Each actuation delivers:
Salbutamol Sulphate IP equivalent to Salbutamol IP â¦â¦.100 mcg
Suspended in propellant 134aâ¦â¦â¦â¦q.s.
Salbutamol is a selective beta2-adrenoreceptor agonist. At therapeutic doses, it acts on the beta2-adrenoceptors of bronchial smooth muscle, with little or no action on the beta1-adrenoceptors of the cardiac muscle. Salbutamol provides short-acting (4-6 hours) bronchodilation with a fast onset (within 5 minutes) in reversible airways obstruction.
Salbutamol administered intravenously has a half-life of 4-6 hours and is cleared partly renally and partly by metabolism to the inactive 4'-O-sulphate (phenolic sulphate), which is also excreted primarily in the urine. The faeces are a minor route of excretion.
After administration by the inhaled route, between 10% and 20% of the dose reaches the lower airways. The remainder is retained in the delivery system or is deposited in the oropharynx from where it is swallowed. The fraction deposited in the airways is absorbed into the pulmonary tissues and circulation, but is not metabolized by the lungs. On reaching the systemic circulation, it becomes accessible to hepatic metabolism and is excreted, primarily in the urine, as unchanged drug and as phenolic sulphate.
The swallowed portion of an inhaled dose is absorbed from the gastrointestinal tract and undergoes considerable first-pass metabolism to phenolic sulphate. Both unchanged drug and conjugate are excreted primarily in the urine. Most of a dose of salbutamol given intravenously, orally, or by inhalation is excreted within 72 hours. Salbutamol is bound to plasma proteins to the extent of 10%.
ASTHALIN Inhaler â¦â¦â¦â¦..Canister containing 200 metered doses