Our Laboratory Testing Blog

In moving from a chemical to an instrument-based methodology, the USP has taken great care to allow for a flexible approach and is working closely with both the FDA and industry to ensure widespread agreement on interpretation of the revisions.  Following are brief descriptions of the techniques and methodologies being proposed by USP:

The analysis of low abundant signaling molecules such as phytohormones such as jasmonic acid (JA), salicylic acid (SA) and abscisic acid (ABA) and intermediates of metabolic pathways such as free fatty acids (FFA) and oxygenated forms of fatty acids in plants is an important tool to understand how plants grow, develop and respond to stress conditions.  Therefore, it is essential to develop quantitative analytical testing methods for the rapid, simultaneous and reliable analysis of a broad range of plant molecules.

First introduced over 100 years ago, USP<231> is a colorimetric procedure based on the precipitation of insoluble metal sulfides.  This test is qualitative rather than quantitative.  It is not an element specific method, nor is it equally sensitive to each metal.  The limits specified by the test are based on the ability to observe the precipitate, rather than on the analysis of toxicological data.  The procedure does not necessarily detect all potential forms and/or valences of elements of concern when they are present as the oxo ions or in the organometallic form.  Chromium and nickel are potential contaminants from modern stainless steel processing equipment and are not detected by USP<231>.  Other studies indicate inconsistent recoveries of monitor and standard solutions using USP<231> method II.2, 3

Here at Diteba, we field many inquiries about stability storage and testing for many different dosage forms.  These inquiries are usually varied and often very general.  The questions can range from what stability storage and testing services we can offer to general information questions about what shelf life testing is or how to go about conducting one of these studies.

Throughout 2011, we have been talking to customers about what their testing needs are, what has worked for them, what hasn't worked in 2011 and strategizing about how this will impact their laboratory testing plans for 2012.  This includes reviewing our blog to make sure we understand which articles had resonated the most with our website visitors.

Capillary Electrophoresis (CE) is a relatively new analytical technique for the separation and analysis of small and large molecules such as peptides and is complementary to existing approaches such as High Performance Liquid Chromatography (HPLC).  The advantages of CE over HPLC include:

Drugs have been administered nasally for therapeutic and recreational purposes since ancient times.  Psychotropic drugs and hallucinogens were snuffed for these purposes by the South American Indians, and this practice is currently widespread among abusers of cocaine and heroin.

Although FDA does not officially require it yet, the human cadaver skin model is a powerful and sensitive tool by which to accurately quantitate a semisold drug’s rate of percutaneous absorption.  This has application within multiple areas of the semisolid drug development process.  The area of greatest application historically has been in preclinical development, where it is used to screen and select the optimum formulation for further development.

A performance test for topical drug products must have the ability to measure drug release from the finished dosage form.  It must be reproducible and reliable, and although it is not a measure of bioavailability, the performance test must be capable of detecting changes in drug release characteristics from the finished product.

Pancreatic enzymes are essential for hydrolytic intraluminal breakdown of macronutrients into smaller, absorbable metabolites.  Porcine pancreatic extract is used to treat pancreatic enzyme deficiency.  It is often prescribed for people with cystic fibrosis, chronic inflammation of the pancreas, or blockages of the pancreas or common bile duct caused by cancer.  It is also taken by people who have had their pancreas removed or who have had gastrointestinal bypass surgery.  Pancrease is taken to help with digestion of proteins, starches, and fats.