{"id":7212,"date":"2025-05-29T09:42:00","date_gmt":"2025-05-29T04:12:00","guid":{"rendered":"https:\/\/chiralpedia.com\/blog\/?p=7212"},"modified":"2025-05-29T10:46:30","modified_gmt":"2025-05-29T05:16:30","slug":"episode-5-choosing-the-right-twin-regulatory-expectations-for-single-enantiomers","status":"publish","type":"post","link":"https:\/\/chiralpedia.com\/blog\/episode-5-choosing-the-right-twin-regulatory-expectations-for-single-enantiomers\/","title":{"rendered":"Episode 5: Choosing the Right Twin: Regulatory Expectations for Single Enantiomers"},"content":{"rendered":"\n<p class=\"has-ast-global-color-0-color has-text-color has-link-color wp-elements-1c94b86fe31fd1585bb7abee901fcc96\"><strong>Tagline:<\/strong><\/p>\n\n\n\n<p class=\"has-vivid-red-color has-text-color has-link-color wp-elements-16152206636c40a309510546d6300340\"><em><strong>&#8220;When two mirror images offer different paths, how do regulators choose which one should become medicine?&#8221;<\/strong><\/em><\/p>\n\n\n\n<p class=\"has-ast-global-color-0-color has-text-color has-link-color has-medium-font-size wp-elements-81c47aea2e5cee11d71e578c65a2be9b\"><strong>Introduction<\/strong><\/p>\n\n\n\n<p>The rise of regulatory consciousness around chiral drugs in the 1990s opened a crucial new question:<br>If mirror-image molecules behave differently, how should the pharmaceutical industry -and regulators -decide which enantiomer to develop, approve, and market?<\/p>\n\n\n\n<p>This episode explores how regulatory agencies like the FDA, EMA, PMDA, CDSCO, and TGA crafted expectations for the development, approval, and control of <strong>single-enantiomer drugs<\/strong>. It covers the scientific justifications regulators demand, the critical technical requirements for purity and stability, and the ongoing clinical and ethical debates about when a single-enantiomer strategy is justified.<\/p>\n\n\n\n<p class=\"has-vivid-red-color has-text-color has-link-color wp-elements-0c7595346196535f27b81e7557f9c7ee\"><strong><em>In a world where left and right-handed molecules can change lives, choosing the right &#8220;twin&#8221; has become a matter of public trust, not just chemistry.<\/em><\/strong><\/p>\n\n\n\n<p class=\"has-ast-global-color-0-color has-text-color has-link-color has-medium-font-size wp-elements-bb4f5f391dcb8777c4511128b4c62351\"><strong>Why Develop Single Enantiomers?<\/strong><\/p>\n\n\n\n<p>Initially, racemates were the norm because they were easier and cheaper to produce. However, the increasing ability to develop single enantiomers raised new possibilities:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Higher therapeutic potency<\/strong> (e.g., esomeprazole vs. omeprazole).<\/li>\n\n\n\n<li><strong>Reduced side effects<\/strong> (e.g., levocetirizine vs. cetirizine).<\/li>\n\n\n\n<li><strong>Simpler pharmacokinetics<\/strong> with less variability.<\/li>\n\n\n\n<li><strong>Lower dose requirements<\/strong> leading to cost savings or better patient adherence.<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-image aligncenter size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"864\" height=\"894\" src=\"https:\/\/chiralpedia.com\/blog\/wp-content\/uploads\/2025\/04\/E5-01-visual-selection-1.png\" alt=\"\" class=\"wp-image-7485\" style=\"width:576px;height:auto\" srcset=\"https:\/\/chiralpedia.com\/blog\/wp-content\/uploads\/2025\/04\/E5-01-visual-selection-1.png 864w, https:\/\/chiralpedia.com\/blog\/wp-content\/uploads\/2025\/04\/E5-01-visual-selection-1-290x300.png 290w, https:\/\/chiralpedia.com\/blog\/wp-content\/uploads\/2025\/04\/E5-01-visual-selection-1-768x795.png 768w\" sizes=\"auto, (max-width: 864px) 100vw, 864px\" \/><figcaption class=\"wp-element-caption\"><mark style=\"background-color:rgba(0, 0, 0, 0);color:#dd2020\" class=\"has-inline-color\"><em>From a regulatory standpoint, developing a single-enantiomer drug could mean a <strong>clearer understanding of efficacy and safety<\/strong>, aligning with the fundamental mission of protecting public health (FDA, 1992).