Enhancement of lomefloxacin Hcl ocular efficacy via niosomal encapsulation: in vitro characterization and in vivo evaluation

Abstract

The aim of this study is to develop and evaluate niosomal dispersions loaded with the hydrophilic drug; lomefloxacin Hcl (LXN) for the management of ocular bacterial conjunctivitis. LXN-loaded niosomes were prepared by the thin film hydration method following a full factorial formulation design. Two independent variables were evaluated: the type of surfactant (X1) and the surfactant:cholesterol ratio (X2). The dependent variables comprised entrapment efficiency (EE%: Y1), particle size (PS: Y2) and zeta potential (ZP: Y3). The optimum formulation, N-LXN14 (Tw60: CH, 1:1), was spherical in shape and exhibited EE% of 68.41 ± 0.07, PS of 176.0 ± 0.98 and ZP of -40.70 ± 2.20 with a sustained release profile over 8 hours following the Higuchi model. N-LXN14 proved good physicochemical stability under refrigeration up to 3 months. Ocular irritancy test showed no signs of ocular toxicity, confirming the safety and suitability for ocular application. Microbiological evaluation of the antibacterial effect of N-LXN14 was conducted using the susceptibility test and through the induction of topical conjunctivitis by Staphylococcus aureus (S. aureus) followed by topical therapy. Susceptibility test manifested significantly higher percent inhibition of S. aureus and higher AUC of N-LXN14 (604.59 ± 0.05) compared to the commercial product (126.25 ± 0.049). Both clinical observation and colony count of the infected eyes after eight days of treatment demonstrated significant improvement in therapeutic response. The infected eyes were completely healed with eradication of S. aureus. In conclusion, the results showed that LXN niosomal dispersions may serve as a promising superior ocular delivery system in the treatment of bacterial conjunctivitis.

<p>Use of transethosomes for enhancing the transdermal delivery of olmesartan medoxomil: in vitro, ex vivo, and in vivo evaluation</p>

“…Particle aggregation is less likely to occur for charged vesicles having a ZP of $|30|mV because of electrostatic repulsion. 46 The ANOVA results showed that both independent variables, SAA type (X 1 ) and PC:SAA ratio (X 2 ), showed a significant effect on ZP (P,0.0001) as depicted in Table 2 and graphically illustrated as response 3-D plots in Figure 1D. The ZP of vesicles decreased when using Tweens rather than Spans which could be attributed to the higher HLB values of Tweens compared to Spans.…”

Vancomycin-loaded niosomes integrated within pH-sensitive in-situ forming gel for treatment of ocular infections while minimizing drug irritation

“…Furthermore, non‐ionic surfactant vesicles (i.e. niosomes) have been exploited for ocular drug delivery to improve permeability and bioavailability of drugs and to achieve localized drug action since their sizes and low penetrability through epithelium maintain the drug localized at the site of administration and increase precorneal residence time . A further significant increase in the precorneal residence time and bioavailability of drugs can be achieved via utilizing viscous/semisolid delivery systems, such as creams, ointments and gels.…”

“…niosomes) have been exploited for ocular drug delivery to improve permeability and bioavailability of drugs and to achieve localized drug action since their sizes and low penetrability through epithelium maintain the drug localized at the site of administration and increase precorneal residence time. [11][12][13] A further significant increase in the precorneal residence time and bioavailability of drugs can be achieved via utilizing viscous/semisolid delivery systems, such as creams, ointments and gels. In one study, vancomycin was administered as a 1% ophthalmic ointment for treatment of ocular MRSA and methicillin-resistant Staphylococcus epidermidis infections and resulted in high antibacterial efficacy.…”

Sustained ocular delivery of Dorzolamide-HCl via proniosomal gel formulation: in-vitro characterization, statistical optimization, and in-vivo pharmacodynamic evaluation in rabbits

“…( 2017 ) studied the effect of formulation variables on the in-vitro characters of ocular Ketoconazole-loaded proniosomal gels and carried out both ex-vivo and in-vivo studies. Ocular proniosomal gels of Lomefloxacin-HCl were prepared using different types of nonionic surfactants alone and as mixtures with Span 60 in order to improve its ocular bioavailability for the management of bacterial conjunctivitis (Khalil et al., 2017 ). Tacrolimus-loaded proniosomal gel containing poloxamer 188 and lecithin as surfactants, Cholesterol as a stabilizer and minimal amount of ethanol were prepared and characterized (Li et al., 2014 ).…”