RESUMEN
The present study was conducted to evaluate the potential gastric protective and therapeutic effects of ranitidine mucoadhesive hydrogel formulae against ethanol induced gastric ulceration in rats. Adult female albino rats weighing between 200-220 g ,75 rats for evaluation of mucoadhesiveness of hydrogel and 70 rats for evaluation of protective and therapeutic effect of ranitidine hydrogel. The seventy rats were randomly divided into two experiments, protective and therapeutic effects of newly developed ranitidine mucoadhesive hydrogel formulae containing polymer mixture of Chitosan and Hydroxypropyl methyl cellulose [HPMC] at ratio 9:1 [F1] or mixture of Sodium carboxymethyl cellulose [NaCMC] and HPMC at ratio 9:1 [F2]. Each experiment has five groups, seven rats each; group 1 serves as control and group 2 serves as ulcer control since received a single oral dose of absolute ethanol [5ml/kg body weight]. Group 3 ulcer group received an oral dose of ranitidine [27mg/kg], while groups 4 and 5 ulcer group received newly formulae of ranitidine F1and F2 respectively. In the present study some gastric parameters as ulcer index, total acidity, gastric volume and pH besides some biochemical parameters as alanine aminotransferase [ALT], aspartate aminotransferase [AST] and total antioxidant capacity [TAC], total protein [TP] level and alkaline phosphatase [ALP] activity were carried out at the end of the experimental period.The present study showed that F1 revealed more protective and therapeutic potency than F2 as it was significantly reduced ulcer index, total acidity, gastric volume and pH in comparison to ulcerated group [p<0.05]. Also, the biochemical markers ALT, AST and TAC were decreased significantly compared to ulcerated group in both experiments. TP level and ALP activity were altered among different treatments. Moderate improvement in mucus secretion was recorded for F1 and F2 treatments than the reference drug. The present results were confirmed by the histopathology findings. Collectively, the current study confirmed the better therapeutic action of formulae 1 and 2 over the pure drug and that F1 was the most potent formula. Also, it encouraged the use of F2 as a curative agent of ulceration rather than a protective one