<\/em><\/mark><\/figcaption><\/figure>\n\n\n\n<p class=\"has-ast-global-color-0-color has-text-color has-link-color has-medium-font-size wp-elements-68a7f3689bc073d60fea75d32150c76b\"><strong>Regulatory Principles for Single Enantiomer Development<\/strong><\/p>\n\n\n\n<p>Across major agencies, several core expectations guide single-enantiomer drug development:<\/p>\n\n\n\n<p><strong>1. Early Declaration of Chirality<\/strong><\/p>\n\n\n\n<p>Drug developers are expected to <strong>identify the presence of chiral centers<\/strong> as early as possible -typically during lead optimization or preclinical development.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>FDA<\/strong>: Requires early characterization of stereochemistry at the Investigational New Drug (IND) stage (FDA, 1992).<\/li>\n\n\n\n<li><strong>EMA<\/strong>: Insists chirality be acknowledged at the beginning of the dossier (EMA, 1994).<\/li>\n\n\n\n<li><strong>PMDA and TGA<\/strong>: Follow similar expectations, often referencing ICH Q6A for quality documentation (ICH, 1999).<\/li>\n<\/ul>\n\n\n\n<p>This early identification ensures that stereochemistry is not treated as an afterthought.<\/p>\n\n\n\n<p><strong>2. Justification for Development Strategy<\/strong><\/p>\n\n\n\n<p>When a molecule is chiral, developers must justify whether they intend to market:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>A racemate,<\/li>\n\n\n\n<li>A purified single enantiomer,<\/li>\n\n\n\n<li>Or both forms sequentially (e.g., a racemate followed by a chiral switch).<\/li>\n<\/ul>\n\n\n\n<p><strong>Scientific factors considered include<\/strong>:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Differential pharmacodynamics and pharmacokinetics between enantiomers.<\/li>\n\n\n\n<li>Toxicology profiles.<\/li>\n\n\n\n<li>Stability (i.e., propensity for racemization).<\/li>\n\n\n\n<li>Technical feasibility and manufacturing cost.<\/li>\n<\/ul>\n\n\n\n<p>If the enantiomers show <strong>marked differences<\/strong> in efficacy, toxicity, or metabolism, regulators expect a strong justification for not pursuing a single-enantiomer drug (Agranat et al., 2002).<\/p>\n\n\n\n<p><strong>3. Stereoselective Pharmacology and Toxicology<\/strong> (<strong><mark style=\"background-color:rgba(0, 0, 0, 0);color:#cf2e2e\" class=\"has-inline-color\"><em>Chiral Pharmacology<\/em><\/mark><\/strong>)<\/p>\n\n\n\n<p>A central expectation is that sponsors must <strong>characterize the pharmacological and toxicological profiles of each enantiomer separately<\/strong>, unless justified otherwise.<\/p>\n\n\n\n<p>For example:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Binding affinity<\/strong> of each enantiomer to therapeutic and off-target receptors.<\/li>\n\n\n\n<li><strong>Functional activity assays<\/strong> (e.g., agonism vs. antagonism).<\/li>\n\n\n\n<li><strong>Stereoselective toxicity<\/strong> (e.g., one enantiomer causing cardiotoxicity while the other is benign).<\/li>\n<\/ul>\n\n\n\n<p><strong>FDA&#8217;s 1992 guidance<\/strong> stresses the need for separate evaluation whenever the enantiomers can be individually isolated and studied (FDA, 1992).<\/p>\n\n\n\n<p><strong>4. Enantiomeric Purity Requirements<\/strong><\/p>\n\n\n\n<p>When a single-enantiomer drug is developed, regulators impose strict requirements for <strong>chiral purity<\/strong>:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Typically <strong>\u226598% enantiomeric excess<\/strong> (ee) is expected.