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Relative lung and systemic bioavailability of sodium cromoglycate inhaled products using urinary drug excretion post inhalation
Author(s) -
Aswania Osama,
Chrystyn Henry
Publication year - 2002
Publication title -
biopharmaceutics and drug disposition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.419
H-Index - 58
eISSN - 1099-081X
pISSN - 0142-2782
DOI - 10.1002/bdd.308
Subject(s) - inhalation , bioavailability , urine , metered dose inhaler , pharmacokinetics , excretion , dry powder inhaler , pharmacology , chemistry , sodium cromoglycate , sodium , inhaler , medicine , chromatography , anesthesia , asthma , organic chemistry
The relative lung and systemic bioavailability of sodium cromoglycate following inhalation by different methods have been determined using a urinary excretion pharmacokinetic method. On three separate randomised study days, 7 days apart, subjects inhaled (i) 4×5 mg from an Intal ® metered dose inhaler (MDI), (ii) 4×5 mg from an MDI attached to a large volume spacer (MDI+SP) and (iii) 20 mg from an Intal Spinhaler ® (DPI). Urine samples were provided at 0, 0.5, 1, 2, 5 and 24 h post dose. The mean (S.D.) amount of sodium cromoglycate excreted in the urine during the first 30 min post inhalation was 38.1 (27.5), 222.3 (120.3) and 133.1 (92.2) μg following MDI, MDI+SP and DPI, respectively. The mean ratio (90% confidence interval) of these amounts excreted in the urine over the first 30 min for MDI+SP vs MDI, DPI vs MDI and MDI+SP vs DPI was 801.0 (358.0, 1244; p <0.002)%, 457.0 (244.0, 670.0; p <0.02)% and 262.4 (110.2, 414.5)%, respectively. Similarly for the 24 h cumulative amount of sodium cromoglycate excreted over the 24 h post inhalation the ratios were 375.4 (232.9, 517.9; p <0.005)%, 287.5 (183.4, 391.6; p <0.02)% and 211.4 (88.3, 334.5)%, respectively. The results highlight better lung deposition of sodium cromoglycate from a metered dose inhaler attached to a large volume spacer. Copyright © 2002 John Wiley & Sons, Ltd.