The effect of drug concentration on the thermal (dark) degradation of promethazine hydrochloride in aqueous solution
| Autor: | David James Geler Davies, John Stevens, B. J. Meakin |
|---|---|
| Rok vydání: | 1978 |
| Předmět: |
Pharmacology
Chromatography Gas Hot Temperature Aqueous solution Promethazine Hydrochloride Inorganic chemistry Electric Conductivity Pharmaceutical Science chemistry.chemical_element Darkness Hydrogen-Ion Concentration Kinetic energy Promethazine Micelle Oxygen Solutions Kinetics chemistry.chemical_compound Monomer Drug Stability chemistry Ionic strength Degradation (geology) Micelles |
| Zdroj: | Journal of Pharmacy and Pharmacology. 30:75-80 |
| ISSN: | 2042-7158 0022-3573 |
| DOI: | 10.1111/j.2042-7158.1978.tb13165.x |
| Popis: | The thermal (dark) degradation of promethazine hydrochloride in aqueous solution presents a complex kinetic picture. The process is oxygen dependent and is modified by EDTA. In citrate buffer, pH 4·0, ionic strength 0·5m, containing 0·1 % EDTA, the thermal degradation at 90° can be fitted to first order rate plots at drug concentrations up to 1·56 × 10−2m (0·5%) and to zero order rate plots at drug concentrations greater than 9·35 × 10−2m (3·0%). At intermediate concentrations no simple equation can describe the data. These effects have been correlated with the formation of drug micelles and the rate data have been interpreted on the basis of a first order monomer process and a half order micellar process occurring simultaneously. |
| Databáze: | OpenAIRE |
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