Stability and Sterility of Extemporaneously Prepared Nonpreserved Cefazolin, Ceftazidime, Vancomycin, Amphotericin B, and Methylprednisolone Eye Drops.

PURPOSE: To determine in-use stability and sterility of fortified cefazolin, ceftazidime, vancomycin, amphotericin B, and methylprednisolone eye drops in a simulated inpatient setting with and without a mobile refrigerated container (MR). METHODS: Each drug was prepared and divided into 4 groups: 1) simulated patient use with the MR group: stored at 4°C and kept in the MR during drug administration, 2) simulated patient use without the MR (NoMR) group: stored at 4°C and no MR, 3) refrigerated control group: stored at 4°C, and 4) room temperature control group: stored at room temperature. Stability and sterility data were evaluated at days 0, 4, 7, 14, 21, and 28. Linear mixed-effects model and survival analysis were performed. RESULTS: Median time to 10% loss of concentration for in-use medications (MR/NoMR groups) was >28/27.9, 22.2/22.2, 19.4/19.4, 10.18/<4, and >28/>28 days for cefazolin, ceftazidime, vancomycin, amphotericin B, and methylprednisolone, respectively. There was no significant difference in the predicted concentration loss per day among all groups for vancomycin and methylprednisolone (all P > 0.05). For the other study medications, all room temperature control groups, the cefazolin NoMR group, and the ceftazidime NoMR group had significantly greater predicted concentration loss per day compared with the refrigerated control groups (all P ≤ 0.02). Culture results were negative for all drugs throughout the study. CONCLUSIONS: The NoMR group showed that the drug significantly degraded rapidly for cefazolin, ceftazidime, and amphotericin B. Implementation of MR could decrease the predicted loss of concentration per day for cefazolin and ceftazidime. In vitro antimicrobial activity and sterility were retained for 28 days.

Pharmacokinetic of gabapentin 600 mg tablet in Thai healthy subjects.

BACKGROUND: Gabapentin is an antiepileptic drug. It is structurally similar to yaminobutyric acid (GABA), which crosses the blood-brain barrier. Gabapentin is absorbed into the blood by the L-amino acid transport system. The oral bioavailability of gabapentin displays dose-dependence. Plasma concentrations ofgabapentin are not directly proportional to dose. Therefore, pharmacokinetic of gabapentin is essential for patients who have to receive gabapentin 600 mg. OBJECTIVE: To investigate the pharmacokinetic of gabapentin 600 mg in Thai healthy subjects. MATERIAL AND METHOD: The present study was performed on 24 healthy Thai male subjects who received a single oral dose of 600 mg gabapentin tablet. Serial blood samples were collected before and to 48 hours after drug administration. Plasma gabapentin concentrations were determined by automated High Performance Liquid Chromatography (HPLC) with UV detector after deproteinized with acetonitrile followed by derivatization with 1-fluoro-2,4-dinitrobenzene. The relevant pharmacokinetic parameters were determined. RESULTS: The mean values of pharmacokinetic parameters (mean +/- SD) were 3.17 +/- 0.80 hour (1.5 to 5.0 hour) for T; 4,853.58 +/- 1,369.67 ng/ml for Cm; 0.11 +/- 0.02 hour for Kel, 6.62 +/- 1.87 hour (4.89 to 11.41 hour) for T1/2; 47,712.88 +/- 12,853.61 ng.hour/ml for AUC0-t, 48,713.20 +/- 12,909.78 ng.hour/ml for AUC0-inf, 5.24 +/- 1.32 L/hour for CI, and 49.28 +/- 15.98 L for Vd. CONCLUSION: The data show the pharmacokinetic parameters of gabapentin 600 mg. These data should be used to support the assignment of therapeutic purposes for patients who have to receive gabapentin 600 mg.