title: [Stability of penicillin potassium with linear degradation programmed humidifying experiments].
abstract: A linear degradation humidifying model for drug stability experiment is introduced. This new humidifying model is presented as: H(r) = -M1-ln {exp(- MH(r,0)) - [exp(-MH(r,0)) -exp(-MH(r-m)) t(m)-t}. Where H(r) is the relative humidity; t is the time; H(r,m) and t(m) are the final relative humidity and time of the experiment, respectively. M is humidifying constant used in the humidifying program. In the new programmed humidifying model, a linear relationship between the content function of drugs and the relative humidity is obtained, the degradation of drugs can be more uniform within different humidity ranges and the experimental results are more accurate than those in the reported linear humidifying model. The stability of penicillin potassium, as a solid state model, was investigated by the linear degradation programmed humidifying and the exponential heating experiments. The results indicated that the kinetic parameters obtained by the linear degradation programmed humidifying and the exponential heating models were significantly more precise than those obtained by the linear programmed humidifying and the reciprocal heating models.
authors.affiliation: Key Laboratory of Drug Targeting, West China School of Pharmacy, Sichuan University, Chengdu 610041, China.
authors.forename: Ning
authors.initials: N
authors.lastname: He
authors.forename: Xian-Cheng
authors.initials: XC
authors.lastname: Zhan
authors.forename: Lin-Li
authors.initials: LL
authors.lastname: Li
authors.forename: Bing
authors.initials: B
authors.lastname: Lin
authors.forename: Jian-Lin
authors.initials: JL
authors.lastname: Tao
authors.forename: Lu
authors.initials: L
authors.lastname: Jiang
mesh_terms: D004355:Drug Stability; D006813:Humidity; D007700:Kinetics; D008433:Mathematics; D008956:Models, Chemical; D010406:Penicillins / Q000737:chemistry*; D013678:Technology, Pharmaceutical / Q000379:methods*; D013696:Temperature
chemical_list: D010406:Penicillins