Non-Inhalation Sprays Formulation Development

Non-inhalation sprays include skin and mucous membrane sprays. Skin sprays mainly play the role of wound protection, cleaning and disinfection, local anesthesia and hemostasis. Sprays for vaginal mucosa are commonly used as O/W foam sprays, which are mainly used to treat vaginitis caused by microorganisms and parasites, and also for birth control. Besides, there are other types of non-inhalation sprays.

Advantages of Non-inhalation Sprays

• The drug can be delivered directly to the site of action or absorption, providing a very pronounced rapid-acting and localizing effect.
• The drug is encapsulated in a closed container, which can be kept clean and sterile, reducing the chance of contamination of the drug, and the residual drug after discontinuation is less likely to cause environmental pollution.
• Because the container is opaque, avoiding light and not in direct contact with oxygen and moisture in the air, it is conducive to improving the stability of the drug.
• The non-inhalation spray can reduce the irritation of the drug to the gastrointestinal tract and avoid the first-pass effect of the liver.

Quality Control Studies

Quality control of non-inhalation sprays requires, on the one hand, a comprehensive evaluation of the properties of the drug solution itself based on the raw materials and preparation process; on the other hand, it is necessary to pay attention to the investigation of the spray including spray angle, particle size distribution, mist flow rate, spray pattern and other properties to ensure the uniformity and stability of the formulation quality.

• The influence of the nature of the drug solution

The stability of drug formulations is inseparable from the physicochemical properties of the drug itself, such as drug solubility, permeability, pH, etc. These physicochemical properties also directly affect the prescription design of sprays.

• The influence of spraying device

As an important part of the spray, the spraying device not only determines the spray volume and number of sprays, but also has a direct impact on the spraying characteristics such as droplet shape and spray pattern. The particle size of the drug sprayed by the spraying device affects the uniform distribution of the drug in the mucous membrane.