Studies on indomethacin intraocular implants using different <i> in vitro</i> release methods

Intra ocular implants of sodium alginate alone and in combination with hydroxypropylmethylcellulose with or without calcium chloride were formulated with indomethacin as a model drug. The drug release from the implants was evaluated using static method, continuous flow through apparatus (developed in house), USP dissolution and agar diffusion. Except in the static method, indomethacin particle size did not impart any effect on the drug release. In agar diffusion method, an increase in agar concentration from 1 to 2% resulted in a significant decrease (P< 0.005) in the amount of drug released. Inclusion of hydroxypropylmethylcellulose (33.3, 41.6 and 50% w/w), resulted in decrease of indomethacin release irrespective of the method of dissolution study. The agar diffusion method and the continuous flow through methods seem to simulate to a certain extent the in vivo conditions as far as the placement of the device and the hydrodynamic diffusion layer around the intra ocular implant is concerned. The static method and USP method affected the hydrodynamic diffusion layer either too slowly or too fast

Microsponges: a promising frontier for prolonged release-current perspectives and patents

Abstract Background Microsponges are one of the advanced drug delivery systems that facilitates precise and controlled release of active ingredients that are suitable for topical and oral use. These porous microspheres are typically sized between 5 and 300 μm, offer benefits including controlled release, stability, and minimized side effects. Manufacturing techniques like quasi-emulsion solvent diffusion and liquid–liquid suspension polymerization are usually employed to prepare microsponges, although various challenges arise from the use of potentially hazardous organic solvents. Main body Microsponges possess distinct traits such as extended drug release, formulation flexibility, and high drug loading capacity. Entrapment of drugs requires considerations of solubility, stability, and miscibility, while evaluation methods encompass production yield and particle size analysis. Their applications range from dermatological to biopharmaceutical delivery, with diverse products utilizing this technology. Ongoing innovations about microsponges are evident in patents concerning medical dressings and hyaluronic acid delivery systems. Conclusion Microsponges present a promising avenue in drug delivery, despite many challenges. Current review addresses on limitations and diverse products highlighting commercial viability. Patent activity signifies continued interest, suggesting significant potential for enhancing patient care

Development and Evaluation of pH-Dependent Micro Beads for Colon Targeting

The purpose of this research was to develop and evaluate multiparticulates of alginate and chitosan hydrogel beads exploiting pH sensitive property for colon-targeted delivery of theophylline. Alginate and chitosan beads were prepared by ionotropic gelation method followed by enteric coating with Eudragit S100. All formulations were evaluated for particle size, encapsulation efficiency, swellability and in vitro drug release.In vitro dissolution studies performed following pH progression method demonstrated that the drug release from coated beads depends on coat weights applied and pH of dissolution media. Mechanism of drug release was found to be swelling and erosion-dependent. The studies showed that formulated alginate and chitosan beads can be used effectively for the delivery of drug to colon and a coat weight of 20% weight gain was sufficient to impart an excellent gastro resistant property to the beads for effective release of drug at higher pH values

Ionic Cross-linked Chitosan Beads for Extended Release of Ciprofloxacin: In vitro Characterization

Chitosan beads loaded with ciprofloxacin hydrochloride were fabricated by ionic cross-linking with sodium tripolyphosphate. The beads showed an excellent water retention property. The degradation of fabricated beads was influenced by the pH of test medium. High drug load was achieved within the bead with a short curing time. Drug release was high in acidic medium (pH 1.2) vis-à-vis intestinal medium (pH 7.4). Ciprofloxacin hydrochloride release increased with an increasing concentration of ciprofloxacin and decreasing proportion of chitosan. Drug release followed both first-order and Higuchi's root time kinetics showing non-Fickian release mechanism

Development and evaluation of microbial degradation dependent compression coated secnidazole tablets for colonic delivery

The present paper describes development of a polysaccharide based compression coated tablets of secnidazole for colon delivery. Core tablet containing secnidazole was compression coated with various proportions of guar gum, xanthan gum and chitosan, either alone or in combinations. Drug release studies were performed in simulated gastric fluid (SGF) for 2 h followed by simulated intestinal fluid (SIF, pH 7.4) up to 24 h. Secnidazole release from the prepared formulations was dependent on the type and concentration of polymer used in the formulation. Tablets coating containing either guar gum or xanthan gum showed ~30-40% drug release in 8 h. Further, in vitro dissolution studies of selected formulations performed in the dissolution media with rat caecal contents showed 54.48±0.24 - 60.42±0.16% of drug release. Formulations with single polymer in coating layer were unsuitable for targeting secnidazole release to colon region. Combination of chitosan with guar gum or xanthan gum exhibited control over secnidazole release