Analysis of corticosteroid formulations in metered dose inhalers

Researchers have proposed a “promising” UV spectroscopic approach for quantifying both formoterol and beclomethasone formulations in pressurised metered dose inhalers. The team worked to develop an analytical method that is “viable and user-friendly”. 

Musale et al. acknowledged that there are analytical techniques for assessing formoterol fumarate and beclomethasone dipropionate in combination dry powder inhalers.

However, the study presented in the paper focused on developing and validating a UV spectrophotometric method for quantifying the corticosteroid in pressurised metered dose inhalers. The authors remarked that the analytical method has a key role in “ensuring the quality, safety, and efficacy of inhalation therapies for the management of respiratory conditions”.

Results from the investigation

In determining the concentration of beclometasone and formoterol in the 6+200 mcg/spray inhaler formulation, the researchers concluded that the test method facilitated “desirable characteristics of linearity, precision, and accuracy”.

With the estimation performed at a wavelength of 240nm for beclomethasone dipropionate and 216nm for formoterol fumarate, additional findings from the research showed:

• Satisfactory linearity within the concentration range was observed for both drugs. This was found to be 10-30 μg/ml for beclomethasone dipropionate and 0.3 to 0.9 μg/ml for formoterol fumarate at wavelengths of 240 nm (r^2=0.999) and 216 nm (r^2=0.999), respectively.
• The Beer-Lambert law was adhered to within the concentration range of 10-30 μg/ml for beclomethasone dipropionate and 0.3-0.9 μg/ml for formoterol fumarate.

Efficient formulation analysis

Musale et al. clarified that the analytical method enabled no interference from any excipients present in the product formulation during analysis of the drugs. As such, this further validates the method’s specificity, according to the authors.

While the proposed methods are subjected to validation following ICH guidelines. However, once validated, Musale et al. concluded that the analytical method investigated in the study could be used for efficient “simultaneous determination of beclomethasone dipropionate and formoterol fumarate in routine analytical applications, offering a rapid and reliable solution for pharmaceutical analysis in the field”.

The paper was published in the International Journal of Current Science Research and Review.