Related Concept Videos

Keto–Enol Tautomerism: Mechanism01:14

Keto–Enol Tautomerism: Mechanism

The keto and enol forms are known as tautomers and they constantly interconvert (or tautomerize) between the two forms under acid or base catalyzed conditions. Both the reactions involve the same steps—protonation and deprotonation— although in the reverse order.
Drug Delivery: Enteral Route01:18

Drug Delivery: Enteral Route

The enteral drug administration involves three primary routes: oral, sublingual, and buccal. Oral ingestion is the most prevalent, safe, economical, and convenient method for drug administration. However, it has certain drawbacks, including limited absorption due to the drug's low water solubility or poor membrane permeability, possible emesis from GI mucosa irritation, destruction of drugs by digestive enzymes or low gastric pH, and irregular absorption along with food or other drugs.
Drugs in...
Routes of Drug Administration: Enteral01:18

Routes of Drug Administration: Enteral

Medications can be administered through the enteral route using liquids, capsules, or tablets.
Enteral administration involves drug administration via the mouth in two ways: orally or sublingually.
Unlike sublingually drugs, drugs that are taken orally pass through the gastrointestinal (GI) tract and get metabolized by the liver. Once metabolized, the drug is absorbed into the systemic circulation, reaching different body parts via the bloodstream. However, while passing through the stomach,...
Chemotherapy-Induced Nausea and Vomiting: Neurokinin-1 Receptor Antagonists01:28

Chemotherapy-Induced Nausea and Vomiting: Neurokinin-1 Receptor Antagonists

Neurokinin 1 (NK1) receptors are distributed across the GI tract, vagal afferents, and key CNS regions including the central vomiting center and chemoreceptor trigger zone (CTZ) Chemotherapy agents stimulate enterochromaffin cells in the gastrointestinal (GI) tract to release large amounts of substance P (SP). SP is a neuropeptide released by specific sensory nerves in response to many different stressors, including those in the GI mucosa affected by chemotherapy.  SP binds and activates these...
Oral Drug Delivery Systems: Delayed-Release Systems01:11

Oral Drug Delivery Systems: Delayed-Release Systems

Delayed-release drug delivery systems are specialized pharmaceutical formulations designed to postpone the release of active compounds until the drug reaches a specific region of the gastrointestinal (GI) tract, typically the intestine. These systems are essential for drugs that may cause gastric irritation, are unstable in acidic environments, or need to exert therapeutic effects locally in the intestinal or colonic regions.The core feature of delayed-release systems is the use of enteric...
Types of Enols and Enolates01:19

Types of Enols and Enolates

Aldehydes and ketones form enols, although only about 1% of the enol is present at the equilibrium for simple monocarbonyl compounds. The enol form is undetectable for acetaldehyde, present as only 1.5 × 10−4 % of acetone, and present as only 1.2% of cyclohexanone. Two kinds of regioisomeric enols are possible for unsymmetrical ketones, and their net composition is 1% at equilibrium. This instability is due to the lower bond energy of C=C than the C=O group. The additional instability of enols...