FORMULATION OF COATED TABLETS OF DRY HAWTHORN EXTRACT AND THE DEVELOPMENT AND VALIDATION OF AN RP-HPLC METHOD FOR EVALUATING IT’S IN VITRO DISSOLUTION

Extracts of hawthorn (Crateagus sp.) have been indicated in the treatment of cardiovascular diseases, however, tablets produced from dry extract due to a multiple of factors such as inconsistent botanical ingredients, moisture content and hygroscopicity turn to be hard with prolong disintegration. Dissolution test is increasingly being employed for the assessment of solid herbal medicinal dosage form due to its ability to predict the bioavailability of active therapeutic agent from herbal products. The aim of this study was to formulate coated tablets containing dry extracts of hawthorn leafs and flowers and to develop and validate a reverse phase high performance liquid chromatography (RP-HPLC) method for assessing in vitro dissolution profile of hawthorn tablet. Comparative extraction procedure studies showed that percolating the plant material with ethanol and extracting with ethyl acetate produce extract with the highest amount of total flavonoids calculated either as rutin or hyperoside and the highest hyperoside content. Assessment of two disintegrating agents; Sodium starch glycolate (SSG) and cross-linked polyvinyl pyrrolidone (PVPP) showed that PVPP was a better agent for this formulation. Disintegration time also improved when distilled water was used as granulation fluid compared to alcoholic solutions. The disintegration time of coated tablets (CT), CT₁ and CT₂ were 8.83±0.41min and 9.33±0.52min respectively. The RP-HPLC method was validated as per ICH guidelines. The validation studies demonstrated that the proposed method is simple, selective, accurate and reliable and can be used for routine dissolution analyses of hawthorn tablets. The dissolution profile of the formulated tablets showed Q-values of 89.952% and 86.3765% for CT₁ and CT₂ respectively.