Relative bioavailability of sodium cromoglycate to the lung following inhalation, using urinary excretion

Abstract

The urinary excretion of sodium cromoglycate in the first 0.5 h post inhalation can be used to compare the relative lung deposition of two inhaled products or of the same product using different inhalation techniques. This represents the relative bioavailability of sodium cromoglycate to the lung following inhalation. Similar 24 h urinary excretion of sodium cromoglycate can be use to compare the total dose delivered to the body from two different inhalation products/inhalation methods. This represents the relative bioavailability of sodium cromoglycate to the body following inhalation. Because of the lack of difference between the INH and INHC in the first 0.5 h, the use of activated charcoal is not necessary when this method is used to compare the relative lung bioavailability of different products or techniques.

Relative Lung Bioavailability of Generic Sodium Cromoglycate Inhalers Used With and Without A Spacer Device

“…previously reported for salbutamol, 16 sodium cromoglycate 9 and nedocromil sodium 17 is useful to compare different inhalation methods and products. At present, DISCUSSION work is in progress to show the use of this technique for other drugs.…”

“…A comlungs and body following inhalation has been rebination of a breath-actuated inhaler with a small ported. 9 The amounts of sodium cromoglycate recovered in the urine sample taken 30 min post-start of an inhalation has been shown to be an index of the relative amounts of drug deposited in the …”

“…Table 1 shows that there was were sigcromoglycate delivered to the systemic circulation nificant differences in the urinary SCG excreted, post-inhalation is via the pulmonary rather than the 30 min and 0-24 h post inhalation, following MDI, oral route. 9 The 24 h urinary excretion of sodium MDI+VOL, EB and EB+O administration.…”

“…Measurement of the 24 h urinary recovery of sodium cromoglycate post-inhalation allows an estimate of the relative total systemic bioavailability of the inhaled dose. 9 In this study, the relative bioavailability of sodium cromoglycate to the lungs and body has been determined following inhalation of 20 mg sodium cromoglycate from different inhaled products. The inhaled products evaluated are the generic Cromogen …”

Assessment of recent nebulizer delivery systems using urinary pharmacokinetics method and aerodynamic characteristics of TOBI ® nebulized dose following inhalation

“…Therefore, in these cases, urine provides useful PK data following inhalation [36,37]. It has been successfully employed in the determination of the relative lung bioavailability of many inhaled drugs, such as salbutamol [38], sodium cromoglycate [39], nedocromil sodium [40], inhaled gentamicin [41,42] and inhaled tobramycin [43].…”