<\/li>\n\n\n\n<li>The undesired enantiomer is treated similarly to an impurity (distomer) and must be <strong>quantified and controlled<\/strong> (ICH, 1999).<\/li>\n\n\n\n<li>Analytical methods must be <strong>validated for enantiomeric specificity<\/strong>, typically using chiral HPLC or SFC (Lesellier, 2008).<\/li>\n<\/ul>\n\n\n\n<p>This ensures that <strong>batch-to-batch variability<\/strong> does not unintentionally affect pharmacological or safety profiles.<\/p>\n\n\n\n<p><strong>5. Chiral Stability: Racemization Assessment<\/strong><\/p>\n\n\n\n<p>If a single enantiomer is selected, developers must demonstrate that:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>It <strong>remains stable<\/strong> during manufacturing, storage, and administration.<\/li>\n\n\n\n<li>It <strong>does not undergo significant in vivo racemization<\/strong> after administration (Wainer, 1993).<\/li>\n<\/ul>\n\n\n\n<p>For example:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Thalidomide<\/strong>, with a<mark style=\"background-color:rgba(0, 0, 0, 0);color:#dd2727\" class=\"has-inline-color\"> <em>labile chiral center<\/em><\/mark>, undergoes rapid in vivo racemization, making single-enantiomer development ineffective for eliminating teratogenic risks (McBride, 1961).<\/li>\n<\/ul>\n\n\n\n<p>Thus, stability studies must include:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Forced degradation experiments.<\/li>\n\n\n\n<li>Long-term and accelerated stability studies.<\/li>\n\n\n\n<li>In vivo pharmacokinetic investigations.<\/li>\n<\/ul>\n\n\n\n<p><strong>6. CMC (Chemistry, Manufacturing, and Controls) Documentation<\/strong><\/p>\n\n\n\n<p>Quality modules of regulatory submissions must address:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Manufacturing routes designed for <strong>asymmetric synthesis<\/strong> or <strong>chiral separation<\/strong>.<\/li>\n\n\n\n<li>Specifications for <strong>chiral purity<\/strong> at the drug substance and drug product stages.<\/li>\n\n\n\n<li>Validation of <strong>chiral analytical methods<\/strong> under GMP conditions.<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-image aligncenter size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"996\" height=\"772\" src=\"https:\/\/chiralpedia.com\/blog\/wp-content\/uploads\/2025\/04\/E5-02-visual-selection.png\" alt=\"\" class=\"wp-image-7487\" style=\"width:630px;height:auto\" srcset=\"https:\/\/chiralpedia.com\/blog\/wp-content\/uploads\/2025\/04\/E5-02-visual-selection.png 996w, https:\/\/chiralpedia.com\/blog\/wp-content\/uploads\/2025\/04\/E5-02-visual-selection-300x233.png 300w, https:\/\/chiralpedia.com\/blog\/wp-content\/uploads\/2025\/04\/E5-02-visual-selection-768x595.png 768w\" sizes=\"auto, (max-width: 996px) 100vw, 996px\" \/><\/figure>\n\n\n\n<p class=\"has-vivid-red-color has-text-color has-link-color wp-elements-636769d809f00a0301af68b5c79b9a55\"><strong><em>Without robust CMC control, approval of a single-enantiomer drug may be delayed or denied.<\/em><\/strong><\/p>\n\n\n\n<p class=\"has-ast-global-color-0-color has-text-color has-link-color has-medium-font-size wp-elements-114eea7fab9cd72c906f7d9cdf1a1d82\"><strong>Case Study: Esomeprazole<\/strong><\/p>\n\n\n\n<p><strong>Esomeprazole<\/strong> (the S-enantiomer of omeprazole) offers a compelling example of how regulators applied these expectations.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Pharmacodynamics<\/strong>: Similar potency to omeprazole.<\/li>\n\n\n\n<li><strong>Pharmacokinetics<\/strong>: Reduced interindividual variability compared to racemic omeprazole.