Extended-release formulation of morphine for subcutaneous administration

Area of Science:

• Pharmacology
• Drug Delivery Systems
• Oncology

Background:

• Cancer pain management often requires narcotics with short half-lives, necessitating frequent injections or infusions.
• Current treatment methods for chronic cancer pain are associated with patient discomfort and inconvenience.
• There is a need for improved drug delivery systems for sustained narcotic release in pain management.

Purpose of the Study:

• To characterize an extended-release formulation of morphine sulfate (Depo/Morphine) using a lipid-based drug delivery system.
• To evaluate the in vitro and in vivo performance of Depo/Morphine in an animal model.
• To assess the potential of Depo/Morphine for managing chronic cancer pain and opioid addiction.

Main Methods:

• Lipid-based drug delivery system for extended-release morphine sulfate (Depo/Morphine) was developed.
• In vitro drug release half-life (T1/2) in human plasma at 37°C was determined.
• In vivo studies in an animal model assessed drug release kinetics and pharmacological effects following subcutaneous administration.

Main Results:

• Depo/Morphine demonstrated an in vitro release T1/2 of 12.1 days in human plasma.
• Subcutaneous administration of Depo/Morphine resulted in a prolonged T1/2 of morphine at the injection site (2.59 days) and in plasma (8.33 days) compared to unencapsulated morphine.
• Cataleptic behavior, a side effect of morphine, was not observed with Depo/Morphine, indicating improved tolerability.

Conclusions:

• Depo/Morphine is a promising extended-release formulation of morphine sulfate.
• This novel formulation has potential utility in managing chemotherapy-induced cancer pain.
• Depo/Morphine may also be beneficial for maintenance therapy in narcotic addiction treatment.