Formulation and in-vitro Evaluation of Carvedilol Gastroretentive Capsule as (Superporous Hydrogel)

The preferred route of drug administration is the oral route, but drugs with narrow absorption window in the gastrointestinal tract are still challenging. The ability to extend and monitor the gastric emptying time is a valuable tool for processes remaining in the stomach longer than other traditional dosage forms. The purpose of this study was to formulate and evaluate gastroretentive superporous hydrogel (SPH) of carvedilol with view to improve its solubility and increase gastric residence time in order to get sustained release formulas via utilization of various kinds and concentrations of hydrophilic polymers then after, incorporate the best prepared formula into capsules. Sixteenth formulae of SPH hybrid were prepared by gas blowing technique from the following materials; monomers (Poly vinyl alcohol, and Acrylamide), cross-linkers (Methylene bisacrylamide, and glutaraldehyde), hybrid agent (Chitosan), foaming agent (NaHCO3) and foam stabilizer (Tween 80). Different amounts or concentrations of these materials were utilized to investigate their effect on SPH properties (density, porosity, floating, drug content, drug release, swelling time, and swelling ratio). The soaking procedure was utilized for loading of carvedilol into SPH hybrid (6.25mg/2.5g SPH). After analysis the results statistically and application the similarity factor (f2) equation, formula F8 was selected as the best formula and incorporated into capsules. The drug release data were applied to different mathematical kinetics and the results were shown to be fitted to Higuchi model and the release mechanism was (non fickian) diffusion. The overall results suggested that the proposed SPH hybrid drug delivery system is encouraging for carvedilol specific delivery to the stomach.

Formulation, Characterization and Antihelminthic Activity Testing of Nitazoxanide Superporous Hydrogel Tablets

In the pharmaceutical field controlled release products have the ability to maintain desired medicament concentration or a longer period of time. Certain drugs are relatively insoluble in water and have high dose requirements that render unsuitable formulation difficulties in sustained release formulations. Nitazoxanide which is a high dose water insoluble antiprotozoal drug was formulated with the aim. To modulate gastro-retentive dosage form based on the superporous hydrogel composites. Foaming technique was used in the preparation of SPH composites. The superporous hydrogels were extremely sensitive to pH of swelling media and good porosity. Superporous hydrogels tablets of nitazoxanide showed good pre-compressional and post-compressional properties. Formulation X is the best formulation containing chitosan, polyvinyl alcohol, formaldehyde, exhibited good swelling ratio. The compatibility studies were performed by Fourier Transform Infrared (FT-IR) Spectroscopic Studies, Differential Scanning Calorimetry Studies (DSC). All formulations were evaluated for stability, drug content, and kinetic drug release & in-vitro drug release profile. It was concluded that the proposed gastro-retention drug delivery provides a different supply of nitazoxanide directly to the stomach. Keywords: Nitazoxanide, Anti protozoal, foaming technique, Chitosan

Cu(ii)-alginate-based superporous hydrogel catalyst for click chemistry azide–alkyne cycloaddition type reactions in water

The Cu(ii)-alginate-based superporous hydrogel was prepared and used as a heterogenous catalyst in the regioselective click of 1,4-disubstituted-1,2,3-triazoles by CuAAC reactions.

EFFECT OF CELLULOSIC POLYMER ON PHYSICO MECHANICAL PROPERTIES OF SUPERPOROUS HYDROGEL OF AN ANTIHYPERTENSIVE DRUG AND DRUG RELEASE KINETICS FROM IT

Objective: Super porous hydrogels (SPHs), a novel drug delivery system can be developed to retain drugs in the gastric medium. The aim of the present investigation was to prepare superporous hydrogels (SPHs) of Atenolol to release the drug in sustained manner in the gastric environment and study the effect of two grades of hydroxyl methyl cellulose along with Carbopol 971p on the physico mechanical properties and drug release kinetics of the formulations. Methods: Superporous hydrogels of Atenolol were prepared with two grades of Hydroxy Propyl Methyl Cellulose (HPMC K100M and HPMC K15 M) along with Carbopol 971p the structural morphology of hydrogel was observed by Scanning Electron Microscopy. Study on Physico mechanical characteristics and drug release were done. Results: Scanning Electron microscopy studies of the formulations revealed the presence of large number of pores in different size ranges like 1 µm, 2 µm, 10 µm, confirming the formulations as superporous hydrogel. A correlation had been found between porosity, density and % swelling index. The drug release data from the formulations obeyed Higuchi and Korsmeyer-Peppas kinetics. Further, the data were fitted to the Kopcha model for confirming drug release by a combination of diffusion-controlled and chain relaxation–swelling mechanism. Conclusion: Among the six formulations, where HPMC K15 M and HPMC K100 M both were present, the gel became more hydrophobic and retarded the release of drug. From the drug release kinetics data, it can be concluded that the diffusion mechanism predominated the drug release process, leading to quasi diffusion and Fickian diffusion mechanism.