Sodium hyaluronate 0.30% ocular gel versus sodium hyaluronate 0.18% eye drop in the treatment of moderate to severe dry eye disease.

PURPOSE: Compare 0.30% sodium hyaluronate (0.30%HA) ocular gel with 0.18%HA eye drops in terms of improvement of ocular signs and symptoms, in patients with moderate to severe dry eye disease (DED). METHODS: This was a multicentric, randomized, investigator-masked, non-inferiority, comparative study conducted over 84 days. Three visits were scheduled, testing fluorescein corneal and conjunctival staining (Oxford and Van Bijsterveld scores), tear film break-up time (TBUT), Schirmer test, DED symptoms, 5-Item-Dry-Eye-Questionnaire (5-DEQ), patient and investigator satisfaction and frequency of instillation. RESULTS: At Day 35 (D35) and Day 84 (D84), both groups (n = 35 each) had a significant improvement in corneal staining (p < 0.001) with no inter-group difference. Van Bijsterveld score improved earlier (D35) for 0.30%HA suggesting a faster effect on conjunctival epithelium healing. There was no difference between the two concentrations in terms of TBUT or Schirmer improvements; however, the Schirmer test increase was only significant for 0.30%HA at D35 (p = 0.040). At D35 and D84, both groups showed similar improvements of DED symptoms and DEQ-5 score. Furthermore, treatment satisfaction was similar for the 2 formulations suggesting that daily use of 0.30%HA do not cause gel-related blurred vision disturbances. Frequency of instillation was similar for both groups. CONCLUSION: Our study demonstrates the non-inferiority of 0.30%HA gel compared to 0.18%HA solution in patients with moderate to severe DED. Because of its gel formulation and higher HA concentration providing prolonged comfort without causing visual disturbances, 0.30%HA gel might be adapted for bedtime use or during the day in more severe conditions.

Thermosensitive and mucoadhesive in situ ocular gel for effective local delivery and antifungal activity of itraconazole nanocrystal in the treatment of fungal keratitis.

Itraconazole is a lipophilic drug, which limits its absorption for ocular administration. This study focused on the incorporation of itraconazole into nanocrystalline carrier system with stabilizer Pluronic® F127 and was further formulated into thermosensitive in situ ocular gel. Itraconazole nanocrystals (ITZ-NCs) were fabricated using media milling method with ultra-small-scale device. The obtained nanocrystals were observed to have a better in vitro activity against C. albicans (CA) compared to free itraconazole suspension in water. Furthermore, the optimization of the thermosensitive ocular gel formula was carried out with a central composite design, using three types of polymers, namely Pluronic® F127, Pluronic® F68, and hydroxypropyl methylcellulose (HPMC). After being dispersed into the optimized thermosensitive gel base, ITZ-NCs did not alter in terms of physical characteristics. Ex vivo ocularkinetic studies on infected porcine eye models showed a better profile of the optimized formula of thermosensitive in situ ocular gel when compared to standard gel base. Importantly, the ex vivo antifungal activity of these preparations was also increased, with a 93% decrease in the CA population observed after 48 h in infected porcine eye model. Altogether, this work has provided evidence of a novel approach in developing more advanced treatments for fungal keratitis.

Preparation and characterization of bear bile-loaded pH sensitive in-situ gel eye drops for ocular drug delivery.

OBJECTIVES: In this study, a stable bear bile-loaded pH sensitive in-situ eye drop gel was prepared for sustain delivery and enhanced therapeutic application. MATERIALS AND METHODS: Bear bile-loaded in-situ ocular gels with different Carbopol/Hydroxypropyl methylcellulose (HPMC) ratios were prepared and their stability was tested in PBS at a series of pH at 40 °C. The morphology was observed by SEM examination and rheology was observed by Rheometer equipped with a 60-mm cone-plate at apex angle of 1°. Gel erosion and release kinetics of Tauroursodeoxycholic acid (TUDCA) was determined by HPLC. While, the in vivo dwelling time was obtained after administering the fluorescent-loaded gel in ocular disease-free New Zealand rabbits. Finally, biocompatibility and toxicity was observed by irritation test and H&E staining of eye-ball tissues, respectively. RESULTS: The bear bile-loaded in-situ ocular gel showed excellent stability at different pH (pH 5.0, 5.5, 6.0, 6.5, 7.0 and 8.0) up to 5 days, and bear bile extract significantly attenuated the gelling ability of the in-situ gel. The viscosity of in-situ gels formulation was decreased with increase in shear rate (0.01 to 100 s-1), and morphological examination of freeze-dried preparation showed three-dimensional reticular structure at physiological pH. The in-situ ocular gel exhibited promising sustained drug release up to 160 min in vitro, and showed prolonged retention time up to 3-folds in vivo. Finally, the biocompability data confirmed that the formulation did not induce any toxic effects and was completely compatible with eye tissues. CONCLUSION: pH sensitive in-situ ocular gel provides new research opportunities to efficiently treat eye diseases.

Formulation and evaluation of new long acting metoprolol tartrate ophthalmic gels.

The rationale of the present work is to formulate and evaluate metoprolol tartrate (MT), which is a beta-1 selective adrenergic blocking agent in a new ocular gel delivery system; this is our way and method to increase its contact to the cornea, giving a longer time of drug contact to the eye and slow possible release from the preparation. Metoprolol tartrate is chosen as a candidate for gel formulation because although it has been available for a few years as ophthalmic solutions, it has not been marketed as an ocular gel yet. Two polymers; Carbopol 934 and Pluronic F127 (PF127) were used in two different concentrations in this study. Metoprolol tartrate was used in two concentrations, 0.5% and 1% (w/w). All formulations were exposed to visual examinations, pH measurement, in vitro release, rheological study and differential scanning calorimetry (DSC). Results showed that all formulations were clear, showed pH within the acceptable range suitable to be administered in the eye, and exhibited pseudoplastic flow behavior. DSC results concluded that, MT was compatible with different polymers used. In vitro release results showed that the release rate of metoprolol tartrate from gel preparations decreased as an inverse function of polymer concentration, and the release rate of the drug increased as the initial concentration increased. Intra-ocular pressure (IOP) measurements of rabbit's eye treated with 1% (w/w) metoprolol tartrate in gel formulations with different concentrations of the polymer were determined. Carbopol 934 gel formulations showed that this polymer extended the duration of pressure reducing effect of MT to more than 5hr when compared with Pluronic F127 gel formulations. The area above the curve (AAC), maximum response, time of maximum response (t max), and the duration of the drug action were also calculated.

Ion-activated In Situ Gelling Ophthalmic Delivery Systems of Azithromycin.

Gelation of pectin caused by divalent cations especially calcium ions has been applied to develop an ophthalmic formulation of azithromycin in the present study. Rapid elimination of drug on instillation into cul de sac would be minimal with in situ gelling ophthalmic solution leading to increased precorneal contact time and prolonged drug delivery. In the formulation development studies pectin was used in different concentrations (1-5% w/v) and different proportions of the hydrocolloids hydroxypropyl methylcellulose and sodium carboxymethyl cellulose of different grades of viscosity were used. The primary criteria for formulation optimization were gelling capacity and rheological behaviour. In addition, formulations were evaluated for pH, and antimicrobial efficacy and drug release. The clarity, pH, gelation in simulated tear fluid and rheological properties of the optimized formulations were satisfactory. The formulations inhibited the growth of Staphylococcus aureus effectively in cup-plate method and were proved to be safe and non irritant on rabbit eyes. The results indicate that pectin based in situ gels can be successfully used to prolong the duration of action of azithromycin.