The number of animals used in research has increased with the advancement of research and development in medical technology. Every year, millions of experimental animals are used all over the world. The pain, distress and death experienced by the animals during scientific experiments have been a debating issue for a long time. Besides the major concern of ethics, there are few more disadvantages of animal experimentation like requirement of skilled manpower, time consuming protocols and high cost. Various alternatives to animal testing were proposed to overcome the drawbacks associated with animal experiments and avoid the unethical procedures. A strategy of 3 Rs (i.e. reduction, refinement and replacement) is being applied for laboratory use of animals. Different methods and alternative organisms are applied to implement this strategy. These methods provide an alternative means for the drug and chemical testing, up to some levels. A brief account of these alternatives and advantages associated is discussed in this review with examples. An integrated application of these approaches would give an insight into minimum use of animals in scientific experiments.

Mali et al.: Carboxymethyl cellulose-based hydrogel films for drug deliveryThe objective of this study was to synthesize and characterize citric acid crosslinked hydrogel films of carboxymethyl cellulose-tamarind gum for topical drug delivery. The hydrogel films were characterized by attenuated total reflectance-Fourier-transform infrared spectroscopy, solid-state 13 C-nuclear magnetic resonance spectroscopy and differential scanning calorimeter. The prepared hydrogel films were evaluated for the carboxyl content and equilibrium swelling ratio. Moxifloxacin hydrochloride was loaded into these hydrogel films and drug release was monitored in the phosphate buffer pH 7.4. Haemolysis assay was used to study biocompatibility of hydrogel films. Results of the attenuated total reflectance-Fourier-transform infrared spectroscopy, solid-state 13 C-nuclear magnetic resonance and differential scanning calorimeter confirmed the formation of citric acid-crosslinked hydrogel films. Total carboxyl content of hydrogel film was found to be increased when polymer ratio and amount of citric acid was increased. In contrast, swelling of hydrogel film was found to be decreased with increase in polymer ratio and amount of citric acid. Batch B1 showed highest drug loading with non-Fickian release mechanism. All remaining batches showed nonFickian release behavior with diffusion coefficient greater than 0.5. Results of haemolysis assay indicated that the citric acid crosslinked carboxymethyl cellulose-tamarind gum hydrogels were safe to be used in drug delivery. These results indicated that the citric acid crosslinked carboxymethyl cellulose-tamarind gum composite hydrogel film has the potential to be used in topical novel drug delivery systems.

Infections associated with the biofilms of

No abstract