Related Experiment Video
Updated: Jan 10, 2026

Inactivation of Pathogens via Visible-Light Photolysis of Riboflavin-5′-Phosphate
Published on: April 6, 2022
Riboflavin-sensitized photoinduced degradation of donepezil hydrochloride: kinetic and computational insights for
Tooba Khan1, Zubair Anwar1, Reem Altaf2
1Department of Pharmaceutical Chemistry, Baqai Institute of Pharmaceutical Sciences, Baqai Medical University Gadap Road, Superhighway Karachi-75340 Pakistan zubair_ana@hotmail.com zubair_ana@baqai.edu.pk.
Abstract:
Donepezil (DPZ) photosensitized degradation by riboflavin (RF) at pH 2.0-12.0 has been carried out in aerobic and anaerobic conditions under UV and visible irradiation to give an idea to pharmaceutical formulators to develop a stable co-formulation to administer to elderly patients with neurodegenerative diseases (Alzheimer's disease, Parkinson's disease). The photolysis rate constants (k obs) in aerobic and anaerobic conditions in the presence of RF (0.1-0.5 × 10-4 M) range from 0.25-11.5 and 0.025-1.120 × 10-2 min-1, respectively. RF catalyzes the photodegradation of DPZ, and the second-order (k 2) constants in aerobic and anaerobic conditions range from 0.32 to 8.22 and 0.032 to 0.805 × 10-2 M-1 min-1, respectively, indicating that with an increase in the concentrations of RF, the rate of photolysis of DPZ also increases. The k-pH profile shows a bell-shaped curve from pH 2.0 to 4.0 and from pH 5.0 to 12.0, forming a sigmoid curve. The two-component spectrometric and HPLC green methods have been developed and validated for estimating DPZ and RF in pure and degraded solutions. Additionally, computational studies have been conducted to assess the formation of the ground-state complex, binding affinity, and molecular interactions between DPZ and RF.
More Related Videos
05:46Identification of Pharmaceuticals in The Aquatic Environment Using HPLC-ESI-Q-TOF-MS and Elimination of Erythromycin Through Photo-Induced Degradation
Published on: August 1, 2018
13:17In Vitro and In Vivo Evaluation of Photocontrolled Biologically Active Compounds - Potential Drug Candidates for Cancer Photopharmacology
Published on: September 29, 2023
Related Concept Videos
Factors Affecting Dissolution: Drug Permeability, Stability and Stereochemistry
Pharmacokinetics in Geriatric Patients: Effect of Age on Drug Absorption
Drug Product Stability
Protein-Drug Binding: Mechanism and Kinetics
Various forces drive these interactions, including hydrogen bonds, hydrophobic interactions, ionic bonds, electrostatic interactions, and van der Waals forces. These bonds enable drugs to bind to specific sites on proteins,...
Pharmacokinetics in Geriatric Patients: Effect of Age on Drug Metabolism
Pharmacokinetics in Geriatric Patients: Effect of Age on Drug Distribution