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<v Speaker 1>Imagine you have a severe, like a life threatening infection.

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<v Speaker 1>You go to the pharmacy, you get your prescription, and

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<v Speaker 1>you swallow this perfectly manufactured, chemically pure antibiotic.

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<v Speaker 2>Right, you think you're safe exactly.

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<v Speaker 1>But instead of curing you, it does absolutely nothing. I mean,

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<v Speaker 1>the chemistry in the pill was completely flawless, but the

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<v Speaker 1>biology failed. It's a it's a terrifying scenario.

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<v Speaker 2>Oh absolutely. It completely shatters that illusion of binary perfection

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<v Speaker 2>we all kind of walk around with. We tend to

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<v Speaker 2>think a pill is just a pill. You know, it's

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<v Speaker 2>either medicine or it's not.

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<v Speaker 1>Yeah, it's black and white, right, But step.

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<v Speaker 2>Into the hidden world behind that plastic bottle, into the

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<v Speaker 2>actual rigorous landscape of pharmaceutical drug analysis, and you realize

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<v Speaker 2>that a chemical compound actually becoming a save, life saving medicine.

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<v Speaker 2>It's a modern miracle.

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<v Speaker 1>It is the absolute definition of a high stakes microscopic

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<v Speaker 1>obstacle course. And well, that is exactly our mission for

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<v Speaker 1>this deep dive.

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<v Speaker 2>Today.

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<v Speaker 1>We have in front of us the textbook Pharmaceutical Drug Analysis,

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<v Speaker 1>the revised second edition by Ashutoshkar.

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<v Speaker 2>A fantastic comprehensive techt.

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<v Speaker 1>It really is so whether you are a pharmacy student

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<v Speaker 1>prepping for a career in the lab, a young professional,

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<v Speaker 1>or just a learner who is insanely curious about how

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<v Speaker 1>the modern world actually functions. Under a microscope, we are

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<v Speaker 1>going to decode this whole process for you. We're covering

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<v Speaker 1>everything from the underlying philosophy of drug creation all the

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<v Speaker 1>way to the cutting edge analytical tools that guarantee purity.

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<v Speaker 2>And we really have to start with that underlying philosophy, right,

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<v Speaker 2>which medicinal chemistry today basically defines as the pursuit of

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<v Speaker 2>better drugs for a better world.

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<v Speaker 1>Yeah, we aren't just mixing standard chemicals and a beaker

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<v Speaker 1>and hoping for the best anymore.

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<v Speaker 2>Not at all. The sheer technological leaps we've made, they

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<v Speaker 2>necessitate a level of scrutiny that would have been completely

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<v Speaker 2>unimaginable just a few decades ago.

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<v Speaker 1>Okay, let's untack this because to understand how we test

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<v Speaker 1>these drugs, we really have to look at the tools

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<v Speaker 1>we use to invent them in the first place. The

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<v Speaker 1>source material highlights things like CATM right, computer aided drug modeling.

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<v Speaker 2>Yes, KDM is huge.

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<v Speaker 1>We aren't discovering drugs by accident anymore. We are literally

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<v Speaker 1>using supercomputers to physically design a molecule on a screen

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<v Speaker 1>like a three D puzzle piece meant to fit one

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<v Speaker 1>specific disease receptor perfectly exactly.

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<v Speaker 2>And we're pairing that with combinatorial chemistry, which basically means

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<v Speaker 2>we use computer controlled robotics to rapidly generate thousands of

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<v Speaker 2>slightly different molecular variations just to find the absolute most

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<v Speaker 2>potent one.

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<v Speaker 1>Right, and then delving deep into biotechnology to engineer these

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<v Speaker 1>incredibly specific molecules designed to be highly toxic to a disease,

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<v Speaker 1>but you know, virtually harmless to a human.

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<v Speaker 2>Being, which is an incredible feed of engineering.

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<v Speaker 1>It makes me think of engineering a highly advanced spacecraft.

