A comprehensive review on pharmaceutical uses of plant-derived biopolysaccharides.

Biopolysaccharides extracted from plants are mainly photosynthetic byproducts found in leaves, pods, stems, fruits, grains, seeds, corms, rhizomes, roots, bark exudates, and other plant parts. Recently, these plant-derived biopolysaccharides have received a great deal of attention as pharmaceutical excipients in a range of different dosage forms because of several key advantages, such as widespread accessibility from nature as plant-based sources are readily available, sustainable production, availability of easy and cost-effective extraction methodologies, aqueous solubility, swelling capability in the aqueous medium, non-toxicity, biodegradability, etc. The current review presents a comprehensive overview of the uses of plant-derived biopolysaccharides as effective pharmaceutical excipients in the formulations of different kinds of dosage forms, for example gels, pastes, films, emulsions, suspensions, capsules, tablets, nanoparticles, microparticles, beads, buccal formulations, transdermal formulations, ocular formulations, nasal formulations, etc.

Cefuroxime axetil loaded gastroretentive floating tabletsbased on hydrophilic polymers: preparation and in vitro evaluation

The aim of this work was to study the formulation and in vitro characterization of hydro dynamically balanced floating matrix tablets using Cefuroxime axetil (CA) as model drug. Different excipients such as hydroxy propyl methyl cellulose (HPMC) K15M, E5LV (gelling agent), sodium bicarbonate (gas generating agent) and sodium lauryl sulfate (SLS) (solubility enhancer) were used in order to optimize the drug release profile as well as floating property. Decrease in release characteristics with high viscous polymer were observed due to increased gel strength, tortuosity and length of drug diffusion path. Significant difference (p<0.5) in release rate was found at different concentration of SLS. The release mechanisms were explored and explained with zero order, first order, Higuchi, Korsmeyer and Hixson-Crowell equations. The release rate, extent and mechanism were governed by the content of polymer. The polymer content and amount of floating agent significantly affected the time required for 50%of drug release (t50%), mean dissolution time (MDT), release rate constant, and diffusion exponent (n).Kinetic modeling of dissolution profile revealed that the drug release mechanism could range from diffusion controlled to case II transport, which was co-dominated by diffusion polymer erosion in the release mechanism.

Formulation and in vitro characterization of xanthan gum-based sustained release matrix tables of isosorbide-5- mononitrate.

In the present investigation an attempt has been made to increase therapeutic efficacy, to reduce frequency of administration and to improve patient compliance by developing a sustained release matrix tablets of isosorbide-5-mononitrate. Sustained release matrix tablets of isosorbide-5-mononitrate were developed by using different drug: polymer ratios, such in F1 (1:0.75), F2 (1:1), F3 (1:1.5), F4 (1:1.75) and F6 (1:2). Xanthan gum was used as matrix former and microcrystalline cellulose as diluent. All the lubricated formulations were compressed, using 8mm flat faced punches. Compressed tablets were evaluated for uniformity of weight, content of active ingredient, friability, hardness, thickness, in vitro dissolution study using basket method and swelling index. Each formulation showed compliance with pharmacopoeial standards. Among all formulations, F5 showed a greater sustained release pattern of drug over a 12 h period with 92.12% of drug being released. The kinetic studies showed that drug release follows the Higuchi model (r(2) =0.9851). Korsemeyer and Peppas equation gave an n-value of 0.4566, which was close to 0.5, indicating that drug release follows the Fickian diffusion. Thus, xanthan gum can be used as an effective matrix former to extend the release of isosorbide-5-mononitrate. No significant difference was observed in the dissolution profile of optimized formulation, using basket and paddle apparatus.