Design of Topical Moxifloxacin Mucoadhesive Nanoemulsion for the Management of Ocular Bacterial Infections

Evaluation of Pregabalin bioadhesive multilayered microemulsion IOP-lowering eye drops

In spite of available treatment options, glaucoma continues to be a leading cause of irreversible blindness in the world. Current glaucoma medications have multiple limitations including: lack of sustained action; requirement for multiple dosing per day, ocular irritation and limited options for drugs with different mechanisms of action. Previously, we demonstrated that pregabalin, a drug with high affinity and selectivity for CACNA2D1, lowered IOP in a dose-dependent manner. The current study was designed to evaluate pregabalin microemulsion eye drops and to estimate its efficacy in humans using in silico methods. Molecular docking studies of pregabalin against CACNA2D1 of mouse, rabbit, and human were performed. Pregabalin microemulsion eye drops were characterized using multiple in vivo studies and its stability was evaluated over one year at different storage conditions. Molecular docking analyses and QSPR of pregabalin confirmed its suitability as a new IOP-lowering medication that functions using a new mechanism of action by binding to CACNA2D1 in all species evaluated. Because of its prolonged corneal residence time and corneal penetration enhancement, a single topical application of pregabalin ME can provide an extended IOP reduction of more than day in different animal models. Repeated daily dosing for 2 months confirms the lack of any tachyphylactic effect, which is a common drawback among marketed IOP-lowering medications. In addition, pregabalin microemulsion demonstrated good physical stability for one year, and chemical stability for 3-6 months if stored below 25 °C. Collectively, these outcomes greatly support the use of pregabalin eye drops as once daily IOP-lowering therapy for glaucoma management.

Formulation and In Vitro-Ex vivo Evaluation of Cannabidiol and Cannabidiol-Valine-Hemisuccinate Loaded Lipid-Based Nanoformulations for Ocular Applications

The goal of this investigation is to develop stable ophthalmic nanoformulations containing cannabidiol (CBD) and its analog cannabidiol-valine-hemisuccinate (CBD-VHS) for improved ocular delivery. Two nanoformulations, nanoemulsion (NE) and nanomicelles (NMC), were developed and evaluated for physicochemical characteristics, drug-excipient compatibility, sterilization, thermal analysis, surface morphology, ex-vivo transcorneal permeation, corneal deposition, and stability. The saturation solubility studies revealed that among the surfactants tested, Cremophor EL had the highest solubilizing capacity for CBD (23.3 ± 0.1 mg/mL) and CBD-VHS (11.2 ± 0.2 mg/mL). The globule size for the lead CBD formulations (NE and NMC) ranged between 205 and 270 nm while CBD-VHS-NMC formulation had a particle size of about 78 nm. The sterilized formulations, except for CBD-VHS-NMC at 40 °C, were stable for three months of storage (last time point tested). Release, in terms of CBD, in the in-vitro release/diffusion studies over 18 h, were faster from the CBD-VHS nanomicelles (38 %) compared to that from the CBD nanoemulsion (16 %) and nanomicelles (33 %). Transcorneal permeation studies revealed improvement in CBD permeability and flux with both formulations; however, a greater improvement was observed with the NMC formulation compared to the NE formulation. In conclusion, the nanoformulations prepared could serve as efficient topical ocular drug delivery platforms for CBD and its analog.

Precise Fabrication of Ocular Inserts Using an Innovative Laser-Driven CaliCut Technology: In Vitro and in Vivo Evaluation

Ocular inserts offer distinct advantages, including a preservative-free drug delivery system, the ability to provide tailored drug release, and ease of administration. The present research paper delves into the development of an innovative ocular insert using CaliCut technology. Complementing the hot melt extrusion (HME) process, CaliCut, an advanced technology in ocular insert development, employs precision laser gauging to achieve impeccable cutting of inserts with desired dimensions. Its intelligent control over the stretching process through auto feedback-based belt speed adjustment ensures unparalleled accuracy and consistency in dosage form manufacturing. Dry eye disease (DED) poses a significant challenge to ocular health, necessitating innovative approaches to alleviate its symptoms. In this pursuit, castor oil has emerged as a promising therapeutic agent, offering beneficial effects by increasing the thickness of the lipid layer in the tear film, thus improving tear film stability, and reducing tear evaporation. To harness these advantages, this study focuses on the development and comprehensive characterization of castor oil-based ocular inserts. Additionally, in-vivo irritancy evaluation in rabbits has been undertaken to assess the inserts' safety and biocompatibility. By harnessing the HME and CaliCut techniques in the formulation process, the study demonstrates their instrumental role in facilitating the successful development of ocular inserts.

Nanoemulsions: summary of a decade of research and recent advances

Nanoemulsions consist of a combination of several components such as oil, water, emulsifiers, surfactants and cosurfactants. Various techniques for producing nanoemulsions include high-energy and low-energy approaches such as high-pressure homogenization, microfluidization, jet disperser and phase inversion methods. The properties of a formulation can be influenced by elements such as the composition, concentration, size and charge of droplets, which in turn can affect the technique of manufacture. Characterization is conducted by the assessment of several factors such as physical properties, pH analysis, viscosity measurement and refractive index determination. This article offers a thorough examination of the latest developments in nanoemulsion technology, with a focus on their wide-ranging applications and promising future possibilities. It also discusses the administration of nanoemulsions through several methods.

