Influence of iontophoresis on delivery of NSAID-loaded deformable liposomal dispersions: in vitro and in vivo evaluation.

Aim: Negatively charged deformable liposomes (DL) of ketoprofen were formulated to enhance transdermal delivery of ketoprofen (KP) under the influence of iontophoresis for intraarticular delivery. Methods: Conventional and deformable KP liposomes were prepared using thin film hydration, characterized and intraarticular delivery of KP was evaluated using Sprague-Dawley rats. Results: Vesicles displayed entrapment efficiency (>71%); zeta potential <-25 mV; size between 152.4 ± 12.42 nm to 220.4 ± 6.22 nm, KP-DL were stable under iontophoresis. Conventional and deformable liposomes exhibited relatively higher iontophoretic flux values than passive flux; Iontophoretic delivery enhanced KP availability in the synovial fluid (1.34 ± 0.12 µg.h/ml) fourfold over passive delivery (0.329 ± 0.15 µg.h/ml). Conclusion: Iontophoretic mediated transport of deformable liposomes could improve transdermal delivery of ketoprofen into the synovial joints than conventional liposomes.

The present work is testing the effect of current on the movement of a drug. The name of the drug is ketoprofen (KP). To prepare small-size particles of KP, a new preparation called as deformable liposomes is used. These liposomes were prepared using solvents to dissolve drugs and fats. Later the solvents were removed to form a thin film. Further to the thin film, a water-based solvent was added to form minute particle dispersed in water. The suspension was tested to find out the size, charge and amount of drug gone into it. More than 70% of KP was included and surface charge was negative and size was very less. Amount of KP entering inside the bone joints on the knee showed that four-times higher amount moved inside with the help of current than without the help of current (passive). So, with the help of current, higher amount of drug could be transported to decrease pain.

Thermosensitive in situ liposomal gels loaded with antimicrobial agent for oral care in critically ill patients.

Aim: A novel thermosensitive in situ gel loaded with meropenem (MP) liposomes was designed to improve retention in the oral cavity as a prophylactic measure to prevent ventilator-acquired pneumonia in critically ill patients. Methodology & results: Meropenem liposomes were incorporated into poloxamer 407 gels and gamma irradiated. Mean size of liposome was 247 nm, polydispersity index < 0.3 and zeta potential >-25 mV; properties remained unaltered even post sterilization. Permeation study revealed that 75.26% and 34% of MPs were released from MP in situ gel and MP in situ liposomal gel, respectively. The relation between viscosity (cp) and shear rate (1/s) indicate that in situ gels exhibited non-Newtonian behavior at 37°C. The study using Pseudomonas aeruginosa confirmed the antimicrobial activity of meropenem. Conclusion: Prolonged in situ residence, because of rapid gelation process enables an easy administration of meropenem as liposomal suspension in critically ill patients.

Effect of gamma sterilization on the properties of microneedle array transdermal patch system.

Soluble microneedles (MNs) of four different hydrophilic polymers namely sodium carboxymethyl cellulose (CMC), polyvinylpyrrolidone (PVP) K30, PVP K90 and sodium hyaluronate (HU) were fabricated by mold casting technique. When exposed to gamma radiation, a dose of 25 kilogray (kGy) was found to render the microneedle (MN) sterile. However, CMC was found to form MNs with poor mechanical properties, whereas PVP K30 MNs were drastically deformed upon exposure to applied dose as observed in bright field microscopy. Scanning electron microscopy (SEM) revealed that morphology of PVP K90 and HU MNs were not significantly affected at the applied dose. The appearances of characteristic peaks of irradiated MNs of PVP K90 and HU in Fourier-transform infrared spectra suggested structural integrity of the polymers on irradiation. Differential scanning calorimetry (DSC) indicated gamma irradiation failed to alter the glass transition temperature and thus mechanical properties of PVP K90 MNs. However, DSC and Powder X-ray Diffraction (PXRD) conclusively indicated that the degree in crystallinity of HU was substantially reduced on irradiation. In vitro dissolution profiles of sterile PVP K90 and HU MNs were similar to un-irradiated MNs with a similarity factor (f2) of 64 and 54, respectively. In vivo dissolution studies in human subjects indicated that sterile MNs of PVP K90 and HU exhibited dissolution of 78.45 ± 1.09 and 78.57 ± 0.70%, respectively, after 20 min. The studies suggested that PVP K90 and HU could be suitable polymers to fabricate soluble MNs as the structural, morphological, microstructural and dissolution properties remained unaltered post γ sterilization.

Design and statistical optimization of glipizide loaded lipospheres using response surface methodology.

A 32 factorial design was employed to produce glipizide lipospheres by the emulsification phase separation technique using paraffin wax and stearic acid as retardants. The effect of critical formulation variables, namely levels of paraffin wax (X1) and proportion of stearic acid in the wax (X2) on geometric mean diameter (dg), percent encapsulation efficiency (% EE), release at the end of 12 h (rel12) and time taken for 50% of drug release (t50), were evaluated using the F-test. Mathematical models containing only the significant terms were generated for each response parameter using the multiple linear regression analysis (MLRA) and analysis of variance (ANOVA). Both formulation variables studied exerted a significant influence (p < 0.05) on the response parameters. Numerical optimization using the desirability approach was employed to develop an optimized formulation by setting constraints on the dependent and independent variables. The experimental values of dg, % EE, rel12 and t50 values for the optimized formulation were found to be 57.54 +/- 1.38 mum, 86.28 +/- 1.32%, 77.23 +/- 2.78% and 5.60 +/- 0.32 h, respectively, which were in close agreement with those predicted by the mathematical models. The drug release from lipospheres followed first-order kinetics and was characterized by the Higuchi diffusion model. The optimized liposphere formulation developed was found to produce sustained anti-diabetic activity following oral administration in rats.