Hello, this is Michael Peat and I'm going to talk to you about oral fluid laboratory drug testing. I'm going to give you a brief overview of what's involved in that testing from a program point of view, what some of the basic pharmacological implications are and what the drugs are and what their cut-offs are. Oral fluid drug testing has in fact been used for a number of years outside of the regulated arena, both in non-regulated workplace testing, in rehab testing, in pain management programs and in clinical testing for both toxicology and therapeutic drug monitoring. So there is nothing new or unusual about oral fluid drug testing. And as Dr. Smith has pointed out in one of her presentations, HHS has approved oral fluid testing and established protocols for collection, laboratory testing and medical review officer review. And DOT is preparing rules for its implementation into the regulated arena. That may take a few months, but obviously as all things do, this too will become part of the regulated DOT program. I'm going to cover the cut-offs that are in use and cover what the differences are and the similarities are to the urine drug testing program. There are more similarities than differences in this particular part of what will become a DOT regulated test. So I'm going to transition to the cut-off slide and that will take us into a discussion around cut-offs and what the differences are. My first slide includes the screening and confirmation cut-offs. The notable factor here compared to urine is the concentrations. They are much lower, orders of magnitude lower. But these concentrations are those that are necessary to detect the drugs of abuse in oral fluid. And they're confirmation cut-offs that are in common use in non-regulated testing today. The technology is here to detect these cut-offs quite freely and there's nothing complicated in any of that. However, marijuana use is detected by screening and confirming the psychoactive constituent THC and not the primary metabolite THC acid, which I talked about in my urine presentation. And I'll come to why that is in a few slides. In addition, cocaine has been added to the panel and the cocaine and benzolecanine cut-offs are 8 ng per ml for confirmation and 15 for screening. The rest of the drugs that are on this panel are the same that would be included in a urine panel. The opiates, codeine and morphine, the opioids, hydrocodone, hydromorphone, oxycodone, oxymorphone, 6-acetylmorphine, which is the primary metabolite of heroin and the initial metabolite on the way from heroin to morphine, fencyclidine, and amphetamine, methamphetamine, methylamphetamine and methylamphetamine. Compounds are routinely included in the urine screening program as well as an oral fluid screening program. So my next slide is going to cover some of the important points about this type of testing and some of the pharmacology of the testing. So we will move on to the next slide. This slide covers some important aspects of oral fluid laboratory testing. As I said earlier, the approach is identical to that of urine testing. It is an immunoassay test followed by a confirmation test using mass spectrometric procedures. The latter could include many different technologies, liquid chromatography, mass spectrometry, gas chromatography, mass spectrometry, liquid chromatography, mass spectrometry, mass spectrometry, etc. Again, there is nothing unusual about these technologies. They are routinely in use in drug testing labs and routinely in use in clinical chemistry and other clinical testing labs. The chain of custody and quality control protocols are similar, if not identical, to urine testing. Dr. Smith has gone through the collection process, which results in a chain of custody document and specimens being delivered to the laboratory. And I, in one of my other presentations, have gone through the laboratory testing process. One important characteristic of this testing is that no specimen validity testing is required by HHS and presumably DOT. That is because the testing or the collection is directly observed and therefore it will be very difficult to adulterate or dilute that type of observed collection. That's an important factor and obviously a benefit of oral fluid testing. THC is included in the protocols itself and not THC metabolite. I will cover that in a couple of slides because that is a very important difference in oral fluid testing compared to urine drug testing. To be certified for oral fluid testing, a lab is going to have to demonstrate competency through satisfactory performance testing and inspection. As I mentioned in my urine drug testing slides, the National Laboratory Certification Program is responsible for certifying the drug testing labs. In this part of that program, they will be responsible for providing performance testing to the labs so that the labs can demonstrate their competency through satisfactory analysis of performing testing specimens and then secondly through a satisfactory inspection. This is identical to what was used to certify labs for the opioids in 2018 and as most labs who do oral fluid testing also do urine drug testing, this will not be unusual to them. Ongoing certification will be identical. Satisfactory performance testing on specimens every three months and inspection every six months. So nothing unusual here in terms of this certification of the labs or the drug testing procedures. The differences are no specimen validity testing, the analysis of THC. My next two slides are going to cover properties of oral fluid and the transfer of drugs from blood