- Radioiodination and biological evaluation of nizatidine as a new highly selective radiotracer for peptic ulcer disorder detection. [Journal Article]
- JLJ Labelled Comp Radiopharm 2017; 60(13):600-607
- Nizatidine has been labeled using [125I] with chloramine-T as oxidizing agent. Factors such as the amount of oxidizing agent, amount of substrate, pH, reaction temperature, and reaction time have bee...
Nizatidine has been labeled using [125I] with chloramine-T as oxidizing agent. Factors such as the amount of oxidizing agent, amount of substrate, pH, reaction temperature, and reaction time have been systematically studied to optimize the iodination. Biodistribution studies indicate the suitability of radioiodinated nizatidine as a novel tracer to image stomach ulcer. Radioiodinated nizatidine may be considered a highly selective radiotracer for peptic ulcer imaging.
- Development of a Validated Comparative Stability-Indicating Assay Method for Some H2-Receptor Antagonists. [Journal Article]
- JCJ Chromatogr Sci 2017 Sep 01; 55(8):818-831
- A comparative force degradation high performance thin layer chromatography (HPTLC) method was developed and validated for some H2-receptor antagonists. The studied H2-receptor antagonists were raniti...
A comparative force degradation high performance thin layer chromatography (HPTLC) method was developed and validated for some H2-receptor antagonists. The studied H2-receptor antagonists were ranitidine (RAN), nizatidine (NIZ) and famotidine (FAM). The degradation behaviors of the studied H2-receptor antagonists were studied under different stress conditions (hydrolytic, thermal and oxidative) conditions as well as storage conditions according to International Conference on Harmonization (ICH) recommendations. A stability-indicating HPTLC method was optimized in order to separate the analyte from the degradation products formed under various stress conditions. Full separation of the drugs from their degradation products was successfully achieved on an HPTLC precoated silica gel plates. Densitometric measurements were carried out using a Camag TLC Scanner III in the absorbance mode at 320 nm for RAN and NIZ, and 280 nm for FAM. The limits of detection and limits of quantitation range were 5.47-9.37 and 16.30-31.26 ng/band, respectively, for all investigated drugs. The validation studies were performed according to ICH requirements. The developed method was simple, rapid and reliable hence it could be applied for routine quality control analysis of the investigated H2-receptor antagonists in dosage forms. The kinetic behavior, degradation rate constants and half-lives of the degradation of the investigated drugs were studied and compared at different stress conditions. The present study provides, for the first time, a new vision to compare the degradation kinetics of H2-receptor antagonists at the same degradation procedures.
- Degradation of nitro-based pharmaceuticals by UV photolysis: Kinetics and simultaneous reduction on halonitromethanes formation potential. [Journal Article]
- WRWater Res 2017 Aug 01; 119:83-90
- This study investigated the degradation kinetics and halonitromethanes formation potential (HNMsFP) of two nitro-based pharmaceuticals (i.e., ranitidine (RNTD) and nizatidine (NZTD)) during ultraviol...
This study investigated the degradation kinetics and halonitromethanes formation potential (HNMsFP) of two nitro-based pharmaceuticals (i.e., ranitidine (RNTD) and nizatidine (NZTD)) during ultraviolet (UV) photolysis. It was found that the degradation kinetics of RNTD and NZTD exhibited pH-dependent trends, in accordance with their deprotonation equilibria. The neutral species of RNTD and NZTD were more photo-reactive than their corresponding deprotonated species, with their specific fluence-based first-order rate constants varying in the range of 5.64-31.90 m(2) E(-1). Both the RNTD and NZTD were prone precursors of HNMs (with molar yields of 5.6± 0.3% and 4.7± 0.4%, respectively at pH 7.0). Acidic and neutral circumstances facilitated the HNMs formation. The UV photolysis of RNTD and NZTD could reduce their HNMsFP simultaneously. Positive linear relationships between residual RNTD or NZTD concentration and HNMsFP were observed and the denitration during the UV photolysis accounted for the HNMsFP reduction. With the mandatory UV disinfection fluences in China (i.e. 20-80 mJ cm(-2)), the effective abatement of RNTD and NZTD and their HNMsFP could not be fully achieved, highlighting the necessity of increasing UV fluence or developing UV-based advanced oxidation process in future.