<\/li>\n\n\n\n<li><strong>Clinical Impact<\/strong>: More consistent acid suppression and better healing rates in GERD patients (Andersson, 2001).<\/li>\n\n\n\n<li><strong>Regulatory outcome<\/strong>: Approved as a new molecular entity (NME) by the FDA after demonstration of clinical advantage.<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-image aligncenter size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"732\" height=\"533\" src=\"https:\/\/chiralpedia.com\/blog\/wp-content\/uploads\/2025\/04\/E5-2.1-visual-selection.png\" alt=\"\" class=\"wp-image-7542\" style=\"width:470px;height:auto\" srcset=\"https:\/\/chiralpedia.com\/blog\/wp-content\/uploads\/2025\/04\/E5-2.1-visual-selection.png 732w, https:\/\/chiralpedia.com\/blog\/wp-content\/uploads\/2025\/04\/E5-2.1-visual-selection-300x218.png 300w\" sizes=\"auto, (max-width: 732px) 100vw, 732px\" \/><\/figure>\n\n\n\n<p>This success illustrates that single-enantiomer development is not just a regulatory checkbox -it must deliver <strong>real-world clinical benefit<\/strong> to be justified.<\/p>\n\n\n\n<p class=\"has-ast-global-color-0-color has-text-color has-link-color has-medium-font-size wp-elements-cd23f2efe340d9d389cc855c6b304c22\"><strong>Chiral Switches: Special Regulatory Considerations<\/strong><\/p>\n\n\n\n<p>When companies develop a <strong>single-enantiomer version of an already marketed racemate<\/strong> -a &#8220;<strong><mark style=\"background-color:rgba(0, 0, 0, 0);color:#cf2e2e\" class=\"has-inline-color\"><em>chiral switch<\/em><\/mark><\/strong>&#8221; &#8211; regulators impose additional scrutiny:<\/p>\n\n\n\n<p><strong>Requirements typically include<\/strong>:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Proof that the single enantiomer is not simply a &#8220;me-too&#8221; version without significant improvement.<\/li>\n\n\n\n<li>New clinical data demonstrating therapeutic advantages.<\/li>\n\n\n\n<li>Intellectual property concerns must not drive development absent clinical merit (Agranat &amp; Wainschtein, 2010).<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-image aligncenter size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"900\" height=\"478\" src=\"https:\/\/chiralpedia.com\/blog\/wp-content\/uploads\/2025\/04\/E5-03-visual-selection.png\" alt=\"\" class=\"wp-image-7491\" style=\"width:676px;height:auto\" srcset=\"https:\/\/chiralpedia.com\/blog\/wp-content\/uploads\/2025\/04\/E5-03-visual-selection.png 900w, https:\/\/chiralpedia.com\/blog\/wp-content\/uploads\/2025\/04\/E5-03-visual-selection-300x159.png 300w, https:\/\/chiralpedia.com\/blog\/wp-content\/uploads\/2025\/04\/E5-03-visual-selection-768x408.png 768w\" sizes=\"auto, (max-width: 900px) 100vw, 900px\" \/><\/figure>\n\n\n\n<p class=\"has-vivid-red-color has-text-color has-link-color wp-elements-96f35f7d39668575f70826d4234673e1\"><strong><em>Some switches have been accepted (e.g., levocetirizine) based on improved side effect profiles, while others have been viewed skeptically.<\/em><\/strong><\/p>\n\n\n\n<p class=\"has-ast-global-color-0-color has-text-color has-link-color has-medium-font-size wp-elements-6cffd2fd327305a27bfffb859ee7e2d1\"><strong>Ethical and Practical Challenges<\/strong><\/p>\n\n\n\n<p>Even with clear regulatory expectations, challenges persist:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Marginal advantages<\/strong>: Some single-enantiomer drugs offer only slight clinical improvements, raising ethical questions about pricing and marketing (Hancu &amp; Modroiu, 2022).<\/li>\n\n\n\n<li><strong>Patient confusion<\/strong>: Switching from racemate to enantiomer formulations can create adherence challenges if not clearly explained.<\/li>\n\n\n\n<li><strong>Patent extensions<\/strong>: Critics argue that some chiral switches are driven more by commercial lifecycle management than patient benefit.