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Statins, widely prescribed for cardiovascular diseases, are also being eyed for management of age-related macular degeneration (AMD). Poor bioavailability and blood-aqueous barrier may however limit significant ocular concentration of statins following oral administration. We for the first time propose and investigate local application of atorvastatin (ATS; representative statin) loaded into solid lipid nanoparticles (SLNs), as self-administrable eye drops. Insolubility, instability, and high molecular weight > 500 of ATS, and ensuring that SLNs reach posterior eye were the challenges to be met. ATS-SLNs, developed (2339/DEL/ 2014) using suitable components, quality-by-design (QBD) approach, and scalable hot high-pressure homogenization, were characterized and evaluated comprehensively for ocular suitability. ATS-SLNs were 8 and 12 times more bioavailable (AUC) in aqueous and vitreous humor, respectively, than free ATS. Three-tier (in vitro, ex vivo, and in vivo) ocular safety, higher corneal flux (2.5-fold), and improved stability (13.62 times) including photostability of ATS on incorporation in ATS-SLNs were established. Autoclavability and aqueous nature are the other highlights of ATS-SLNs. Presence of intact fluorescein-labeled SLNs (F-SLNs) in internal eye tissues post-in vivo application as eye drops provides direct evidence of successful delivery. Perinuclear fluorescence in ARPE-19 cells confirms the effective uptake of F-SLNs. Prolonged residence, up to 7 h, was attributed to the mucus-penetrating nature of ATS-SLNs.

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Abstract-Experimental study on a cylindrical Dielectric Resonator Antenna (DRA) using barium titanate (BaTiO 3 ) is presented in this paper. The antenna is fed with a 50 Ω microstrip transmission line at frequency around 2.5 GHz. High dielectric constant (ε r = 1000) resonator samples with different thickness are employed. The return loss, input impedance and radiation patterns are studied. Design simulation results using CST software also presented.

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Aim: Evaluation of solid lipid nanoparticles (SLNs) for ocular delivery of isoniazid (INH). Materials & methods: INH-SLNs were characterized for morphological, thermal, crystalline and nuclear magnetic resonance properties. In vitro release and ex vivo corneal permeability of INH-SLNs was also evaluated. Proof-of-concept uptake studies were performed in corneal and conjunctival cell lines and in vivo in rat eye using fluorescein-labeled SLNs. Antimycobacterial activity of INH-SLNs was confirmed. In vivo aqueous humor pharmacokinetics, toxicity and tolerance was performed in rabbit/rat eye. Results: INH-SLNs showed extended release (48 h), enhanced corneal permeability (1.6-times), five-times lower MIC, significant in vitro and in vivo uptake of fluorescein-labeled SLNs, 4.2-times ocular bioavailability (area under the curve) and in vivo acute and repeat dose safety. Conclusion: INH-SLNs are an effective ocular delivery system.

The study aims to develop high drug-loaded (about 15% lipid matrix) curcumin solid lipid nanoparticles (CSLNs) for wound healing. CSLNs prepared by hot, high-pressure homogenization, without using organic solvents, were optimized using the Taguchi design followed by the central composite design. The optimized CSLNs exhibited a high assay/drug content (0.6% w/w), solubility (6 × 105 times), and EE (75%) with a particle size < 200 nm (PDI—0.143). The CSLNs were safe (in vitro and in vivo), photostable, autoclavable, stable up to one year at 30 °C and under refrigeration and exhibited a controlled release (zero-order; 5 days). XRD, FTIR, and DSC confirmed solubilization and entrapment of the curcumin within the SLNs. TEM and FESEM revealed a smooth and spherical shape. The CSLNs showed a significant antimicrobial effect (MIC of 64 µg/mL for planktonic cells; 512 µg/mL for biofilm formation; and 2 mg/mL for mature biofilm) against Staphylococcus aureus 9144, while free curcumin dispersion did not exhibit any effect. This is the first report on the disruption of mature biofilms by curcumin solid lipid nanoparticles (CSLNs). The cell proliferation potential of CSLNs was also evaluated in vitro while the wound healing potential of CSLNs (incorporated in a hydrogel) was assessed in vivo. In (i) nitrogen mustard gas and (ii) a full-thickness excision wound model, CSLNs exhibited (a) significantly faster wound closure, (b) histologically and immunohistochemically better healing, (c) lower oxidative stress (LPO) and (d) inflammation (TNFα), and (e) increased angiogenesis (VEGF) and antioxidant enzymes, i.e., catalase and GSH levels. CSLNs thus offer a promising modern wound therapy especially for infected wounds, considering their effects in mature biofilm disruption.

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