Related Experiment Video
Updated: May 9, 2026

Synthesis of pH Dependent Pyrazole, Imidazole, and Isoindolone Dipyrrinone Fluorophores using a Claisen-Schmidt Condensation Approach
Published on: June 10, 2021
Chemical stability of perphenazine
1Pharmaceutics Division, University of Houston, Houston, Texas.
Abstract:
The stability of perphenazine in oral liquid dosage forms was studied by means of a stability-indicating high-performance liquid chromatography assay method that was developed in our laboratory. There was a direct relationship between the peak heights and the concentrations, with an r value of 0.998. The percent relative standard deviation based on five injections was 0.6. The products of decomposition and excipients present in the dosage forms did not interfere with the developed assay method. The dosage forms were stable for only 30 days when stored in amber-colored glass bottles at room temperature. The pH value of the mixtures remained constant at 3.7 after 90 days of storage, and the physical appearance of the mixtures did not change. The beyond-use date of 30 days is recommended for this procduct.
Related Concept Videos
Radical Reactivity: Steric Effects
Along with electronic factors, steric factors also account...
Acidity and Basicity of Alcohols and Phenols
Stability of Substituted Cyclohexanes
The two chair conformations of cyclohexanes undergo rapid interconversion at room temperature. Both forms have identical energies and stabilities, each comprising equal amounts of the equilibrium mixture. Replacing a hydrogen atom with a functional group makes the two conformations energetically non-equivalent.
For example, in...
Drug Product Stability
Nonlinear Pharmacokinetics: Dependence of Elimination Half-Life and Dose Clearance
A study on guinea pigs examined the...
Stability of Conjugated Dienes
A comparison of the enthalpies of hydrogenation of dienes reveals that conjugated dienes release less heat on hydrogenation, rendering them more stable than their nonconjugated analogs.

