Related Experiment Videos
Physiochemical properties of phenobarbital solid dispersion with phosphatidylcholine
M Fujii1, K Harada, M Matsumoto
1Showa College of Pharmaceutical Sciences, Tokyo, Japan.
Chemical & Pharmaceutical Bulletin
|August 1, 1990
Summary
Phenobarbital solid dispersions with phosphatidylcholine maintain an amorphous state under specific ratios. Interactions are influenced by phenobarbital
Area of Science:
- Pharmaceutical Sciences
- Materials Science
- Physical Chemistry
Background:
- Solid dispersions (SD) enhance drug solubility and bioavailability.
- Phosphatidylcholine (PC) is a common excipient in pharmaceutical formulations.
- Phenobarbital (PB) is an antiepileptic drug with poor aqueous solubility.
Purpose of the Study:
- To investigate the formation and properties of phenobarbital-phosphatidylcholine solid dispersions.
- To elucidate the interaction mechanisms between phenobarbital and phosphatidylcholine.
- To determine the factors influencing the amorphous state of phenobarbital in solid dispersion.
Main Methods:
- Preparation of phenobarbital-phosphatidylcholine solid dispersions at various mole fractions.
- Characterization using infrared (IR) spectroscopy and X-ray diffraction (XRD).
- Thermal analysis using differential scanning calorimetry (DSC).
Main Results:
- Phenobarbital remained amorphous in SDs with mole fractions below 0.75.
- Hydrogen bonding was observed between phenobarbital (PB) and phosphatidylcholine (PC) via IR spectroscopy (1:1 ratio).
- Thermal events (endothermic and exothermic peaks) indicated a metastable to stable state transition at 70°C for PB mole fractions < 0.50.
Conclusions:
- Phenobarbital-phosphatidylcholine interactions are governed by both chemical structure and molecular shape.
- Chemical structure influences interaction with PC, while molecular shape dictates lattice arrangement.
- The amorphous state stability of phenobarbital in SDs is comparable to indomethacin and influenced by its chemical similarity to phenytoin.