- Molecular mobility in the supercooled and glassy states of nizatidine and perphenazine. [Journal Article]
- EJEur J Pharm Sci 2017 Mar 01; 99:147-151
- The dielectric properties of two pharmaceuticals nizatidine and perphenazine were investigated in the supercooled liquid and glassy states by broadband dielectric spectroscopy. Two relaxation process...
The dielectric properties of two pharmaceuticals nizatidine and perphenazine were investigated in the supercooled liquid and glassy states by broadband dielectric spectroscopy. Two relaxation processes were observed in both the pharmaceuticals. The relaxation process observed above the glass transition temperature is the structural alpha relaxation and below the glass transition temperature is the gamma relaxation of intramolecular origin. The Johari-Goldstein beta relaxation coming from the motion of the entire molecule is found to be hidden under the structural relaxation peak in both the pharmaceuticals.
- Proliferative Effects of Histamine on Primary Human Pterygium Fibroblasts. [Journal Article]
- MIMediators Inflamm 2016; 2016:9862496
- CONCLUSIONS: Histamine may play an important role in the proliferation of HPFs and act through H1R.
- Acotiamide improves stress-induced impaired gastric accommodation. [Journal Article]
- NMNeurogastroenterol Motil 2017; 29(4)
- CONCLUSIONS: Acotiamide prolongs gastric accommodation and improves stress-induced impaired gastric accommodation, indicating a potential role for acotiamide in the treatment of functional dyspepsia through its effects on gastric accommodation reactions.
- The Slow Relaxation Dynamics in the Amorphous Pharmaceutical Drugs Cimetidine, Nizatidine, and Famotidine. [Journal Article]
- JPJ Pharm Sci 2016; 105(12):3573-3584
- The slow molecular mobility in the amorphous solid state of 3 active pharmaceutical drugs (cimetidine, nizatidine, and famotidine) has been studied using differential scanning calorimetry and the 2 d...
The slow molecular mobility in the amorphous solid state of 3 active pharmaceutical drugs (cimetidine, nizatidine, and famotidine) has been studied using differential scanning calorimetry and the 2 dielectric-related techniques of dielectric relaxation spectroscopy and thermally stimulated depolarization currents. The glass-forming ability, the glass stability, and the tendency for crystallization from the equilibrium melt were investigated by differential scanning calorimetry, which also provided the characterization of the main relaxation of the 3 glass formers. The chemical instability of famotidine at the melting temperature and above it prevented the preparation of the amorphous for dielectric studies. In contrast, for cimetidine and nizatidine, the dielectric study yielded the main kinetic features of the α relaxation and of the secondary relaxations. According to the obtained results, nizatidine displays the higher fragility index of the 3 studied glass-forming drugs. The thermally stimulated depolarization current technique has proved useful to identify the Johari-Goldstein relaxation and to measure τβJG in the amorphous solid state, that is, in a frequency range which is not easily accessible by dielectric relaxation spectroscopy.
- Molecular Encapsulation of Histamine H₂-Receptor Antagonists by CucurbitUril: An Experimental and Computational Study. [Journal Article]
- MMolecules 2016 Sep 06; 21(9)
- The histamine H₂-receptor antagonists cimetidine, famotidine and nizatidine are individually encapsulated by macrocyclic cucurbituril (CB), with binding affinities of 6.57 (±0.19) × 10³ M(-1), ...
