Long-term stability of morphine and bupivacaine mixture for spinal use

From clinical studies it has been proven that morphine in combination with bupivacaine is applicable in cancer pain. The availability of a ready to us e parental dosage form of morphine and bupivacaine is comfortable for healt h care workers. Stability of a morphine or a bupivacaine preparation or a c ombination of both in a PVC cassette or polypropylene syringe for spinal us e is examined in several studies. Apart from one study no data on long-term stability of morphine-bupivacaine mixture is available. A forced degradation study and a shelf-life study at room temperature (20-2 5 degrees C) were started on morphine hydrochloride 0.2 mg/ml and bupivacai ne hydrochloride 7.5 mg/ml in 50 ml sterilized glass bottles type II. The r esults of the stability study showed that this mixture was stable up to 18 months at room temperature, whereafter morphine showed a slight degradation (5 %) and bupivacaine remained stable.