<\/li>\n<\/ul>\n\n\n\n<p>Regulators thus face a delicate balance between encouraging scientific innovation and protecting against strategic manipulation.<\/p>\n\n\n\n<p class=\"has-ast-global-color-0-color has-text-color has-link-color has-medium-font-size wp-elements-9e316c1999adbcade6b8c6749c3afcd7\"><strong>Conclusion<\/strong><\/p>\n\n\n\n<p>The development of single-enantiomer drugs represents a confluence of scientific, regulatory, and ethical considerations. Regulatory agencies today expect -and enforce -a sophisticated, evidence-based approach to stereochemistry.<\/p>\n\n\n\n<p>Choosing the &#8220;right twin&#8221; is no longer a matter of manufacturing convenience or commercial strategy. It is a carefully engineered process requiring proof of advantage, control of purity, assurance of stability, and clarity of clinical benefit.<\/p>\n\n\n\n<p>In the next episode, we will explore the phenomenon of <strong>chiral switches<\/strong> more deeply, examining how regulators evaluate whether a switch represents true therapeutic innovation -or simply commercial opportunism.<\/p>\n\n\n\n<p class=\"has-vivid-red-color has-text-color has-link-color wp-elements-5e672955dd9f208527288b9716b0c9e7\"><strong>What is in the next episode?<\/strong><\/p>\n\n\n\n<p><em>&#8220;When a racemate becomes two drugs, what\u2019s gained and what\u2019s lost? Join us in <mark style=\"background-color:rgba(0, 0, 0, 0);color:#da2727\" class=\"has-inline-color\">Episode 6: <strong>The Rise of the Chiral Switch: Strategy or Science?<\/strong>.<\/mark>&#8220;<\/em><\/p>\n\n\n\n<p class=\"has-ast-global-color-0-color has-text-color has-link-color has-medium-font-size wp-elements-70f1e73667f2850b676b5e58240281c9\"><strong>References<\/strong><\/p>\n\n\n\n<p>Israel Agranat &amp; Ilaria D\u2019Acquarica (2025),\u00a0<em>Racemic drugs are not necessarily less efficacious and less safe than their single-enantiomer components<\/em>. European Journal of Pharmaceutical Sciences. <a href=\"https:\/\/doi.org\/10.1016\/j.ejps.2025.107082\">https:\/\/doi.org\/10.1016\/j.ejps.2025.107082<\/a>\u00a0<\/p>\n\n\n\n<p>Hancu, G., &amp; Modroiu, A. (2022). Chiral switch: Between therapeutical benefit and marketing strategy. <em>Pharmaceuticals, 15<\/em>(2), 240.<\/p>\n\n\n\n<p>Agranat, I., Caner, H., &amp; Caldwell, J. (2002). Putting chirality to work: The strategy of chiral switches. <em>Nature Reviews Drug Discovery, 1<\/em>(10), 753\u2013768.<\/p>\n\n\n\n<p>Agranat, I., &amp; Wainschtein, S. R. (2010). The strategy of enantiomer patents of drugs. <em>Drug Discovery Today, 15<\/em>(5-6), 163\u2013170.<\/p>\n\n\n\n<p>Andersson, T. (2001). Pharmacokinetics, metabolism and interactions of acid pump inhibitors: Focus on omeprazole, lansoprazole, pantoprazole, and rabeprazole. <em>Clinical Pharmacokinetics, 40<\/em>(7), 523\u2013538.<\/p>\n\n\n\n<p>European Medicines Agency (EMA). (1994). <em>Investigation of Chiral Active Substances<\/em> (CPMP Note for Guidance 3CC29a).<\/p>\n\n\n\n<p>Food and Drug Administration (FDA). (1992). <em>Development of New Stereoisomeric Drugs<\/em> (Policy Statement). Federal Register, 57(88), 22249-22250.<\/p>\n\n\n\n<p>International Council for Harmonisation (ICH). (1999). <em>Q6A: Specifications \u2013 Test Procedures and Acceptance Criteria for New Drug Substances and New Drug Products: Chemical Substances<\/em>.<\/p>\n\n\n\n<p>Lesellier, E. (2008). The many faces of packed column supercritical fluid chromatography -A critical review. <em>Journal of Chromatography A, 1217<\/em>(11), 1560\u20131580.<\/p>\n\n\n\n<p>McBride, W. G. (1961). Thalidomide and congenital abnormalities. <em>The Lancet, 278<\/em>(7216), 1358.