Pulmonary agents stability

Some pulmonary agents are stored and shipped as concentrated solutions to facilitate handling and stabilize the agents. Odors will vary depending on the characteristics of the solvent(s) used and concentration of pulmonary agent in the solution. 

Dixon and Mountain reported that exposure of mice to ozone at 1 ppm for 5 h resulted in a depletion of lung histamine content to as low as 75% of the control value 5 days later. They also observed that pretreatment with promethazine, an antihistaminic agent, resulted in a decrease in the amount of pulmonary edema produced by a sublethal dose of ozone. However, promethazine, in addition to being a potent antihistaminic agent, is a phenothiazine derivative and thus might act to trap fiee radicals or stabilize membranes. 

If a (3-adrenoceptor antagonist is administered prior to sufficient ol-radrenoceptor blockade, a hypertensive episode may be precipitated with cardiac failure and pulmonary oedema. Most intravenous anaesthetic agents have been used safely, but ketamine is contraindicated. Sodium nitroprusside can be used to achieve arteriolar dilation. Esmolol, a pi-selective antagonist with very short duration of action, is administered intravenously to prevent cardiac arrhythmias intra-operatively. After tumour removal, volume administration should be aggressive to maintain haemodynamic stability, and a noradrenaline infusion may be required. 

As it becomes increasingly probable that delivery of drugs as aerosols can be achieved readily, the focus can shift to the nature of the therapeutic agent and its physical and chemical stability in the required dosage forms. New chemical entities can be considered for delivery to the lungs to facilitate the control of pulmonary diseases or diseases that may be treated by pulmonary drug delivery. 

Taplin GV, Chopra SK (1978) Limg perfusion-inhalation scintigraphy in obstructive airway disease and pulmonary embolism. Radiol Clin N Am 16 491-513 Tofe AJ, Bevan JA, Fawzi MB, Francis MD, Silberstein EB, Alexander GA, Gimderson DE, Blair K (1980) Gentisic acid a new stabilizer for low tin skeletal imaging agents. Concise commimica-tion. J Nucl Med 21 366-370... 

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