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<v Speaker 1>You don't just bolt the titanium together, fill it with fuel,

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<v Speaker 1>and hit the launch button. You definitely shouldn't, right, Modern

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<v Speaker 1>drug development is completely defined by its pre flight inspections,

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<v Speaker 1>because when you are dealing with a microscopic chemical that

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<v Speaker 1>is potent enough to alter human biology, a single microscopic

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<v Speaker 1>flaw in the manufacturing process isn't just a simple error.

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<v Speaker 1>It's a catastrophe.

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<v Speaker 2>It is. And if we connect this to the bigger picture,

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<v Speaker 2>you start to see why the regulations are so astronomically strict.

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<v Speaker 2>Because these new drug entities are so active and so specific,

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<v Speaker 2>the risk benefit ratio has to be pegged to an

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<v Speaker 2>absolute bare minimum.

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<v Speaker 1>There's no room for air zero.

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<v Speaker 2>We are looking at strict, legally binding enforcement by official compendia,

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<v Speaker 2>So the USP, the British pharmacopia, the European pharmacopia.

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<v Speaker 1>And we hear these acronyms all the time, right, like

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<v Speaker 1>cGMP or PAIS. But these aren't just bureaucratic red tape.

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<v Speaker 2>So far from it. Current Good Manufacturing Practices or cGMP

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<v Speaker 2>is a relentless legal framework. Yeah. I mean it mandates

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<v Speaker 2>that every single piece of equipment, every scale, every thermometer

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<v Speaker 2>in a lab is calibrated and validated continuously.

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<v Speaker 1>Pais the pre approval inspections right.

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<v Speaker 2>That means the FDA or the relevant regulatory body physically

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<v Speaker 2>sends inspectors into the manufacturing plant. They audit everything before

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<v Speaker 2>a drug is even allowed to hit the market. They

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<v Speaker 2>demand that our analytical methods evolve just as fast as

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<v Speaker 2>the drugs themselves.

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<v Speaker 1>Okay, wait, I need to stop you there. This brings

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<v Speaker 1>us back to that terrifying scenario I mentioned at the

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<v Speaker 1>very start.

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<v Speaker 2>The pure pill that fails.

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<v Speaker 1>Yes, if a lab follows all these strict cGMP rules

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<v Speaker 1>and they produce a pill that is one hundred percent

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<v Speaker 1>chemically pure, how can it fail? Isn't the act of

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<v Speaker 1>ingreding exactly what it says on the bottle?

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<v Speaker 2>Well, it might be perfectly pure in the glass vial,

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<v Speaker 2>but glass viles don't have stomachs, they don't have liver

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<v Speaker 2>ensigns or intestinal walls. This is the critical transition from

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<v Speaker 2>the highly controlled realm of laboratory chemistry into the chaotic,

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<v Speaker 2>wet environment of human biology. We really have to talk

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<v Speaker 2>about bioavailability.

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<v Speaker 1>Bioavailability the textbook defines this as the rate and extent

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<v Speaker 1>to which the active ingredient is absorbed from the drug

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<v Speaker 1>product into the body or to the specific site.

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<v Speaker 2>Of action, exactly which analysts measure by tracking things like blood,

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<v Speaker 2>serum plasma levels, or even urinary excretion data. Over time,

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<v Speaker 2>medical scientists rely on blood level attainment studies as the

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<v Speaker 2>ultimate indicator of therapeutic equivalents.

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<v Speaker 1>Because if it's not in the blood, it's not working.

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<v Speaker 2>Precisely. Clinical efficacy entirely depends on how well that drug

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<v Speaker 2>actually enters your bloodstream, and there are three major factors

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<v Speaker 2>governing this the onset of therapeutic activity, the intensity of

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<v Speaker 2>the therapeutic effect, and the duration of that effect.

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<v Speaker 1>Wait, I want to dig into how a chemically perfect

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<v Speaker 1>pill fails those three factors because the source material points

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<v Speaker 1>to formulation variables, right, especially for drugs with low solubility.

