Sodium alginate

Colon targeted drug delivery system is capable of protecting the drug in route to the colon i.e. drug gets released and absorbed once it reaches the colon. A multiparticulate system combining pH sensitive property and biodegradability has been investigated to prepare and evaluate Eudragit S-100 coated Sodium alginate microspheres for colon targeting of Tramadol Hydrochloride. Uncoated Tramadol Hydrochloride microspheres were prepared by ionotropic gelation technique using different ratios of Tramadol Hydrochloride and Sodium alginate. Coated Tramadol Hydrochloride microspheres were prepared by coacervation phase separation technique using different ratios of uncoated Tramadol Hydrochloride and Eudragit S-100/ Eudragit L-100. Uncoated and coated Tramadol Hydrochloride microspheres were evaluated for percentage yield, particle size, surface morphology, flow properties, drug content and entrapment efficiency and were found to be within the acceptable range. The uncoated microspheres sustained the release upto 8 hrs whereas coated microspheres sustained the release upto 12 hrs in a pH progression medium mimicking the condition of GIT. The drug release from MC4 formulation coated with Eudragit S-100 (1:4) showed desired rate as there was no drug release observed upto 4-5 hrs, while in colonic fluid controlled drug release was observed releasing about 69.66 % after 12 hrs. The release kinetics followed Peppas showing Super Case II transport. Stability studies suggested formulations were stable. It is concluded from the present investigation that Eudragit S-100 coated Sodium alginate microspheres are promising controlled release carriers for colon targeted delivery of Tramadol Hydrochloride.

In this paper an attempt is made to prepare IPN beads of the drug by taking alginate solution in combination with a polymer (PVA/Kennel powder /Guar gum). The prepared copolymer solution is dropped in to 2% CaCl2. The beads are hardened by cross linking with a common cross-linking agent, glutaraldehyde. The beads are characterized by Fourier transform infra-red spectroscopy and scanning electron microscopy. Additionally quality control tests such as swelling index, bead water uptake, entrapment efficiency and drug release studies are performed. The extent of cross-linking is studied in terms of the size and release characteristics of the beads. Most of the formulations indicated erosion based release pattern. The size of the beads ranged from 250 to 400 µm. The entrapment efficiency of the formulation ranged from 73.6% to 94.50%.  

The aceclofenac sodium loaded calcium alginate (CA) based microbeads prepared by ionotropic external gelation technique with calcium chloride as cross-linking agent. Calcium alginate microbeads represent a useful tool for oral sustained/ controlled drug delivery but show several problems, mainly related to the stability, and rapid drug release at higher pH that, in most cases, is too fast due to increase porosity. To overcome such inconveniences, which was to develop CA microbeads coated with xyloglucan (XG) as drug release modifier to improve stability and prolong the drug release. The mean particle sizes of drug-loaded microbeads were found to be in the range 476.45±12 to 765.10 ± 0.22. The drug entrapment efficiency was obtained in the range of 62.24±0.66 to 102.75 ± 0.87.The shape and surface characteristics were determined by scanning electron microscopy (SEM). No significant drug-polymer interactions, physical changes and crystallinity of the drug in the formulations were determined by FT-IR spectroscopy, differential scanning calorimetry (DSC) and X-ray powder diffraction [XPRD]. In-vitro drug release profiles of microbeads were pH dependent and were analyzed by different kinetic models. The mechanism of drug release from microbeads depends on swelling and erosion process resulting CA microbeads was diffusion controlled followed by First order kinetics and whereas CA microbeads coated with XG approaching to near Zero- order kinetics.

The aim of present investigation was to develop press coated tablet for pulsatile drug delivery of lornoxicam using hydrophilic and hydrophobic polymers. The drug delivery system was designed to deliver the drug at such a time when it could be most needful to patient of rheumatoid arthritis. The press coated tablets containing lornoxicam in the inner core was formulated with an outer shell by different weight ratio of hydrophobic polymer (ethyl cellulose) and hydrophilic polymers (sodium alginate). The release profile of press coated tablet exhibited a lag time followed by burst release, in which outer shell ruptured into two halves. The effect of formulation composition on the barrier layer comprising both hydrophobic and hydrophilic excipients on the lag time of drug release was investigated. It was observed that lag time decreases with increasing concentration of sodium alginate. The optimized formulation (F5) comprised 10: 90%w/w concentration ratio of sodium alginate: Ethocel 10 cps with a 245 mg coating weight, and showed a desired lag time of 308 minutes, which mimics the fluctuating symptoms of rheumatoid arthritis, followed by rapid release of lornoxicam.