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Abstract
Lactose is widely used as a carrier of drugs in inhalation devices for asthmatic patients, but some clinicans have suspected that it may cause bronchoconstriction. Only a few studies have been done to examine this and the results are not uniform. This study was conducted to determine the effects of inhalation grade lactose delivered by DiskhalerTMon lung function and airway conductance in asthmatic subjects. The effect of five doses of lactose ranging from 6·25 mg to 100 mg and placebo were investigated using spirometry and constant volume plethysmography. Nineteen subjects (nine females) with stable asthma and a proven reversibility of at least 12% in forced expiratory volume in 1 sec (FEV1) (compared to baseline) in the last 6 months, were included in this single-centre, randomized, placebo-controlled, double-blind, cross-over study. The subjects received placebo plus five doses of lactose on one study day and six doses of placebo on another study day. Both doses and study days were assigned in a random order, and intervals of 1 h were allowed between each dose and at least 36 h between study days. Specific airways conductance (sGaw) and FEV1were measured periodically over the course of 1 h after each dose of lactose or placebo. Administration of lactose at four or eight times the concentration in the DiskusTMand DiskhalerTMdry powder inhalers did not result in any statistically significant changes in FEV1. sGawalso showed no statistical difference between lactose and placebo at 1 or 3 min post-dosing. Both placebo and lactose produced both dilatation and constriction of the airways in the same patients, with no consistency in direction and no dose–response relationship. No adverse effect of lactose on airways conductance or FEV1of stable asthmatic patients was found in this study when given at higher than normal clinical doses.
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References
REFERENCES
- Generation of respirable clouds from coarse powder aggregates.J Biophar Sci. 1992; 3: 101-105
- Efficiency of aerosolization from dry powder blends of terbutaline sulfate and lactose with different particle size distribution.Pharm Res. 1990; 7: 81
- Drug delivery to the respiratory tract using dry powder inhalers.Int J Pharm. 1994; 101: 1-13
- Pulmonary deposition of99MTc-labelled salbutamol particles in healthy volunteers after inhalation from a metered-dose inhaler.Stp Phar Sci. 1994; 4: 29-32
- The use of different grades of lactose as a carrier for aerosolized salbutamol sulphate.Int J Pharmaceutics. 1999; 191: 1-14
- Drug carrier selection—important physicochemical characteristics.Proc Resp Drug Delivery. 1996; V: 103-113
- In vitro tolerability of human nasal mucosa: histopathological and scanning electron microscopic evaluation of nasal forms containing Sandostatin.Cell Biol Toxicol. 1995; 11: 295-301
- Bronchoconstriction due to inhaled lactose dry powder?.Eur Respir J. 1995; 8: 426s
- The effect of inhaled lactose on the airways in asthmatic subjects.Eur Respir J. 1995; 8: 204s
- Fine particle mass from the Diskus inhaler and Turbohaler inhaler in children with asthma.Eur Respir J. 1998; 11: 1111-1115
- Use of inhalation profiles from patients with severe obstructive lung disease using the DiskusTMinhaler and TurbohalerTMinhaler to evaluate device performance ex-vivo.Eur Respir J. 1997; 10: 258s
- Pulmonary deposition of lactose carriers used in inhalation powders.Int J Pharmaceutics. 2000; 196: 95-103
- Determination of the minimum dose of lactose drug carrier that can be sensed during inhalation.Br J Clin Pharmacol. 1995; 40: 281-282
- Fluticasone propionate powder: oral corticosteroid-sparing effect and improved lung-function and quality of life in patients with severe chronic asthma.J Allergy Clin Immunol. 1999; 103: 267-275
Article info
Publication history
Accepted:
June 13,
2001
Received:
December 28,
2000
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© 2001 Harcourt Publishers Ltd. Published by Elsevier Inc.
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