.  Thinking back on my childhood holidays, I thought “why not?”  With permission from my boss I put a few pieces of flatware into the ultrasonic cleaner and, well, it accomplished in minutes what it my brother and I spent far too much time on.  The ultrasonic … Read the rest

How to Use a Precision Scale for Check Weighing

“Net weight one pound” it says on a bag of potato chips.  You used to be able to buy a pound of coffee but now while the cans look the same the weights vary.  One brand notes 11.5 ounces, another 10.3 ounces.  Why is this? More than that, how do we know the can really contains 10.3 ounces of java?  It is a conundrum we have to tolerate.

Joking aside, accuracy in weighing or in counting is no laughing matter when it comes to complying with rules governing net content and average weights.  It is also important from a cost management perspective. While variances in potato chip and coffee weight is not a serious safety concern, putting more in the bag or can than called for is a cost management issue.  Accuracy is a safety issue when it comes to pharmaceutical dosages and similar critical applications.  Here is how precision … Read the rest

How to Choose an Ultrasonic Cleaning Solution

Just as correct tools facilitate building, maintenance and repair, selecting the correct ultrasonic cleaning solution is important not only to ensure thorough cleaning but also to avoid damaging the items being cleaned in the ultrasonic equipment.

When discussing ultrasonic cleaner solutions with colleagues I refer to information provided by Elma, which manufactures ultrasonic cleaning equipment ranging from home healthcare units to heavy-duty industrial ultrasonic cleaning machines that are available through Tovatech.  Common to all these cleaning solution concentrates is their biodegradability – a far cry from trichloroethylene and similar harsher solvents used in the past.… Read the rest