Gastroretentive Matrix Tablets of Boswellia Oleogum Resin: Preparation, Optimization, In Vitro Evaluation, and Cytoprotective Effect on Indomethacin-Induced Gastric Ulcer in Rabbits

Abstract

Abstract. Currently available anti-ulcer drugs suffer from serious side effects which limited their uses and prompted the need to search for a safe and efficient new anti-ulcer agent. Boswellia gum resin (BR) emerged as a safe, efficient, natural, and economic potential cytoprotective agent. Thus, it is of medical importance to develop gastroretentive (GR) formulations of BR to enhance its bioavailability and antiulcer efficacy. Early attempts involved the use of organic solvents and non-applicability to large-scale production. In this study, different tablet formulations were prepared by simple direct compression combining floating and bioadhesion mechanisms employing hydroxypropyl methylcellulose (HPMC), sodium carboxymethyl cellulose (SCMC), pectin (PC), and/or carbopol (CP) as bioadhesive polymers and sodium bicarbonate (SB) as a gas former. The prepared tablets were subjected for assessment of swelling, floating, bioadhesion, and drug release in 0.1 N HCl. The optimized GR formulation was examined for its protective effect on the gastric ulcer induced by indomethacin in albino rabbits compared with lactose tablets. The obtained results disclosed that swelling, floating, bioadhesion, and drug release of the GR tablets of BR depend mainly on the nature of the matrix and the ratio of polymer combinations. Moreover, a combination of SCMC-CP in a ratio of 2:1 (SCP21) exhibited desirable floating, bioadhesion, swelling, and extended drug release. Also, a 6-h pretreatment with SCP21 tablets decreased the severity of inflammation and number of bleeding spots among ulcer-induced rabbits in comparison to those treated with lactose tablets.

Polymeric micelles for potentiated antiulcer and anticancer activities of naringin

“…Paul's index as an integral indicator of the number of lesions induced per treatment group and antiulcer activity (AA) were estimated to evaluate the cytoprotective activity of naringin against ulcer. [51][52][53] Paul's index was calculated by multiplying the mean number of ulcers and the percentage of rats with ulcers to be then divided by 100. As well, AA was calculated by dividing Paul's index of the positive control group (II) by that of each of the treatment groups.…”

“…The AA was recognized if AA was at least of two units. [51][52][53] Hence, the cytoprotective activity (AA.2) of naringin against ethanol-induced ulcer in rat model has been enhanced on micellization with PF68 allowing lowering in dose compared with free drug. This enhancement can be referred to more prolonged residence time and selective accumulation of nanomicelles in ulcerative tissues.…”

Colon Targeting of Naringin for Cytoprotection against Ulcerative Colitis: In Vitro-In Vivo Study

“…The same process was followed in PB pH 6.8 and 7.4 using the same tablet. The mean weights of tablets were determined after repeating the process twice to calculate the percent swelling according to the following relation [2,20]:…”

“…The oral route is commonly used to administer drugs because of better patient compliance, easier administration and relatively lower production cost than other routes [1,2]. Site-specific delivery systems for targeting drugs to the colon have been widely investigated during the last decade.…”

Investigation and Evaluation of an <i>in Situ</i> Interpolymer Complex of Carbopol with Polyvinylpyrrolidone as a Matrix for Gastroretentive Tablets of Ranitidine Hydrochloride

“…12) Since that, combined gastroretentive mechanisms were employed to enhance gastroretention including floating and bioadhesive approaches. 13,14) Bioadhesive polymers can be used to add bioadhesiveness to the floating systems in order to extend their GRT and counteract their premature gastric emptying. Commonly used bioadhesive polymers are polyacrylic acid (PAA) and its lightly crosslinked commercial forms, carbopol (CP), that exhibited strong bioadhesive properties and also appeared to be biocompatible.…”