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<v Speaker 2>Yeah, think about the physical characteristics of the powder inside

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<v Speaker 2>that capsule. What is the particle size, what's the crystalline structure,

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<v Speaker 2>because a molecule can arrange itself into different crystal shapes,

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<v Speaker 2>which you call polymorphs.

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<v Speaker 1>Okay, and why does that matter?

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<v Speaker 2>Well, one shape might dissolve in water in five minutes

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<v Speaker 2>while the other takes five hours. What binding agents or

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<v Speaker 2>excipients were used to pack the powder into a tablet.

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<v Speaker 2>All of these things dictate how fast that tablet actually

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<v Speaker 2>breaks apart and dissolves in gastrointestinal fluids.

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<v Speaker 1>It's like it's like having the exact, perfectly cut key

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<v Speaker 1>to unlock a door, but the key is encased in

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<v Speaker 1>this solid block of ice.

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<v Speaker 2>Oh that's a great analogy.

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<v Speaker 1>Yeah, the chemistry the shape of the key is flawless.

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<v Speaker 1>But if the ice won't melt in time for you

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<v Speaker 1>to actually use it before the body naturally eliminates it.

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<v Speaker 1>The delivery completely fails. The biology the onset is delayed,

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<v Speaker 1>the intensity never peaks, and the duration is just zero.

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<v Speaker 2>That is a brilliant way to picture it. If the

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<v Speaker 2>drug is eliminated before the ice melts, it is medically useless.

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<v Speaker 1>So knowing how incredibly crucial both this chemical purity and

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<v Speaker 1>this biological delivery are, how do scientists actually measure them?

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<v Speaker 1>How do they prove to an FDA inspector that the

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<v Speaker 1>key isn't trapped in ice and that the key itself

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<v Speaker 1>is the right shape?

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<v Speaker 2>They rely on the analyst's toolbox. It starts with establishing

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<v Speaker 2>very specific physical constants and then backing them up with

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<v Speaker 2>rigorous statistical validation. These constants are essentially the unique measurable

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<v Speaker 2>fingerprints of a pharmaceutical chemical.

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<v Speaker 1>Here's where it gets really interesting to me. We aren't

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<v Speaker 1>just talking about, you know, putting a powder on a

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<v Speaker 1>digital scale. One of the constants is specific optical rotation.

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<v Speaker 1>We are literally talking about measuring the exact angle that

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<v Speaker 1>light rotates when it passes through a molecule.

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<v Speaker 2>Yeah. We use a device called a polarimeter for this.

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<v Speaker 2>Because pharmacological activity is intimately related to the three dimensional

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<v Speaker 2>configuration of a drug molecule. Many complex drugs are chiral, meaning.

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<v Speaker 1>They have a left handed version and a right handed version.

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<v Speaker 2>Exactly chemically they have the exact same atoms, but biologically

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<v Speaker 2>they are mirror images.

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<v Speaker 1>Which matters because the receptors in your body are also

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<v Speaker 1>three D. If the drug is the right handed version,

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<v Speaker 1>it might cure your disease perfectly, but if it's the

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<v Speaker 1>left handed version, it might not fit the receptor at all,

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<v Speaker 1>or worse, it can cause terrible side effects.

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<v Speaker 2>Right, and shining polarized light through the solution tells you

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<v Speaker 2>exactly what shape you have. The textbook uses ergometrine malleot

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<v Speaker 2>as an example here to prove its optically pure and

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<v Speaker 2>safe to use, and analyst shines polarized light through a

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<v Speaker 2>one percent solution of it in water.

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<v Speaker 1>And it has to hit a specific angle.

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<v Speaker 2>It is legally required to rotate exactly between plus fifty

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<v Speaker 2>degrees and plus fifty six degrees. If it rotates ay

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<v Speaker 2>forty five degrees, the physical shape of the molecule in

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<v Speaker 2>that batch is wrong. The batch is rejected.

