These are aqueous solutions that are instilled into the nose with a dropper. Nasal drops should be isotonic, having neutral pH and viscosity similar to nasal secretions. Use of oily vehicle is restricted, because it inhibits the movement of cilia in the nasal mucosa and if used for long periods, it reaches the lungs and causes lipoidal pneumonia. Nasal drops are dispensed in colored fluted bottles fitted with a dropper or in a suitable plastic container. The label should bear the indication “For external use only.” The drops are used to reduce the swelling of nasal mucosa and the underlying tissues. They reduce nasal congestion by retaining the solution within the nasal cavity. A nasal drop should have pH between 5.5 and 7.5, with mild buffer capacity, should be isotonic, should not modify the viscosity of mucus, should be compatible with ciliary movement and with medicament, should be inert, nontoxic and stable. Formulation of nasal drops requires vehicles such as purified water and liquid paraffin, tonicity-adjusting materials such as sodium chloride and dextrose, preservatives such as chlorobutanol and benzalkonium chloride and buffers such as phosphate buffer. Commonly incorporated medicaments in nasal drops include sympathomimetics, anti-inflammatory agents, adrenergic agents and decongestants

Example

Ephedrine nasal drops BPC

Chlorobutanol is dissolved in sufficient quantity of purified water. Ephedrine hydrochloride and sodium chloride are dissolved in purified water in a separate container. These two solutions are mixed together and the final volume is adjusted with purified water to make up the required volume.