The histamine H₂-receptor antagonists cimetidine, famotidine and nizatidine are individually encapsulated by macrocyclic cucurbituril (CB), with binding affinities of 6.57 (±0.19) × 10³ M(-1), 1.30 (±0.27) × 10⁴ M(-1) and 1.05 (±0.33) × 10⁵ M(-1), respectively. These 1:1 host-guest inclusion complexes have been experimentally examined by ¹H-NMR, UV-visible spectroscopic titrations (including Job plots), electrospray ionization mass spectrometry (ESI-MS), and isothermal titration calorimetry (ITC), as well as theoretically by molecular dynamics (MD) computation. This study may provide important insights on the supramolecular formulation of H₂-receptor antagonist drugs for potentially enhanced stability and controlled release based on different binding strengths of these host-guest complexes.
- Comparative effectiveness of histamine-2 receptor antagonists as short-term therapy for gastro-esophageal reflux disease: a network meta-analysis. [Review]
- IJInt J Clin Pharmacol Ther 2016; 54(10):761-70
- To evaluate the efficacy of members of the H2RA family for the treatment of gastro-esophageal reflux disease (GERD). We performed a thorough electronic search on PubMed, EMBASE, and the Cochrane Cent...
To evaluate the efficacy of members of the H2RA family for the treatment of gastro-esophageal reflux disease (GERD). We performed a thorough electronic search on PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) for eligible randomized clinical trials that investigated H2RAs and the treatment of GERD up to July 28, 2015. A comprehensive network meta-analysis was conducted to compare the effects of each subset of H2RAs. A total of 13 randomized controlled trials (RCTs) were included in our network meta-analysis. Our results showed that, compared with placebos, H2RAs were more effective for the treatment of GERD. Within the H2RA family, famotidine 80 mg per day (OR = 0.17, 95% CI: 0.06 - 0.38) was determined to be the most effective, followed by famotidine 40 mg per day (odds ratio (OR) = 0.23, 95% confidence interval (CI), 0.11 - 0.44); ranitidine 1,200 mg per day (OR, 0.32; 95% CI, 0.13 - 0.63); ranitidine 600 mg per day (OR, 0.27; 95% CI, 0.14 - 0.47); ranitidine 300 mg per day (OR, 0.31; 95% CI, 0.15 - 0.55); cimetidine 1,600 mg per day (OR, 0.36; 95% CI, 0.14 - 0.73); nizatidine 600 mg per day (OR, 0.58; 95% CI, 0.24 - 1.24); and finally nizatidine 300 mg per day (OR, 0.61; 95% CI, 0.25 - 1.26). The placebo was determined to be the least effective treatment. Compared with other H2RAs, famotidine had the best short-term therapeutic effect in adults with GERD, especially at a dosage of 80 mg per day.
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- Rejection of pharmaceutically-based N-nitrosodimethylamine precursors using nanofiltration. [Journal Article]
- WRWater Res 2016 Apr 15; 93:179-86
- N-Nitrosodimethylamine (NDMA) is a disinfection by-product (DBP) with many known precursors such as amine-containing pharmaceuticals that can enter the environment via treated wastewater. Reverse osm...
N-Nitrosodimethylamine (NDMA) is a disinfection by-product (DBP) with many known precursors such as amine-containing pharmaceuticals that can enter the environment via treated wastewater. Reverse osmosis and tight nanofiltration membranes (MW cutoff < 200 Da) are treatment technologies that demonstrate high removal of many compounds, but at relatively high energy costs. Looser membranes (>200 Da) may provide sufficient removal of a wide range of contaminants with lower energy costs. This study examined the rejection of pharmaceuticals that are known NDMA precursors (∼300 Da) using nanofiltration (MW cutoff ∼350 Da). MQ water was compared to two raw water sources, and results illustrated that NDMA precursors (as estimated by formation potential testing) were effectively rejected in all water matrices (>84%). Mixtures of pharmaceuticals vs. single-spiked compounds were found to have no impact on rejection from the membranes used. The use of MQ water vs. surface waters illustrated that natural organic matter, colloids, and inorganic ions present did not significantly impact the rejection of the amine-containing pharmaceuticals. This study illustrates that NDMA formation potential testing can be effectively used for assessing NDMA precursor rejection from more complex samples with multiple and/or unknown NDMA precursors present, such as wastewater matrices.