Related Experiment Video
Updated: Jun 6, 2026
07:38
A General Method for Detecting Nitrosamide Formation in the In Vitro Metabolism of Nitrosamines by Cytochrome P450s
Published on: September 25, 2017
New polymorphs of isonicotinamide and nicotinamide
Jinjing Li1, Susan A Bourne, Mino R Caira
1Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa.
Chemical Communications (Cambridge, England)
|November 20, 2010
Summary
New polymorphs of isonicotinamide and nicotinamide were discovered during co-crystallization experiments. Their stability was fully characterized and compared to existing crystal forms.
Area of Science:
- Solid-state chemistry
- Crystallography
- Materials science
Background:
- Isonicotinamide and nicotinamide are established co-crystal formers.
- Polymorphism is crucial for drug formulation and stability.
- Understanding crystal forms impacts material properties.
Purpose of the Study:
- To identify and characterize new polymorphs of isonicotinamide and nicotinamide.
- To establish the stability relationships between new and known crystal forms.
- To advance the understanding of co-crystal formation and polymorphism.
Main Methods:
- Attempted co-crystallization experiments were performed.
- Newly obtained crystalline materials were fully characterized.
- Stability studies were conducted to compare different polymorphs.
Main Results:
- A novel polymorph was obtained for both isonicotinamide and nicotinamide.
- The characterization of these new forms was completed.
- The thermodynamic stability of the new polymorphs relative to known forms was determined.
Conclusions:
- The discovery of new polymorphs expands the known solid forms for these compounds.
- Established stability relationships provide critical data for selecting appropriate crystal forms.
- This research contributes to the predictive understanding of co-crystal formation and polymorphism.
Related Concept Videos
01:22Antiviral Nucleoside Inhibitors
Antiviral Nucleoside InhibitorsAntiviral nucleoside inhibitors are structural analogs of natural nucleosides that interfere with viral DNA or RNA synthesis. These compounds selectively target viral polymerases due to their resemblance to host nucleosides, thereby disrupting viral genome replication.Mechanism of Acyclovir ActionAcyclovir is a guanosine analog with a three-carbon acyclic side chain. It selectively targets herpes simplex virus type 1 (HSV-1), herpes simplex virus type 2 (HSV-2),...
01:202° Amines to N-Nitrosamines: Reaction with NaNO2
Secondary amines react with nitrous acid to form N-nitrosamines, as depicted in Figure 1. Nitrous acid, a weak and unstable acid, is formed in situ from an aqueous solution of sodium nitrite and strong acids, such as hydrochloric acid or sulfuric acid, in cold conditions. In the presence of an acid, the nitrous acid gets protonated. The subsequent loss of water results in the formation of the electrophile known as nitrosonium ion.
01:27Pharmaceutical Alternatives: Polymorphic Form-Related and Particle Size-Related Therapeutic Nonequivalence
Changes in polymorphic forms can significantly influence the bioavailability of poorly soluble drugs. Although the FDA defines pharmaceutical equivalence based on having the same active ingredient, dosage form, and route of administration, it does not automatically disqualify products with different polymorphic forms. This means two products with different polymorphs can still be deemed pharmaceutically equivalent. However, polymorphic differences can affect properties like wettability,...
01:11Nomenclature of Carboxylic Acid Derivatives: Amides and Nitriles
Naming Amides
The IUPAC and common names of amides are derived from the parent carboxylic acid, by replacing the suffix “oic acid” and “ic acid,” respectively, with “amide.” In the following example, the IUPAC name ethanamide is derived from ethanoic acid, and the common name, acetamide, is obtained from acetic acid.
The IUPAC and common names of amides are derived from the parent carboxylic acid, by replacing the suffix “oic acid” and “ic acid,” respectively, with “amide.” In the following example, the IUPAC name ethanamide is derived from ethanoic acid, and the common name, acetamide, is obtained from acetic acid.
01:15Cholinergic Receptors: Nicotinic
Nicotinic receptors are ligand-gated ion channels that are activated by acetylcholine and nicotine. Upon activation, they cause a rapid increase in the permeability of cells to K+, Na+, and Ca2+, followed by depolarization and excitation. They are in the autonomic ganglia, skeletal neuromuscular junction, CNS, and adrenal medulla.
There are two types of nicotinic receptors: neuromuscular (NM/NM/N1) and neuronal (NN/NN/N2). The two families differ based on their location and selectivity to...
There are two types of nicotinic receptors: neuromuscular (NM/NM/N1) and neuronal (NN/NN/N2). The two families differ based on their location and selectivity to...
01:23Drugs Acting on Autonomic Ganglia: Stimulants
Ganglionic stimulants activate NM nicotinic receptors in autonomic ganglia, falling into two categories: nicotine mimetics [e.g., lobeline, dimethylpiperazine, tetramethylammonium] and muscarinic receptor agonists [e.g., muscarine, methacholine]. The first category's action is rapid and blocked by nicotinic receptor antagonists, while the second category's action is delayed and blocked by atropine-like agents. Nicotine, an alkaloid, affects the heart rate by stimulating sympathetic or...