Counterpain PXM Versus Diclofenac Versus Piroxicam

The primary goal is to demonstrate that a gel containing the active ingredients Piroxicam plus Counterirritant is equally effective and safe as two other widely used gels in reducing pain. The three gels being compared are:

1. Test Gel: Piroxicam plus Counterirritant (brand name Counterpain® PXM). This gel combines an anti-inflammatory drug (Piroxicam) with ingredients that create a distinct warming or cooling sensation on the skin (methyl salicylate, eugenol, and menthol). 2. Comparator Gel A: Piroxicam gel only (brand name Pirofel®). This gel contains the anti-inflammatory drug Piroxicam by itself. 3. Comparator Gel B: Diclofenac gel (brand name Hotin® DCL). This is another very common and well-studied anti-inflammatory gel, often considered a standard treatment for this type of pain.

The study's central hypothesis is that the Piroxicam-plus-counterirritant gel is not inferior to the other two and provides a similar level of pain relief and safety. This type of study is called an equivalence trial.

How is the Study Designed?

This is a Phase 3, Randomized, Controlled, Multi-center, Single-blind, Parallel-group study. Here's what each of these terms means: * Phase 3: This is a confirmatory stage of research, often done after a product is already on the market, to confirm its effectiveness and safety in a larger group of people compared to standard treatments. * Randomized: Participants will be assigned to one of the three gel groups purely by chance, using a computer-generated list (like flipping a coin). This randomization is the best way to ensure the three groups are comparable at the start of the study, minimizing bias in the final results. * Controlled: The test gel (Piroxicam plus Counterirritant) is being compared against two "control" groups who are using other known and accepted treatments (Piroxicam-only and Diclofenac gels). * Multi-center: The study will take place at two different clinic locations: Klinik Utama Eminence and St. Carolus Sports Clinic by Eminence. This helps in recruiting enough participants and makes the results more generalizable to the wider population. * Single-blind: In this type of study, the participants do not know which gel they are using. To achieve this, all the original gel tubes will be completely covered with a plain white sticker, hiding their brand identity. They will only have a study label with a unique code. This prevents the participants' expectations (e.g., thinking a particular brand works better) from influencing how they report their pain. The doctors and physiotherapists who assess the participants will also not know which gel corresponds to which code, ensuring their evaluations are objective. Only the study coordinator and the principal investigator will have access to the master list that links the codes to the actual gels. * Parallel-group: This means that each participant will only use one type of gel for the entire duration of the study. They will not switch to another gel.