A novel liquefied gas based oral controlled release drug delivery system for liquid drug formulations

• Published in: European journal of pharmaceutics and biopharmaceutics 2012-06, Vol.81 (2), p.334-338
• Main Authors: Haznar-Garbacz, Dorota, Garbacz, Grzegorz, Eisenächer, Friederike, Klein, Sandra, Weitschies, Werner
• Format: Article
• Language: English
• Subjects: Administration, Oral; Biological and medical sciences; Capillaries; Chemistry, Pharmaceutical - methods; Controlled delivery of liquids; Controlled delivery of semi-solids; Delayed-Action Preparations - administration & dosage; Delayed-Action Preparations - chemistry; Drug Delivery Systems - methods; Extended release; Gases - administration & dosage; Gases - chemistry; Gels; General pharmacology; Kinetics; Liquefied gas based drug delivery system; Medical sciences; Oral drug delivery system; Pentanes - administration & dosage; Pentanes - chemistry; Pharmaceutical technology. Pharmaceutical industry; Pharmacology. Drug treatments; Povidone - chemistry; Pressure; Rheology - methods; Solubility; Valproic Acid - administration & dosage; Valproic Acid - chemistry; Viscosity
• ISSN: 0939-6411; 1873-3441
• DOI: 10.1016/j.ejpb.2012.02.015

New approach for oral controlled delivery of liquids. A novel liquefied gas based drug delivery system for the oral delivery of liquid and semi-solid drug formulations is presented. The capsule-shaped system is equipped with a capillary as an element controlling the release rate. The delivery mechanism is based on a constant vapor pressure produced by isopentane as a low-boiling liquefied gas. The liquid drug valproic acid (VA) was used as a model compound. The viscosity was increased by the addition of povidone (PVP). The VA–PVP gel exhibited pseudoplastic rheological properties, the shear rate was above 0.1s−1, similar to a Newtonian liquid. The gels tested in the gas based delivery system provided near-zero-order release kinetics. The longest delivery time was up to ca. 8h. The system is characterized by high flexibility of the delivery rate, which can be achieved by adjusting system parameters such as the diameter and length of the capillary, the vapor pressure of the propellant and the viscosity of the drug formulation.