A 3 2 factorial design was used to develop Natamycin cubosome nanoparticles with enhanced corneal permeation, so as to effectively treat ocular fungal keratitis. Probe sonication technique was deployed to disperse the dry lipidic film to obtain colloidal dispersion. The colloidal dispersion was characterized for critical quality attributes such as particle size, poly dispersibility index (PDI), zeta potential and entrapment efficiency. The optimized batch exhibited a particle size of 158.2 nm, zeta potential-40 mV, PDI 0.328 in addition, entrapment efficiency of 99.85%. The in vitro drug release of natamycin from optimized cubosome demonstrated a cumulative %drug release of 84.29% at the end of 8 hours. The optimized cubosomal dispersion exhibited enhanced in vitro antifungal activity against Candida albicans and Aspergillus fumigatus as compared to a pure drug suspension. The optimized formulation was further analyzed for polarized light microscopy (PLM), transmission electron microscopy (TEM) and small angle Xray scattering (SAXS) to state the morphology of formed cubosome nanoparticles and was noted to be Im3m bicontinous cubic mesophasic structure. X-ray diffraction (XRD) studies affirmed the complete encapsulation of natamycin into cubosome vesicles. Ex vivo corneal permeation studies of optimized formulation revealed enhanced corneal permeation in comparison to a pure drug suspension. The ocular irritation studies performed on rabbits indicated the cubosome to be non-irritant. Finally, the developed natamycin cubosome nanoparticles demonstrated sustained drug release and increased corneal penetration. Thus, these cubosome nanocarriers present a propitious delivery system for effective management of ocular fungal keratitis.

Background and Aims: Invasive pulmonary aspergillosis (IPA) is an imperative concern in the present era due to its high occurrence and mortality rate in severely immunocompromised patients. The present study was designed to develop, optimize and characterize encapsulated nystatin (NYS) cubosome nanoparticles as an inhalable system, a viable alternative for effective management of IPA. Methods: A dry lipidic film comprising glycerol monooleate (GMO), Span 83, Poloxamer (P-407) and dispersed NYS was subjected to ultrasound sonication to produce colloidal dispersion of cubosomes. The process and formulation variables were screened using Plackett Burman design and further optimized by Box Behnken design by evaluating its effect on particle size, polydispersity index (PDI), zeta potential and entrapment efficiency. Results: The optimized NYS cubosomes were nearly spherical with some irregular polyangular symmetry as visualized by transmission electron microscopy (TEM). Further, small angle X-ray scattering (SAXS) affirmed Pn3m cubic mesophasic structure. The optimized nanoparticles had particle size 263.5 nm, zeta potential -14.4 mV, PDI 0.283 and entrapment efficiency 82%. The in-vitro cytotoxicity assay indicated that NYS cubosomes reduced cell cytotoxicity in contrast to pure drug post 48h. In-vitro haemolytic assay denoted lower toxicity of formulation as compared to free drug. In-vitro drug release studies highlighted, slow but continuous release from NYS cubosomes until 48h and showcased Higuchi release kinetics. Likewise, NYS cubosome demonstrated higher antifungal activity compared to drug suspended in phosphate buffer. Conclusion: Thus, non-invasive feature and contemplated target specificity of nystatin loaded cubosome nanoparticles pave a mode for its prospect as pulmonary delivery to combat IPA.

No abstract

Objective: The aim of the study was to develop and validate a bioanalytical reverse-phase high-performance liquid chromatographic (HPLC) method for the estimation of nystatin in rat plasma after intranasal administration. Methods: The reversed-phase HPLC system was equipped with a Luna C18 column, the mobile system comprised of methanol, water, and dimethylformamide (55:30:15) and the flow rate was set at 0.9 ml/min. Results: The elution time for nystatin was 4.096±0.025 min. The calibration curves constructed in rat plasma were linear from 0.25 to 50 μg/ml. The lower limit of quantification (LOQ) was found to be 0.25 μg/ml. The standards for accuracy and precision of the intra- and inter-day variation studies were in the acceptable ranges as per the FDA guidelines. Conclusion: The LOQ value determined by the proposed method was noted to be satisfactory for inspecting the plasma pharmacokinetics of nystatin in rats’ post-administration of a nasal in situ gelling liquid crystalline precursor formulation in an in vivo study.

Objective: The impact of incorporating a polar aprotic solvent, dimethyl sulfoxide (DMSO) to glycerol monooleate (GMO)/ oleic acid (OA) system was evaluated briefly, on purpose to map its influence on gel microstructure and dynamic phase transition in controlling performance of polyene antifungal drug delivery system. Methods: An in-situ gelling fluid precursor system (IGFPS) exhibiting inverse lyotropic liquid crystalline (LLC) phases was developed by simple solution addmixture method. Polarized light microscopy (PLM), small angle X-ray scattering (SAXS), Differential scanning calorimeter (DSC) and oscillatory rheological assessments were performed to ascertain microstructural modulations. The developed system was examined for minimum gelling volume, gelling time, swelling behavior, mucoadhesion, in-vitro antifungal activity and in-vitro drug release. Results: SAXS study identifies coexistence of Im3m cubic phase with HCP P63/mmc u n c o r r e c t e d p r o o f 2 hexagonal structures. SAXS and DSC data highlight DMSO's unique ability to work both as a kosmotropic or chaotropic solvent and to be a function of its concentration.In-vitro antifungal test results point out the concentration of DMSO to be a controlling factor in drug release and diffusion. In-vitro drug release kinetic studies reveal most of the gel samples to follow matrix model and anomalous type release as implied by Peppas model. Conclusion:Finally, the antifungal IGFPS formulated were found to have the required low viscosity, responsive sol-gel phase transition, appreciative mechanical properties and desirable antifungal effect with sustained drug release performance.