fluticasone and norflurane

Current metered dose inhalers (MDIs) contain chlorofluorocarbon (CFC) propellants. A new propellant HFA134a, with no effect on ozone, may be a suitable alternative. Four asthma medications, salbutamol, salmeterol, fluticasone propionate (FP) and beclomethasone dipropionate (BDP), currently containing standard CFC propellants, were formulated with HFA134a for investigation. Single doses of salbutamol (200 micrograms) and salmeterol (50 micrograms, 100 micrograms) provided equivalent protection against bronchial provocation, after histamine and methacholine respectively, compared with the current preparation. A double-blind 4 week study comparing the two formulations of salbutamol, used as required in mild to moderate asthma, showed similar effects on morning peak expiratory flow rates (PEFR) and inhaler use. Salmeterol (50 micrograms) twice daily was compared with the current formulation in a 4 week trial. Improvement in morning PEFR was similar for both formulations. A double-blind study compared the two formulations of FP (250 micrograms) twice daily in moderate asthmatics previously taking 400-1,000 micrograms of inhaled corticosteroid daily. Morning PEFR improved in both groups. Safety and tolerability of the HFA134a product were similar to current formulations. The HFA134a formulations of salbutamol, salmeterol and FP provide equivalent efficacy with a similar safety profile to the existing formulations at equivalent doses.

Topics: Adult; Aerosol Propellants; Albuterol; Androstadienes; Anti-Inflammatory Agents; Asthma; Bronchodilator Agents; Child; Cross-Over Studies; Double-Blind Method; Fluticasone; Humans; Hydrocarbons, Fluorinated; Nebulizers and Vaporizers; Peak Expiratory Flow Rate; Salmeterol Xinafoate; Technology, Pharmaceutical

A new shadowgraphic imaging method and an associated instrument for analyzing the physical stability of pharmaceutical suspensions are introduced in this paper. The new suspension tester consists mainly of a high-resolution camera that takes sequential shadowgraphic images of emulsions or suspensions and a 2D collimated LED for simultaneous whole-sample illumination in bright field. A built-in ultrasonic bath provides controlled initial agitation to the samples of interest. Sequential images acquired by the experimental setup were used to derive normalized transmission profiles from which an instability index was developed for quantitative stability comparison between samples. Instrument performance was verified by measuring the stability of a series of oil-in-water emulsions prepared with surfactant mixtures of different ratios. The new instrument correctly determined the required hydrophilic-lipophilic balance for sunflower oil to be 7.0. The stability of a pressurized suspension of spray dried lipid (DSPC) particles was monitored for 5 days after propellant filling. Although stable for the first 24 h, the lipid suspension was found to decrease in stability from day 1 to day 4. Morphological and spectroscopic analysis revealed that the suspended DSPC particles had reformed into large thin sheets of lipid, thereby causing the gradual stability decrease during the aging study. The effects of initial agitation on the stability of suspensions were demonstrated by agitating a suspension of micronized fluticasone propionate in propellant using a wrist action shaker and an ultrasonic bath respectively. A significant improvement of suspension stability was achieved by replacing the wrist action shaker method with ultrasonic agitation. Simultaneous illumination of the complete suspension, a high image acquisition rate, and controlled initial agitation are features that make this new suspension tester a suitable and more reliable instrument for investigating the stability of pressurized pharmaceutical suspensions.

Topics: Aerosol Propellants; Drug Stability; Fluticasone; Hydrocarbons, Fluorinated; Image Interpretation, Computer-Assisted; Metered Dose Inhalers; Photography; Sunflower Oil; Surface-Active Agents; Suspensions; Technology, Pharmaceutical