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<v Speaker 1>Wow, and the specificity extends to everything, doesn't it? Like weight?

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<v Speaker 1>Permeliator is used to differentiate liquids that might look completely

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<v Speaker 1>identical to the naked eye. The booknoes Araqi's oil must

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<v Speaker 1>weigh between point nine zero eight and point nine two

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<v Speaker 1>zero grams per mili leader.

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<v Speaker 2>While benzal alcohol is significantly heavier.

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<v Speaker 1>Right, it has to weigh between one point zero four

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<v Speaker 1>zero and one point zero five zero grams.

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<v Speaker 2>We also look at loss on drying, which is basically

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<v Speaker 2>a highly regulated test to measure moisture and volatile impurities.

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<v Speaker 1>I love how strict this particular test is. You don't

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<v Speaker 1>just like leave the powder out in the sun. If

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<v Speaker 1>you want to test aspirin, you have to put it

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<v Speaker 1>under reduced pressure, specifically over silica jel, which absorbs moisture

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<v Speaker 1>for exactly five hours.

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<v Speaker 2>Yes, the conditions are incredibly exact.

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<v Speaker 1>And the compendia dictates it can lose not more than

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<v Speaker 1>or nmt zero point five percent of its weight. Any

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<v Speaker 1>more than that and your aspirin is contaminated with too

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<v Speaker 1>much water or some volatile solvent.

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<v Speaker 2>What's fascinating here is how analysts manage the inevitable errors

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<v Speaker 2>that occur when measuring all these constants. Because in any

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<v Speaker 2>laboratory operating under the laws of physics errors will happen.

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<v Speaker 2>The textbook makes a vital distinction here between determinate errors

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<v Speaker 2>and indeterminate errors.

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<v Speaker 1>Determined errors are systematic, right. They are things you can

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<v Speaker 1>actually pinpoint and fix. So if your analytical balance is

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<v Speaker 1>calibrated wrong, or you're using a solvent that has a

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<v Speaker 1>known impurity in it, that's a systematic error, right.

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<v Speaker 2>And you minimize those by running parallel control tests, calibrating

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<v Speaker 2>your apparat as constantly, or wenning a blank test with

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<v Speaker 2>just the solvent.

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<v Speaker 1>But indeterminate errors are random. They are the slight, uncontrollable

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<v Speaker 1>variations in the temperature of the room, or microscopic fluctuations

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<v Speaker 1>in the electrical current running the polarimeter, or just simple

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<v Speaker 1>human observational limits.

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<v Speaker 2>You can't eliminate them physically. You have to handle them mathematically.

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<v Speaker 1>Which means we are bringing statistics into the chemistry lab.

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<v Speaker 2>Absolutely, you use statistical treatments of finite samples. Analysts look

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<v Speaker 2>at the distribution of random errors, and they use complex

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<v Speaker 2>tools like the method of least squares.

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<v Speaker 1>Let's make sure we clarify that conceptually, the method of

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<v Speaker 1>lead squares is a way to find the truth hidden

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<v Speaker 1>inside noisy data. So if you plot a bunch of

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<v Speaker 1>test results on a graph, and they look like a

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<v Speaker 1>scattered cloud of dots because of those random errors.

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<v Speaker 2>The method of lease squares is a mathematical formula that

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<v Speaker 2>draws the absolute best fitting straight line through that cloud. Right.

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<v Speaker 1>It literally minimizes the square of the distance between every

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<v Speaker 1>single dot and the line, giving you the most accurate

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<v Speaker 1>posts average of your data.

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<v Speaker 2>Which is critical because if you are testing a batch

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<v Speaker 2>of powerful heart medication, you can't just guess if a

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<v Speaker 2>weird test result was a random statistical fluke or a

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<v Speaker 2>sign of a highly toxic impurity. You need strict mathematical

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<v Speaker 2>criteria for rejecting an observation. That is what ensures the

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<v Speaker 2>data you are using to release that drug to the

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<v Speaker 2>public is scientifically sound.