Gatifloxacin Loaded Nano Lipid Carriers for the Management of Bacterial Conjunctivitis

Bacterial conjunctivitis (BC) entails inflammation of the ocular mucous membrane. Early effective treatment of BC can prevent the spread of the infection to the intraocular tissues, which could lead to bacterial endophthalmitis or serious visual disability. In 2003, gatifloxacin (GTX) eyedrops were introduced as a new broad-spectrum fluoroquinolone to treat BC. Subsequently, GTX use was extended to other ocular bacterial infections. However, due to precorneal loss and poor ocular bioavailability, frequent administration of the commercial eyedrops is necessary, leading to poor patient compliance. Thus, the goal of the current investigation was to formulate GTX in a lipid-based drug delivery system to overcome the challenges with the existing marketed eyedrops and, thus, improve the management of bacterial conjunctivitis. GTX-NLCs and SLNs were formulated with a hot homogenization-probe sonication method. The lead GTX-NLC formulation was characterized and assessed for in vitro drug release, antimicrobial efficacy (against methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa), and ex vivo permeation. The lead formulation exhibited desired physicochemical characteristics, an extended release of GTX over a 12 h period, and was stable over three months at the three storage conditions (refrigerated, room temperature, and accelerated). The transcorneal flux and permeability of GTX from the GTX-NLC formulation were 5.5- and 6.0-fold higher in comparison to the commercial eyedrops and exhibited a similar in vitro antibacterial activity. Therefore, GTX-NLCs could serve as an alternative drug delivery platform to improve treatment outcomes in BC.

Development and In vivo Pharmacokinetic and Pharmacodynamic Evaluation of an Oral Innovative Cyclodextrin Complexed Lipid Nanoparticles of Irbesartan Formulation for Enhanced Bioavailability

Background: Irbesartan (IR) is used in the treatment of hypertension, heart failure, and nephropathy in Type II diabetes. IR bioavailability is limited by poor solubility and presystemic metabolism. In our previous investigations, cyclodextrin (HPβCD) complexed solid lipid nanoparticles (SLNs) of IR were prepared, optimized, and characterized. The current study aimed to confirm the reproducibility of the previous methodology and to evaluate the pharmacokinetic (PK) and pharmacodynamic (PD) performance of the selected lead formulations in an experimental animal model. Methods: SLNs were prepared by hot homogenization followed by probe sonication with IR/HPβCD inclusion complex loaded into a solid lipid (Dynasan 112). SLNs were evaluated for physical characteristics, drug content, entrapment efficiency, in vitro release profile, and surface morphology. The pharmacokinetic and pharmacodynamic behavior of the SLNs were evaluated in Wistar rats. Results: Photon correlation spectroscopy, drug content, entrapment efficiency, and dissolution studies results were reproducible and consistent with our earlier investigation. PK studies showed 2.1-, 6.6-, and 9.9-fold improvement in the relative oral bioavailability of the drug from IR-HPβCD, IR-SLN, and IR-HPβCD-SLN formulations, respectively compared to IR suspension. However, IR-HPβCD-SLNs showed 1.5- and 4.7-fold improvement in the relative oral bioavailability of the drug compared to IR-SLN and IR-HPβCD formulations, respectively. PD studies in hypertensive Wistar rats showed a good control over systolic blood pressure for 48 h for SLN formulations compared to 2 h for IR suspension. However, the IR-HPβCD inclusion complex exhibited immediate antihypertensive activity (0.5 h) with a period of systolic blood pressure control similar to IR suspension. Conclusions: The current approach exhibited improved oral bioavailability along with improved and prolonged pharmacodynamic effect.

Cannabidiol Loaded Topical Ophthalmic Nanoemulsion Lowers Intraocular Pressure in Normotensive Dutch-Belted Rabbits

Cannabidiol (CBD) is the major non-psychoactive and most widely studied of the cannabinoid constituents and has great therapeutic potential in a variety of diseases. However, contradictory reports in the literature with respect to CBD's effect on intraocular pressure (IOP) have raised concerns and halted research exploring its use in ocular therapeutics. Therefore, the current investigation aimed to further evaluate CBD's impact on the IOP in the rabbit model. CBD nanoemulsions, containing Carbopol^® 940 NF as a mucoadhesive agent (CBD-NEC), were prepared using hot-homogenization followed by probe sonication. The stability of the formulations post-moist-heat sterilization, in terms of physical and chemical characteristics, was studied for three different storage conditions. The effect of the formulation on the intraocular pressure (IOP) profile in normotensive Dutch Belted male rabbits was then examined. The lead CBD-NEC formulation (1% w/v CBD) exhibited a globule size of 259 ± 2.0 nm, 0.27 ± 0.01 PDI, and 23.2 ± 0.4 cP viscosity, and was physically and chemically stable for one month (last time point tested) at 4 °C, 25 °C, and 40 °C. CBD-NEC significantly lowered the IOP in the treated eyes for up to 360 min, with a peak drop in IOP of 4.5 mmHg observed at the 150 min time point, post-topical application. The IOP of the contralateral eye (untreated) was also observed to be lowered significantly, but the effect lasted up to the 180 min time point only. Overall, topically administered CBD, formulated in a mucoadhesive nanoemulsion formulation, reduced the IOP in the animal model studied. The results support further exploration of CBD as a therapeutic option for various inflammation-based ocular diseases.