[A basic study on usefulness of bleomycin incorporated in poly DL-lactic acid]

Area of Science:

• Biomaterials Science
• Pharmacology
• Drug Delivery Systems

Background:

• Poly DL-lactic acid (PLA) is a biodegradable polymer with potential applications in drug delivery.
• Developing novel drug formulations is crucial for effective cancer treatment.
• Bleomycin (BLM) is an anti-cancer drug requiring controlled release mechanisms.

Purpose of the Study:

• To develop and evaluate a new dosage form of bleomycin (BLM) using Poly DL-lactic acid (PLA) blends.
• To assess the in vitro dissolution profile of BLM from the BLM-PLA formulation.
• To investigate the in vivo distribution and BLM activity following subcutaneous implantation of BLM-PLA in rats.

Main Methods:

• Preparation of BLM-PLA composite cylinders.
• In vitro dissolution testing of BLM-PLA in saline.
• Subcutaneous implantation of BLM-PLA in rats and subsequent measurement of BLM activity in various tissues (connective tissue, lymph node, lung, liver, kidney) over 35 days.

Main Results:

• In vitro, BLM dissolution from BLM-PLA reached 49.2% at 7 days, 85.2% at 14 days, and 99.7% at 21 days.
• In vivo, high BLM concentrations were sustained in connective tissues for 14 days and in lymph nodes for 21-28 days.
• Low BLM levels were observed in the lung, liver, and kidney, indicating localized drug action.

Conclusions:

• PLA serves as an effective carrier for a drug delivery system.
• The BLM-PLA formulation demonstrates potential as an effective anti-cancer modality, particularly for local chemotherapy.
• The localized drug delivery minimizes systemic exposure, suggesting improved therapeutic index.