AIMTo study the influence of light and heat on the stability of procaine hydrochloride injection.

METHODSAccelerated tests upon exposure to light at high temperatures were employed.

RESULTSIn experiments with either isothermal heating or exposure to light at high temperatures, the drug degradation rate obeys first-order kinetics. The total rate constant, ktotal, caused by both light and heat can be divided into two parts: ktotal = kdark + klight, where kdark and klight are the rate constants caused by heat and light, respectively. The klight can be expressed as klight = Alight x E x exp(-Ea,light/RT). Where E is the illuminance of light, Alight is an experimental constant related to light sources, and Ea,light is an experimental constant.

CONCLUSIONBecause the form of klight is similar to the Arrhenius equation, it is suggested that Ea,light might be the observed activation energy of the rate-determining step of the subsequent processes of the photochemical reaction. This viewpoint is supported by the fact that the Ea,light is independent of light sources.

Drug Stability ; Hot Temperature ; Injections ; Light ; Mathematics ; Procaine ; administration & dosage ; chemistry ; radiation effects

To expand the donor pool, organ donation after cardiac death (DCD) has emerged. However, kidneys from DCD donors have a period of long warm ischemia between cardiac arrest and the harvesting of the organs. Recently, we used extracorporeal membrane oxygenation (ECMO) to minimize ischemic injury during 'no touch' periods in a Maastricht category II DCD donor and performed two successful kidney transplantations. The kidneys were procured from a 49-yr-old male donor. The warm ischemia time was 31 min, and the time of maintained circulation using ECMO was 7 hr 55 min. The cold ischemia time was 9 hr 15 min. The kidneys were transplanted into two recipients and functioned immediately after reperfusion. The grafts showed excellent function at one and three months post-transplantation; serum creatinine (SCr) levels were 1.0 mg/dL and 0.8 mg/dL and the estimated glomerular filtration rates (eGFR) were 63 mL/min/1.73 m2 and 78 mL/min/1.73 m2 in the first recipient, and SCr levels were 1.1 mg/dL and 1.0 mg/dL and eGFR were 56 mL/min/1.73 m2 and 64 mL/min/1.73 m2 in the second recipient. In conclusion, it is suggested that kidney transplantation from a category II DCD donor assisted by ECMO is a reasonable modality for expanding donor pool.
Adult ; *Death ; *Extracorporeal Membrane Oxygenation ; Female ; Glomerular Filtration Rate ; Glucose/chemistry ; Humans ; *Kidney Transplantation ; Male ; Mannitol/chemistry ; Middle Aged ; *Organ Preservation ; Potassium Chloride/chemistry ; Procaine/chemistry ; Retrospective Studies ; Time Factors ; Tissue Donors

OBJECTIVE: To develop a specific, sensitive, reproducible SPE-HPLC method for the determination of 37 drugs in whole blood. METHODS: With the doxapram as internal standard, Oasis column was used to extract drugs from whole blood. Two kinds of mobile phases were used in this study. Separations were achieved by a LiChrospher 100 RP-C18 (250 mm x 4.0 mm x 5 microm) column kept at 50 degrees C, the DAD detector was set at 230 nm and 250 nm. RESULTS: The limit of detection were 1-30 ng/mL. The method showed excellent linearity and the linear correlation coefficient was > or =0.997 98. The relative standard deviation for between-day and within-day assay were <10%. CONCLUSION The method is effective, simple, reliable and has been used in real cases.
Chromatography, High Pressure Liquid/methods* ; Doxapram/isolation & purification* ; Doxepin/isolation & purification* ; Estazolam/isolation & purification* ; Forensic Medicine ; Humans ; Morphine/isolation & purification* ; Papaverine/isolation & purification* ; Pharmaceutical Preparations/isolation & purification* ; Prazosin/isolation & purification* ; Procaine/isolation & purification* ; Reproducibility of Results ; Sensitivity and Specificity ; Solid Phase Extraction/methods* ; Solvents/chemistry*