Salbutamol confirmation

Clinically, it has been confirmed that the drug is an effective bronchodilator with very little cardiovascular activity it does not appear to increase hypoxaemia [439]. A more detailed study [440], comparing salbutamol with isoprenaline and orciprenaline, demonstrated that 200 jug of salbutamol provided effective bronchodilation for at least three hours without detectable cardiac stimulation. Equivalent bronchodilator doses of isoprenaline and orciprenaline were 1000 /ag and 1500 jUg respectively. The bronchial effects of isoprenaline, though initially intense, waned within one hour and cardiac effects were noted. In this trial little objective difference could be detected between salbutamol and orciprenaline at the dose levels used, though most patients expressed preference for salbutamol. 

Three-level fractional factorial designs are also very useful, and charting the effects can be very helpful especially where there are more than three factors. The Plackett-Burman designs are often used to confirm (or otherwise ) the robustness of a method from the set value. Figure 17 shows some results from a ruggedness study for an HPLC method for salbutamol where the resolution factor, between it and its main degradation product is critical. 

Certain problems are peculiar to the use of wet nebuliza-tion inhalation devices. There is a risk of contamination of the airways with bacterial flora, which increases when treatment is given in a hospital (SEDA-2, 154). In one series of 41 patients in an intensive care unit who were being ventilated and were receiving nebulized salbutamol, all developed respiratory tract infections due to Burkholderia (Pseudomonas). The same organism (confirmed by molecular fingerprinting) was isolated from nebulizers and a multiple-dose bottle of salbutamol used for several of the patients. Appropriate infection control measures resolved the problem (SEDA-20,185). 

Inhalation of the intravenous formulation of tobramycin can cause bronchoconstriction, as has been confirmed in 26 children with mild to moderate cystic fibrosis (11). Nevertheless, while bronchoconstriction did occur, many patients did not have bronchoconstriction in response to the standard intravenous formulation. The risk of bronchoconstriction may further be reduced by pretreatment with salbutamol. 

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