or serum to oral fluid. This slide deals with the pharmacology of oral fluid and there's nothing new in particular about oral fluid drug testing as I said earlier. Oral fluid drug testing is based on parts of this slide and obviously a bigger discussion is the transfer of drugs from blood or serum into oral fluid which is on the next slide. So oral fluid is produced by three glands, parotid, submandibular and sublingual. There are two types of secretion, cirrus which is water containing electrolytes and amylase and mucus which contains mucins. Oral fluid flow is quite considerable per day between 0.5 and 1.5 liters per day and actually can be stimulated to 10 milliliters per minute. Some of the pads that are in use today actually stimulate oral fluid production during the collection process and this allows more oral fluid to be deposited in the pad than might be the case under normal circumstances if that pad did not stimulate the flow. Oral fluid also has a wide pH range 6.0 to 7.8 and this is important when we consider the transfer of drug from blood serum into oral fluid which is on the next slide. So let's talk about what's important in the transfer of drugs from blood serum into oral fluid. There are two factors that are most important. That is the pH of the oral fluid compared to plasma and related to that the pKa if you remember what that is of the drug or drug metabolite. The driving factor for non-ionized drugs to go into oral fluid is the pKa particularly for the weak basic drugs and the weak acidic drugs. Incorporated into the oral fluid panel are many weakly basic drugs such as amphetamines, PCP, 6-acetylmorphine, to some degree the opiates although there may be other factors that are important with opiates and opioids, and cocaine and benzolecanine. The other factor that's very important in this transfer is plasma protein binding and all drugs to some degree bind to the plasma proteins, some more efficiently than others. Within the panel tested THC and THC acid metabolite bind to greater than 90% to the plasma proteins and that is a factor in their transfer and that is a factor in their transfer from blood serum into oral fluid because truly only free non-protein bound and non-ionized drug can cross the membranes into oral fluid. So very little of the THC and THC acid that are present in plasma actually cross into oral fluid. Interestingly the buccal cavity which is highly lipid is a trap for drugs that are either smoked, inhaled or insufflated. Obviously if it's oral use little drug may be trapped in the buccal cavity but some can and in THC's case if a person eats a marijuana brownie or takes a THC therapy therapeutically very little if any THC is trapped in the buccal cavity for two different reasons. Obviously the capsules that are used in therapeutics don't break down in the oral cavity and secondly if somebody eats a brownie the THC itself is bound very heavily in that brownie and will be absorbed from the gastrointestinal tract but will not be to a great degree trapped in the buccal cavity. So in summary plasma protein binding is very important particularly for THC and THC acid. The other drugs on the panel the Henderson Hasselbalch equation is very important. pH of oral fluid being the driving factor in that diffusion diffusion and drugs are also trapped in buccal cavity particularly THC which is very lipid soluble. So I'm now going to go on move to a slide that discusses THC and THC acid testing in oral fluid. So let's talk about THC and THCA detection in oral fluid. THC as I have said is trapped in the buccal cavity after smoking and can be detected for the first 12 to 18 hours and maybe as long as 24 to 30 hours after a single use. Both THC and THCA are heavily plasma protein bound and there is limited transfer to oral fluid from blood serum. However THCA can be detected in oral fluid by sensitive mass spec mass spec technologies those similar to the ones used in hair testing and in that case detection window is longer in oral fluid especially for heavy users. There was considerable debate in HHS about whether to require THC testing whether to require THCA testing or whether to require the combination of both. HHS decided after that debate to require THC testing at a screening cut off of four nanograms per mil and a confirmation cut off at two nanograms per mil. It was felt by HHS that the technology needed to detect on a routine basis THCA in oral fluid was not one that could be transferred freely to those labs that would be doing oral fluid under the regulated DOT program. After passive exposure and under extreme conditions it is possible that detectable amounts of THC can be detected however as with urine the concentrations remain below the cutoff. Of course in urine it is the concentrations of THC metabolite THCA that remain below the cutoff. So in summary oral fluid testing is not unique it is used in other areas of drug testing. The HHS panels incorporated into the DOT rules have much lower concentrations for the cutoffs than urine and in the case of THC or marijuana use THC is used to detect that use and not THCA and cocaine itself has been added to the panels. There is a directly observed collection protocol therefore no specimen validity testing is required and certification of labs will occur through the standard protocols used by the National Lab Certification Program. Thank you very much for your attention and I will listen look forward to seeing you in other presentations. you

oral fluid laboratory drug testing

regulated settings

HHS approved

THC detection in oral fluid

cocaine panel