Hydrogels are the three-dimensional network structures obtained from a class of synthetic or natural polymers which can absorb and retain a significant amount of water. Hydrogels are one of the most studied classes of polymer-based controlled drug release. These have attracted considerable attention in biochemical and biomedical fields because of their characteristics, such as swelling in aqueous medium, biocompatibility, pH and temperature sensitivity or sensitivity towards other stimuli, which can be utilized for their controlled zero-order release. The hydrogels are expected to explore new generation of self-regulated delivery system having a wide array of desirable properties. This review highlights the exciting opportunities and challenges in the area of hydrogels. Here, we review different literatures on stimuli-sensitive hydrogels, such as role of temperature, electric potential, pH and ionic strength to control the release of drug from hydrogels.

The present study aimed to develop a kinetically stable nanoemulsion of artemether with improved solubility, stability and oral bioavailability. Nanoemulsion was prepared by ultrasonication technique using internal oil phase (consisted of the drug dissolved in coconut oil and span 80) and external phase (comprising tween 80 and ethanol dissolved in water). The formulations were optimized using various parameters like percentage transmittance, refractive index, drug content, viscosity, zeta potential and release rate. Stability studies were conducted for a period of 90 days using stability chambers. In vivo studies of the developed formulations were conducted on Wistar rats and data were analyzed statistically. The nanoemulsion as observed under transmission electron microscope were found to be spherical in shape with an average size of 79.0 nm and a zeta potential of -15 mV which indicated of good electrokinetic stability of nanoemulsion . Nanoemulsion was found to be clear and transparent in appearance with a percentage transmittance of 98.2. Refractive index of 1.32 of the nanoemulsion indicated the isotropic nature of the drug. Release rate of the drug from the nanoemulsion formulation was found to be quite significant (P < 0.001) as compared to the plain drug. In vivo oral bioavailability of the nanoemulsion formulation was found to be 2.6-fold higher than the plain drug (˜ 40%) as observed from pharmacokinetic studies. Thus it was observed that nanoemulsion proved itself as a promising alternate for improving the bioavailability of artemether.

The present study aimed to develop lipid-polymer hybrid nanoparticles (LPNs) for the combined pulmonary delivery of isoniazid (INH) and ciprofloxacin hydrochloride (CIP HCl). Drug-loaded LPNs were prepared by the double-emulsification solvent evaporation method using the three-factor three-level Box-Behnken design. The optimized formulation had a size of 111.81 ± 1.2 nm, PDI of 0.189 ± 1.4, and PDE of 63.64 ± 2.12% for INH-loaded LPN, and a size of 172.23 ± 2.31 nm, PDI of 0.169 ± 1.23, and PDE of 68.49 ± 2.54% for CIP HCl-loaded LPN. Drug release was found to be sustained and controlled at lower pH and followed the Peppas model. The in vitro uptake study in alveolar macrophage (AM) showed that uptake of the drugs was increased significantly if administered in the form of LPN. The stability study proved the applications of adding PLGA in LPN as the polymeric core, which leads to a much more stable product as compared to other novel drug delivery systems. Spray drying was done to produce an inhalable, dry, powdered form of drug-loaded LPN. The spray-dried (SD) powder was equally capable of producing nano-aggregates having morphology, density, flowability and reconstitutibility in the range ideal for inhaled drug delivery. The nano aggregates produced by spray drying manifested their aerosolization efficiency in terms of the higher emitted dose and fine particle fraction with lower mass median aerodynamic diameter. The in vivo study using pharmacokinetic and pharmacodynamic approaches revealed that maximum internalization efficiency was achieved by delivering LPN in SD powdered forms by pulmonary route.

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Impact of organizational culture (strong and weak) and use of influence tactics (soft and hard) on transformational leadership was studied using a 2 × 2 experimental design and a sample of 120 executives in a large manufacturing firm in eastern India. Results of analyses of variance show that leaders are seen as more transformational if the organizational culture is strong rather than weak, and if leaders use soft influence tactics rather than hard tactics. Transformational leadership is the highest when soft tactics are used in a strong culture, and the lowest when hard tactics are used in a weak culture.