Formulation and in vitro-in vivo evaluation of buccoadhesive morphine sulfate tablets.

Buccoadhesive controlled-release systems for the delivery of morphine sulfate were prepared by compression of hydroxypropyl methylcellulose (HPMC) with carbomer (CP), which served as the bioactive adhesive compound. The release behavior of systems containing 30 mg of morphine sulfate and various amounts of the two polymers was found to be non-Fickian. The adhesion force was significantly affected by the mixing ratio of HPMC and CP in the tablet, and the weakest adhesion force was observed at a ratio of 1:1 (HPMC:CP). Interpolymer complex formation was confirmed between HPMC and CP in acidic medium by turbidity, viscosity, and FT-IR measurements. The amount absorbed (percentage of the drug loaded) of the controlled-release buccoadhesive tablets in six healthy volunteers and was 30 +/- 5%.

Physico-chemical and bioadhesive properties of polyacrylic acid polymers.

In this study, influence of several physico-chemical properties of bioadhesive polyacrylic acid poylmers (Carbopol 910, Polycarbophil, Carbopol 940 and Carbopol 934 PH) are investigated. The effect of pH on the swelling of polyacrylic acid polymers was studied at constant temperature, ionic strength and osmolality. The polymers showed the pH dependence of equilibrium swelling. The bioadhesive strength of the bond formed between surface-preswollen systems and the sublingual bovine mucus was determined by tensile experiments. It was found that the least substituted polymers Polycarbophil and Carbopol 910 with low molecular weight showed the same degree of bioadhesion while highly branched polyacrylic acid polymers Carbopol 940 and 934 PH showed reduced bioadhesion.