Controlled Release Gastroretentive dosage form of

Abstract: The objective of the present investigation was to develop a gastroretentive tablets for verapamil hydrochloride (verapamil-HCl) using different hydrocolloid polymers including Carbopol (CP 934P; CP 940P), Hydroxypropylmethylcellulose (HPMC K4M; HPMC K15 M; HPMC E15) and Xanthan gum by direct compression technology. The tablets were evaluated for the physicochemical parameters such as weight variation, thickness, friability, hardness, drug content, in vitro buoyancy studies, swelling index study, in vitro dissolution studies. The prepared tablets exhibited satisfactory physico-chemical characteristics. Tablet bouncy was achieved by adding an effervescent mixture of sodium bicarbonate and anhydrous citric acid. The in vitro dissolution studies were carried out in a USP XXII apparatus 2 in 0.1N HCl. All the gastroretentive tablets showed good in-vitro buoyancy. The tablet swelled radially and axially during in-vitro buoyancy studies. The selected tablets (F6) containing Xanthan gum released approximately 97.89 % drug in 24 h in vitro dissolution study, while the buoyancy lag time was 24.6 ± 3.2 second and the tablet remained buoyant for> 24 h. Zero order and non-Fickian release transport was confirmed as the drug release mechanism for the selected tablets (F6). Tablets (F6) showed no significant change in physical appearance, drug content, total buoyancy time or in vitro dissolution study after storage at 45 °C/75 % RH for three months