Formulation of Fast-Dissolving Tablets of Promethazine Theoclate

Purpose: To optimize and formulate promethazine theoclate fast-dissolving tablets that offer a suitable approach to the treatment of nausea and vomiting.
Method: The solubility of promethazine theoclate was increased by formulating it as a fast-dissolving tablet containing β-cyclodextrin, crospovidone, and camphor, using direct compression method. A 3³ full factorial design was used to investigate the combined influence of three independent variables - amounts of camphor, crospovidone and β-cyclodextrin - on disintegration time, friability and drug release after 5 min.
Result: The optimization study, involving multiple regression analysis, revealed that optimum amounts of camphor, crospovidone and β-cyclodextrin gave a rapidly disintegrating/dissolving tablet. A checkpoint batch was also prepared to verify the validity of the evolved mathematical model. The optimized tablet should be prepared with an optimum amount of β-cyclodextrin (3.0 mg), camphor (3.29 mg) and crospovidone (2.61 mg) which disintegrated in 30 s, with a friability of 0.60 % and drug release of 89 % in 5 min.
Conclusion: The optimized approach aided both the formulation of fast-dissolving theoclate tablets and the understanding of the effect of formulation processing variables on the development of the formulation.

Keywords
Fast-dissolving tablet, 33 Factorial design, Promethazine theoclate, Optmization studies.