Design and Optimization of Novel Taste-Masked Medicated Chocolates of Dextromethorphan with In vitro and In vivo Taste Evaluation

Purpose Dextromethorphan (DXM) is exceptionally bitter, yet the most widely used antitussive agents worldwide. It belongs to BCS class-II of pharmaceutical agents because of its poor water solubility; this is why it is only available in its hydrobromide salt form either in liquid or in solid formulations in the market. This water-soluble salt of the drug releases its content to a greater extent in salivary pH, which increases bitterness perception. This study aimed at designing a more palatable chocolate formulation of DXM, which releases the minimum drug in salivary pH. Methodology DXM nano-emulsion prepared using lecithin and Tween-80 was dried and incorporated in placebo chocolates, poured into silicon molds, and refrigerated to have medicated chocolates. Results Medicated chocolates had an average weight of 1.757 +/- 0.006 g, a thickness of 7.606 +/- 0.0175 mm, and hardness of 2.007 +/- 0.0102 Kp. The average drug content was 98.707 +/- 0.012%. The average particle size of optimized nano-emulsion was 101.145 +/- 2.906 nm with an encapsulation efficiency of 75.866 +/- 0.543%. Scanning electron microscopy (SEM) revealed the spherical structure of nanoparticles. Fourier transform infrared (FTIR) spectra and differential scanning calorimetry (DSC) thermograms showed no drug-excipient interaction, and X-ray diffraction (XRD) analysis confirmed the amorphous form of the drug in nano-emulsion. The minimal drug was released at salivary pH from chocolate formulation compared to the standard. The Human Panel taste evaluation confirmed better palatability of chocolate than marketed syrup and tablet formulations of DXM. Conclusion The novel medicated chocolate of DXM was proven to have a better palatability profile than its marketed formulations.