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<v Speaker 1>Okay, so we've got the basics down. We're drying out

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<v Speaker 1>aspirin over silica jel, we're shining light through ergometrin. We're

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<v Speaker 1>drawing statistical lines of bentunefit. But as we discussed earlier,

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<v Speaker 1>molecules are getting vastly more complex, very much so. A

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<v Speaker 1>simple physical constant weight or optical rotation is great for

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<v Speaker 1>a relatively simple substance in a beaker, But what happens

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<v Speaker 1>when you have a massive, highly complex biological protein.

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<v Speaker 2>That is exactly where the basic toolbox hits its limit.

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<v Speaker 2>When we move into the realm of complex organic medicinal compounds,

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<v Speaker 2>biotechnological proteins, or trace level hormones, we have to rely

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<v Speaker 2>on it advance separation and detection technologies.

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<v Speaker 1>We are talking about high performance liquid chromatography HPLC.

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<v Speaker 2>HPLC is arguably the cornerstone of modern pharmaceutical analysis. It's

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<v Speaker 2>used for isolating natural active compounds, essaying cephalosporins, which is

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<v Speaker 2>a major class of antibiotics, and controlling microbiological processes.

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<v Speaker 1>Let's explain how this actually works for everyone, because it

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<v Speaker 1>sounds intimidating. Chromatography at its core is kind of like

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<v Speaker 1>a racetrack. You have a stationary phase, which is the

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<v Speaker 1>track itself, often packed inside a metal column.

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<v Speaker 2>Okay, I like this analogy, and you have a.

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<v Speaker 1>Mobile phase, which is a liquid solvent pumped through the

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<v Speaker 1>column under incredibly high pressure. You inject your drug sample

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<v Speaker 1>into this liquid flow. Now, as the mixture travels down

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<v Speaker 1>the column, different molecules stick to the track differently based

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<v Speaker 1>on their specific chemical properties.

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<v Speaker 2>So some move fast, some move slow.

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<v Speaker 1>Exactly some molecules breeze right through and others lag behind.

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<v Speaker 1>By the time they reach the detector at the finish line,

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<v Speaker 1>they have separated completely.

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<v Speaker 2>In the level of separation we can achieve with this

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<v Speaker 2>racetrack is just staggering. The textbook highlights this with insulin,

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<v Speaker 2>specifically differentiating human insulin from poor sign or pig insulin.

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<v Speaker 1>This is a huge deal because for a long time,

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<v Speaker 1>diabetics had to use animal insulin, which could cause bad

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<v Speaker 1>immune reactions. Human insulin is much safer, but the two

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<v Speaker 1>proteins are incredibly similar. Telling them apart is notoriously.

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<v Speaker 2>Difficult, very difficult to do it. Animals have to use

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<v Speaker 2>a very specific HPLC setup. They use a vite ac

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<v Speaker 2>C eighteen column, which is a specific type of stationary track.

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<v Speaker 2>They maintain the column at exactly forty degrees celsius just

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<v Speaker 2>to control the viscosity of the flow. Everything has to

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<v Speaker 2>be perfect everything. They use a highly specialized liquid mobile

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<v Speaker 2>phase and the detection at the finish line happens by

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<v Speaker 2>shining ultraviolet light at a wavelength of exactly two hundred

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<v Speaker 2>and fourteen nanimeters.

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<v Speaker 1>And even with all of that, the peaks on the

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<v Speaker 1>read out basically the visual representation of the molecules crossing

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<v Speaker 1>the finish line. They are incredibly close together. The compendious

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<v Speaker 1>states that if the resolution between those two peaks isn't

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<v Speaker 1>at least one point three, the test is invalid. You

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<v Speaker 1>cannot legally certify the batch as pure human insulin.

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<v Speaker 2>It's a remarkable level of precision. But HPLC is designed

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<v Speaker 2>for analyzing the drug itself, usually during manufacturing, and this

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<v Speaker 2>raises an important question. What do we do when the

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<v Speaker 2>drug is no longer in a clean factory environment.