<\/p>\n\n\n\n<p>Wainer, I. W. (1993). The regulatory requirements for the separation, identification, quantitation, and pharmacological evaluation of the enantiomers of chiral drugs. <em>Journal of Pharmaceutical and Biomedical Analysis, 11<\/em>(6), 519\u2013526.<\/p>\n\n\n\n<p class=\"has-ast-global-color-0-color has-text-color has-link-color has-medium-font-size wp-elements-04467d121d4a3fe2d97a693c0133ceb1\"><strong>Further Reading<\/strong><\/p>\n\n\n\n<figure class=\"wp-block-embed is-type-wp-embed is-provider-chiralpedia wp-block-embed-chiralpedia\"><div class=\"wp-block-embed__wrapper\">\n<blockquote class=\"wp-embedded-content\" data-secret=\"I0r4WgDhih\"><a href=\"https:\/\/chiralpedia.com\/blog\/racemates-%e2%89%a0-less-safe-rethink-chirality\/\">Racemates Less Safe. Rethink Chirality!<\/a><\/blockquote><iframe loading=\"lazy\" class=\"wp-embedded-content\" sandbox=\"allow-scripts\" security=\"restricted\" style=\"position: absolute; visibility: hidden;\" title=\"&#8220;Racemates Less Safe. Rethink Chirality!&#8221; &#8212; Chiralpedia\" src=\"https:\/\/chiralpedia.com\/blog\/racemates-%e2%89%a0-less-safe-rethink-chirality\/embed\/#?secret=ldjUjEUX6v#?secret=I0r4WgDhih\" data-secret=\"I0r4WgDhih\" width=\"500\" height=\"282\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\"><\/iframe>\n<\/div><\/figure>\n\n\n\n<figure class=\"wp-block-embed is-type-wp-embed is-provider-chiralpedia wp-block-embed-chiralpedia\"><div class=\"wp-block-embed__wrapper\">\n<blockquote class=\"wp-embedded-content\" data-secret=\"U0mJa15QcJ\"><a href=\"https:\/\/chiralpedia.com\/blog\/chiral-drugs-a-twisted-tale-in-pharmaceuticals\/\">Chiral Drugs: A twisted tale in pharmaceuticals<\/a><\/blockquote><iframe loading=\"lazy\" class=\"wp-embedded-content\" sandbox=\"allow-scripts\" security=\"restricted\" style=\"position: absolute; visibility: hidden;\" title=\"&#8220;Chiral Drugs: A twisted tale in pharmaceuticals&#8221; &#8212; Chiralpedia\" src=\"https:\/\/chiralpedia.com\/blog\/chiral-drugs-a-twisted-tale-in-pharmaceuticals\/embed\/#?secret=fbcdZOSeWn#?secret=U0mJa15QcJ\" data-secret=\"U0mJa15QcJ\" width=\"500\" height=\"282\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\"><\/iframe>\n<\/div><\/figure>\n\n\n\n<figure class=\"wp-block-embed is-type-wp-embed is-provider-chiralpedia wp-block-embed-chiralpedia\"><div class=\"wp-block-embed__wrapper\">\n<blockquote class=\"wp-embedded-content\" data-secret=\"U2Dq6SVcwf\"><a href=\"https:\/\/chiralpedia.com\/blog\/chiral-pharmacology-the-mirror-image-of-drug-development\/\">Chiral Pharmacology: The Mirror Image of Drug Development<\/a><\/blockquote><iframe loading=\"lazy\" class=\"wp-embedded-content\" sandbox=\"allow-scripts\" security=\"restricted\" style=\"position: absolute; visibility: hidden;\" title=\"&#8220;Chiral Pharmacology: The Mirror Image of Drug Development&#8221; &#8212; Chiralpedia\" src=\"https:\/\/chiralpedia.com\/blog\/chiral-pharmacology-the-mirror-image-of-drug-development\/embed\/#?secret=HcBu98qeQq#?secret=U2Dq6SVcwf\" data-secret=\"U2Dq6SVcwf\" width=\"500\" height=\"282\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\"><\/iframe>\n<\/div><\/figure>\n\n\n\n<figure class=\"wp-block-embed is-type-wp-embed is-provider-chiralpedia wp-block-embed-chiralpedia\"><div class=\"wp-block-embed__wrapper\">\n<blockquote class=\"wp-embedded-content\" data-secret=\"azqk0AP4rq\"><a href=\"https:\/\/chiralpedia.com\/blog\/chiral-switch-unlocking-the-potential-of-single-enantiomers\/\">Chiral Switch: Unlocking the Potential of Single Enantiomers<\/a><\/blockquote><iframe loading=\"lazy\" class=\"wp-embedded-content\" sandbox=\"allow-scripts\" security=\"restricted\" style=\"position: absolute; visibility: hidden;\" title=\"&#8220;Chiral Switch: Unlocking the Potential of Single Enantiomers&#8221; &#8212; Chiralpedia\" src=\"https:\/\/chiralpedia.com\/blog\/chiral-switch-unlocking-the-potential-of-single-enantiomers\/embed\/#?secret=pHEweiNWRm#?secret=azqk0AP4rq\" data-secret=\"azqk0AP4rq\" width=\"500\" height=\"282\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\"><\/iframe>\n<\/div><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>Tagline: &#8220;When two mirror images offer different paths, how do regulators choose which one should become medicine?