Article

The Influence of Liposomal Encapsulation on Sodium Cromoglycate Pharmacokinetics in Man

University of London; University of Wales College of Cardiff; Fisons plc
Pharmaceutical Research (Impact Factor: 4.74). 06/1989; 6(7):633-636. DOI: 10.1023/A:1015917918130

ABSTRACT The pharmacokinetics of pulmonary-administered sodium cromoglycate (SCG) has been studied in five healthy volunteers. SCG, 20 mg, was inhaled as a solution and encapsulated in dipalmitoyl phosphatidylcholine/cholesterol (1:1) liposomes. Liposomal SCG produced detectable drug levels in plasma from four volunteers taken 24 and 25 hr after inhalation. Inhaled SCG solution, although producing peak plasma levels more than sevenfold greater than liposomal drug, was not detectable in 24-hr samples from any volunteer. The decline in plasma levels following inhalation of liposomal SCG (reflecting the absorption phase) was best described by a biexponential equation. The two absorption rate constants differed by more than an order of magnitude. The rapid absorption phase was probably due to free or surface-adsorbed SCG in the liposomal formulation, since the absorption rate constant for this phase did not differ significantly from the absorption rate constant for SCG in solution. The phase of slow drug absorption may then be attributed to absorption of drug released from vesicles. The data indicate that encapsulation of SCG prior to pulmonary administration prolonged drug retention within the lungs and altered its pharmacokinetics.

0 Bookmarks
 · 
56 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Glucocorticoids (GC) are known for their potent immunosuppressive and anti-inflammatory properties. As a result, they are extensively used for the treatment of many different diseases. Prolonged and/or high-dose GC therapy, however, generally comes with severe side effects, resulting not only from their very diverse mechanism(s) of action, but also from their relatively poor biodistribution. Drug delivery systems, and in particular liposomes, have been extensively used to enhance the biodistribution and the target site accumulation of GC, and to thereby improve the balance between their efficacy and their toxicity. Many different types of liposomes have been employed, and both local and systemic treatments have been evaluated. We here summarize the progress made in the use of liposomal GC formulations for the treatment of asthma, rheumatoid arthritis, multiple sclerosis and cancer, and we show that the targeted delivery of GC to pathological sites holds significant clinical potential.
    Journal of Controlled Release 05/2014; · 7.63 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Microencapsulation of a number of drugs in microscopic phospholipid vesicles (liposomes) for site-targeted delivery of compounds is a novel area of drug delivery. More novel is the application of this concept for aerosol delivery of drugs to the lungs, particularly as it applies to the development of topical therapies for asthma. Although still in its relative infancy, pulmonary drug delivery of liposomal antiasthma drugs is a promising method of conferring sustained release and prolonged duration of action of drugs in the lung. It provides lung-targeted drug delivery with minimal systemic availability, thereby affording reduction in undesirable systemic adverse effects. The technology for delivery of liposomal antiasthma drugs as aqueous aerosols, metered dose inhalers and dry powder formulations for inhalation is evolving. This article provides an overview of various aspects of pulmonary delivery of a variety of liposomal antiasthma drugs.
    Clinical Immunotherapeutics. 11/1995; 4(5).
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A number of lipid-based technologies have been applied to pharmaceuticals to modify their drug release characteristics, and additionally, to improve the drug loading for poorly soluble drugs. These technologies, including solid-state lipid microparticles, many of which are porous in nature, liposomes, solid lipid nanoparticles and nanostructured lipid carriers are increasingly being developed for inhalation applications. This article provides a review of the rationale for the use of these technologies in the pulmonary delivery of drugs, and summarizes the manufacturing processes and their limitations, the in vitro and in vivo performance of these systems, the safety of these lipid-based systems in the lung, and their promise for commercialization.
    Advanced drug delivery reviews 05/2014; · 11.96 Impact Factor