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<v Speaker 1>Oh, like when it's in a person?

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<v Speaker 2>Right? How do we detect drugs at absolute trace levels

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<v Speaker 2>like picograms floating around in a chaotic complex human fluid

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<v Speaker 2>like blood plasma? Right?

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<v Speaker 1>Yeah, you can't just pump a patient's blood through an

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<v Speaker 1>HPLC racetrack to find a microscopic trace of a barbiturate.

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<v Speaker 1>I mean, it would completely clog the machine.

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<v Speaker 2>It would ruin it. This is where the textbook introduces

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<v Speaker 2>radioimmunoassay or RIA RIA.

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<v Speaker 1>The book says it's a technique based on haptin determinants

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<v Speaker 1>and competitive antibody binding using isotopically labeled compounds.

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<v Speaker 2>Let's translate that a bit lese. A haptin is just

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<v Speaker 2>a small molecule that can't trigger an immune response on

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<v Speaker 2>its own, but it can if you attach it to

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<v Speaker 2>a larger carrier protein. By doing that in a lab,

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<v Speaker 2>scientists can essentially force an animal to create antibodies that

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<v Speaker 2>are perfectly designed to target one specific drug molecule.

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<v Speaker 1>Okay, So once you have those highly specific antibodies, ARIA

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<v Speaker 1>is widely used for analyzing drugs like morphine, hydromorphone, clonazepam,

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<v Speaker 1>and flunosolide directly in human plasma.

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<v Speaker 2>Yes, when I.

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<v Speaker 1>Was trying to visualize the actual mechanism of how this

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<v Speaker 1>test is performed, I realized Ria is basically a microscopic,

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<v Speaker 1>high stakes game of musical chairs.

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<v Speaker 2>It absolutely is. Let's break that down. How does that work?

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<v Speaker 1>So think about a test tube. The antibodies that the

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<v Speaker 1>analysts put in the tube are the chairs. There is

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<v Speaker 1>a limited, strictly fixed number of them. Now, the analysts

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<v Speaker 1>introduce the players to the game.

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<v Speaker 2>Right.

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<v Speaker 1>The players are a mixture of two things, radioactive artificially

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<v Speaker 1>labeled drug molecules that the analysts add themselves and the

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<v Speaker 1>actual unlabeled drug molecules from the patient's blood sample.

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<v Speaker 2>And all those molecules are the exact same shape, so

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<v Speaker 2>they're all fighting for those limited antibodied chairs exactly.

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<v Speaker 1>It's competitive binding. The radioactive molecules and the patient's drug

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<v Speaker 1>molecules compete to sit down. When the reaction reaches equilibrium.

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<v Speaker 1>When the music stops, you literally wash away any molecules

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<v Speaker 1>that didn't get a seat.

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<v Speaker 2>You're out of the game right now.

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<v Speaker 1>Because you know exactly how many radioactive molecules you started with.

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<v Speaker 1>You simply measure the radioactivity of the ones that manage

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<v Speaker 1>to get a chair.

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<v Speaker 2>And the math here is just beautifully simple in its logic.

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<v Speaker 2>If the radioactivity left in the tube is really low,

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<v Speaker 2>it means the patient's blood was absolutely flooded with the

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<v Speaker 2>actual drug, and the actual drug stole all the seats

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<v Speaker 2>from the radioactive ones.

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<v Speaker 1>Yeah. By measuring the radioactive losers, you can calculate the

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<v Speaker 1>exact concentration of the drug in the patient's plasma.

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<v Speaker 2>It is an ingenious mechanism, really is. And the reason

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<v Speaker 2>RIA is so incredibly powerful for clinical monitoring is because

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<v Speaker 2>of its combined isotope dilution and stereospecificity. The antibodies we

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<v Speaker 2>use as chairs are so specific they will only accept

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<v Speaker 2>that exact molecular shape, completely ignoring the thousands of other

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<v Speaker 2>proteins and chemicals naturally floating in a patient's blood. It's amazing.