&#8221; Introduction The rise of regulatory consciousness around chiral drugs in the 1990s opened a crucial new question:If mirror-image molecules behave differently, how should the pharmaceutical industry -and regulators -decide which enantiomer to develop, approve, and market? This episode explores how regulatory agencies like the FDA, EMA, PMDA, CDSCO, and TGA crafted expectations for the development, approval, and control &hellip;<\/p>\n<p class=\"read-more\"> <a class=\"\" href=\"https:\/\/chiralpedia.com\/blog\/episode-5-choosing-the-right-twin-regulatory-expectations-for-single-enantiomers\/\"> <span class=\"screen-reader-text\">Episode 5: Choosing the Right Twin: Regulatory Expectations for Single Enantiomers<\/span> Read More &raquo;<\/a><\/p>\n","protected":false},"author":1,"featured_media":7705,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"site-sidebar-layout":"","site-content-layout":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","footnotes":""},"categories":[7,43,116],"tags":[23,22],"ppma_author":[93,95],"class_list":["post-7212","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-chiral-science","category-chirality","category-regulatory-affairs","tag-chiral_drugs","tag-chirality"],"authors":[{"term_id":93,"user_id":1,"is_guest":0,"slug":"chiralusrblg","display_name":"Valliappan Kannappan","avatar_url":{"url":"https:\/\/chiralpedia.com\/blog\/wp-content\/uploads\/2024\/09\/vk.jpg","url2x":"https:\/\/chiralpedia.com\/blog\/wp-content\/uploads\/2024\/09\/vk.jpg"},"first_name":"","last_name":"","user_url":"https:\/\/chiralpedia.com\/blog\/","job_title":"Founder, chiralpedia.com","description":""},{"term_id":95,"user_id":2,"is_guest":0,"slug":"chandramouli-r","display_name":"Chandramouli R","avatar_url":"https:\/\/secure.gravatar.com\/avatar\/dafe0b6a18e9248eb688088e3e993360328363d8d087bbd01648f0bddae05eb5?s=96&d=mm&r=g","first_name":"","last_name":"","user_url":"","job_title":"","description":""}],"_links":{"self":[{"href":"https:\/\/chiralpedia.com\/blog\/wp-json\/wp\/v2\/posts\/7212","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/chiralpedia.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/chiralpedia.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/chiralpedia.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/chiralpedia.com\/blog\/wp-json\/wp\/v2\/comments?post=7212"}],"version-history":[{"count":27,"href":"https:\/\/chiralpedia.com\/blog\/wp-json\/wp\/v2\/posts\/7212\/revisions"}],"predecessor-version":[{"id":7707,"href":"https:\/\/chiralpedia.com\/blog\/wp-json\/wp\/v2\/posts\/7212\/revisions\/7707"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/chiralpedia.com\/blog\/wp-json\/wp\/v2\/media\/7705"}],"wp:attachment":[{"href":"https:\/\/chiralpedia.com\/blog\/wp-json\/wp\/v2\/media?parent=7212"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/chiralpedia.com\/blog\/wp-json\/wp\/v2\/categories?post=7212"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/chiralpedia.com\/blog\/wp-json\/wp\/v2\/tags?post=7212"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/chiralpedia.com\/blog\/wp-json\/wp\/v2\/ppma_author?post=7212"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}