[Physico-chemical stability and sterility of non-opioid analgesics in solution]

Intravenous patient-controlled analgesia: in vitro stability profiles of mixtures containing fentanyl, hydromorphone, oxycodone, nefopam, ondansetron, and ramosetron

Background and objectives

Patient-controlled analgesia often involves combinations of multiple drugs. This study aimed to determine the stability of drug mixtures commonly used for intravenous patient-controlled analgesia.

Materials and methods

We examined four of the most commonly used drug combinations in intravenous patient-controlled analgesia at our institution. Mixtures contained fentanyl (400 μg), either oxycodone (10 mg) or hydromorphone (4 mg), nefopam (20 mg), and either ondansetron (10 mg) or ramosetron (0.3 mg). Each drug mixture was diluted in 0.9% saline and stored in a portable patient-controlled analgesia system at room temperature (24 °C) for 96 h. Physical attributes including color, turbidity, and precipitation were assessed using digital imaging and optical microscopy. Sterility testing was conducted to assess for microbiological contamination. The pH of each mixture was monitored for up to 96 h after mixing. The concentration of each drug in the mixture was also evaluated using high-performance liquid chromatography.

Results

All mixtures remained colorless and transparent with no visible sediment for 96 h. After 14 days of culture, none of the samples showed bacterial or fungal growth. The pH for all mixtures was maintained between 4.17 and 5.19, and the mean pH change in any mixture was less than 0.4 over the study period. The concentration of each drug remained between 90 and 110% of the initial value for 96 h after mixing.

Conclusion

Four drug mixtures commonly used for intravenous patient-controlled analgesia are physiochemically stable and remain sterile for 96 h after mixing.

Physicochemical stability of binary admixtures of paracetamol and dexketoprofen-trometamol for patient-controlled analgesia use

Background

Intravenous admixtures of dexketoprofen-trometamol and paracetamol are frequently used in clinical practice due to synergism obtained administering both drugs concomitantly. Physicochemical stability of binary admixture containing both drugs is currently unknown.

Objective

To determine physicochemical stability of binary admixture containing dexketoprofen-trometamol 50 mg and paracetamol 1000 mg in a low-density polyethylene bottle at different storage conditions of light and temperature for advanced preparation.

Methods

Eight mixtures containing dexketoprofen-trometamol (Enantyum ampule 2 mL) 50 mg and paracetamol (Paracetamol B. Braun bottle 100 mL) 1000 mg were prepared and stored at: room temperature and exposed to light; room temperature and protected from light; refrigerated and exposed to light; and refrigerated and protected from light. From each mixture, aliquots were extracted at different times for 15 days. For physical compatibility, pH measure, gravimetric analysis and visual inspection were carried out. For chemical stability, concentrations of dexketoprofen-trometamol and paracetamol were simultaneously measured by high performance liquid chromatography.

Results

Only refrigerated mixtures showed incompatibility since white precipitation appeared at day 6, possibly due to paracetamol instability. Remaining drugs concentrations were in all cases≥90% after 15 days.

Conclusion

Binary mixture containing paracetamol (100 mL) 1000 mg and dexketoprofen-trometamol (2 mL) 50 mg in a low-density polyethylene bottle is physicochemically stable for 5 days under refrigeration and 15 days at room temperature. By considering also microbial contamination, this mixture can be prepared in advance, 5 days stored refrigerated and 2 days stored at room temperature, being unnecessary protection from light.

[Stability and compatibility of acetaminophen, ketoprofen and amoxicillin in a fail-safe intravenous administration set]

OBJECTIVES

Intravenous infusion takes an important place in the current therapy in hospitals and pharmaceutical firms keep improving their infusion medical devices, particularly with the development of an intravenous administration set with an automatic infusion stop. The aim of our study consists in an evaluation of the stability of acetaminophen, ketoprofen and amoxicillin during infusion and stasis of drugs for several hours in the dropper chamber and in the tube of this device.

STUDY DESIGN

Analytical study.

MATERIALS AND METHODS

Ten milligram per millilitre acetaminophen (acetaminophen 1 and acetaminophen 2), 1 mg/mL ketoprofen and 20 mg/mL amoxicillin were prepared and infused individually and successively with the intravenous administration set under ambient light and temperature. Collected samples of each drug during the infusion and after 24 hours of stasis in the medical device were monitored by a visual inspection, pH and osmolality assessment and chromatographic analysis of each drug with a validated stability-indicating method.

RESULTS

Repeated individual perfusions of 10 mg/mL acetaminophen 1 or 1 mg/mL ketoprofen are possible through a fail-safe intravenous administration set, while repeated individual amoxicillin infusions are not because of the unstability of this drug. There is also no problem to infuse successively acetaminophen and ketoprofen through this medical device because these drugs are stable. However, we underlined an incompatibility between acetaminophen 2 and ketoprofen, which advises against the use of intravenous administration set for successive infusions of these two drugs.

CONCLUSION

Despite the technical innovation of a fail-safe intravenous administration set, we have to stay aware of mixture consequences in intravenous infusion field.