Physical Compatibility and Chemical Stability of Ketamine–Morphine Mixtures in Polypropylene Syringes
Bibliographic record
Abstract
BACKGROUND: Small amounts of ketamine administered with a narcotic can help to reduce both requirements for and potential adverse effects of the opioid. The use of ketamine in conjunction with morphine has become popular with the Acute Pain Service of the author's hospital. However, the only reported stability data that have been found for this combination stored in syringes were for 6 days at room temperature. OBJECTIVE: To conduct a compatibility and stability study with the ultimate aim of extending the current expiry date for the concentrations of ketamine and morphine combinations used at the author's institution and thus to allow batch production of mixtures of these drugs without increasing wastage. METHODS: Commercial solutions of ketamine (50 mg/mL) and morphine sulphate (50 mg/mL) were combined and further diluted with 0.9% sodium chloride to final concentrations of ketamine 2 mg/mL and morphine 2, 5, or 10 mg/mL; the resulting mixtures were packaged in polypropylene syringes. The syringes were stored at either 23°C or 5°C for 91 days. The following physical compatibility parameters were monitored: clarity, colour, and pH. Chemical stability was determined with a validated stability-indicating high-performance liquid chromatography system. RESULTS: Over the 91 days, all solutions remained clear and colourless, and the pH did not change significantly. The concentration of each drug in the various solutions remained above 98% of the original concentration for both storage conditions for the duration of the study. CONCLUSIONS: Solutions of ketamine (2 mg/mL) combined with morphine (2, 5, or 10 mg/mL) were physically compatible and chemically stable for 91 days when diluted with normal saline, packaged in polypropylene syringes, and stored at either 23°C or 5°C.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".