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<v Speaker 2>It allows us to monitor the pharmacokinetics, basically, how the

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<v Speaker 2>drug is moving through a patient's body in real time,

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<v Speaker 2>at concentration levels that were completely invisible to science thirty

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<v Speaker 2>years ago.

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<v Speaker 1>So what does this all mean for us? We've journeyed

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<v Speaker 1>from the high minded philosophy of medicinal chemistry, you know,

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<v Speaker 1>using supercomputers to build better drugs for a better world,

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<v Speaker 1>right down to the invisible, statistical and radioactive battles happening

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<v Speaker 1>in test tubes to guarantee those drugs actually work in

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<v Speaker 1>a human stomach.

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<v Speaker 2>It is a true testament to the rigorous, often completely

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<v Speaker 2>unappreciated work of the pharmaceutical analyst. They are the gatekeepers.

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<v Speaker 2>They are the only thing standing between a theoretical chemical

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<v Speaker 2>breakthrough and a practical, safe cure.

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<v Speaker 1>Adapting our specific focus as educational content creators for you

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<v Speaker 1>the listener, whether you are prepping for a lab, practical

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<v Speaker 1>or you're just fascinated by the science of medicine, we

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<v Speaker 1>want to do a quick mental exercise to reinforce what

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<v Speaker 1>we've unpacked today. Are you ready?

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<v Speaker 2>That's good?

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<v Speaker 1>Think back to the transition from the lab to human biology.

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<v Speaker 1>The key in the block of ice. Can you name

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<v Speaker 1>the three major factors that govern a drug's efficacy through

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<v Speaker 1>its bioavailability? Take a second, think about it, got it?

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<v Speaker 1>It's the onset of therapeutic activity, the intensity of the

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<v Speaker 1>therapeutic effect, and the duration of that effect. If those

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<v Speaker 1>three don't align perfectly in the body, driven by formulation

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<v Speaker 1>variables like particle size, the chemical purity in the lab

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<v Speaker 1>simply doesn't matter.

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<v Speaker 2>And that reality brings me to a quote from the

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<v Speaker 2>source material that perfectly captures this endless, relentless pursuit of precision.

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<v Speaker 2>It's some zick Meister and Chalmooky who wrote, every scientific

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<v Speaker 2>advance is an advance in method. The invention of a

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<v Speaker 2>new specialized laboratory procedure brings about rapid conquests and new

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<v Speaker 2>fields of science and technology. Finally, it exhausts itself and

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<v Speaker 2>is replaced by still more practical method.

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<v Speaker 1>We build the polarimeter, we build the HPLC column, and

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<v Speaker 1>eventually we replace them with something even better, always pushing

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<v Speaker 1>the boundary of what we can see, which.

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<v Speaker 2>Leads us with a profound question to ponder as we

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<v Speaker 2>wrap up. As our analytical methods become so incredibly sensitive,

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<v Speaker 2>like advanced HPLC and ria that they could detect a

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<v Speaker 2>single solitary rogue molecule in a batch of millions, will

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<v Speaker 2>our very definition of a pure drug eventually have to

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<v Speaker 2>change entirely? At what point does a microscopic trace impurity

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<v Speaker 2>simply cease to matter to human biology? And how will

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<v Speaker 2>the analytical gatekeepers of the future draw that line.

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<v Speaker 1>That is a fascinating thought to leave on, because right now,

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<v Speaker 1>when we open that medicine cabinet, we expect absolute binary perfection,

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<v Speaker 1>but ensuring that perfection is a constant, rigorous fight against

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<v Speaker 1>the messy realities of chemistry, statistics, and biology. Thanks for

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<v Speaker 1>joining us on this deep dive. Keep questioning the things

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<v Speaker 1>you assume are simple, and we'll catch you on the

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<v Speaker 1>next one.