Dear Editor:

The results of this study showed Dynapar quick penetrating solution (QPS) Plus is safe and provides faster and more than six times higher skin penetration of diclofenac in comparison to marketed diclofenac aerosol spray. Due to the faster and higher penetration of diclofenac from Dynapar QPS Plus, it is the most suitable option to treat pain and inflammation related to acute as well as chronic musculoskeletal disorders [1]. We applaud the author’s conclusion on the study. Nevertheless, we believe the outcome needs to be discussed in a few more aspects to understand it better.

Firstly, the study was a randomized, open-label, two-treatment, two-period, two-sequence, single-dose, balanced, crossover, comparative bioavailability study [2]. However, cross-over study details are not available. Randomization allocation and sequence allocation are not mentioned.

Lastly, the sample size of 8 for the quoted study is too small, and the method of calculation is not clear. So, the result cannot be generalized to the whole population. Determining the sample size is an important step in the process of designing clinical research. It is imperative to comprehend that various study designs necessitate distinct approaches for estimating sample size [3]. We welcome the author’s response in these aspects, which will help the medical community understand the effects of Dynapar QPS Plus is better.

No potential conflict of interest relevant to this article was reported.