Design and optimization of acetazolamide nanoparticle-laden contact lens using statistical experimental design for controlled ocular drug delivery.

This study aims to formulate and evaluate Eudragit nanoparticles-laden hydrogel contact lenses for controlled delivery of acetazolamide (ACZ) using experimental design. Eudragit S-100 was selected for the preparation of nanoparticles. The optimization of Eudragit S100 concentration (X1), polyvinyl alcohol concentration (X2), and the sonication time (X3) was attempted by applying a central composite experimental design.

An update on the latest strategies in retinal drug delivery.

Introduction: Retinal drug delivery has witnessed significant advancements in recent years, mainly driven by the prevalence of retinal diseases and the need for more efficient and patient-friendly treatment strategies.

Areas Covered: Advancements in nanotechnology have introduced novel drug delivery platforms to improve bioavailability and provide controlled/targeted delivery to specific retinal layers. This review highlights various treatment options for retinal diseases.

An Update on Strategies to Deliver Protein and Peptide Drugs to the Eye.

In the past few decades, advancements in protein engineering, biotechnology, and structural biochemistry have resulted in the discovery of various techniques that enhanced the production yield of proteins, targetability, circulating half-life, product purity, and functionality of proteins and peptides. As a result, the utilization of proteins and peptides has increased in the treatment of many conditions, including ocular diseases. Ocular delivery of large molecules poses several challenges due to their high molecular weight, hydrophilicity, unstable nature, and poor permeation through cellular and enzymatic barriers.

Effect of resin extract in 3-nitropropionic acid-induced Huntington's disease symptoms in Sprague-Dawley rats.

Background And Purpose: Huntington's disease (HD) is a neurodegenerative disease characterized by neuronal death in the striatum. Asiatic acid is an active component of (Dipterocarpaceae) plants with neuroprotective activity and is considered an acceptable therapeutic candidate for different neurodegenerative diseases. In the present study, the beneficial pharmacological action of resin extract (SRRE) was assessed in 3-nitropropionic acid (3-NP)-induced HD in rats.

A review of recent advances in the novel therapeutic targets and immunotherapy for lung cancer.

Lung cancer is amongst the most pervasive malignancies having high mortality rates. It is broadly grouped into non-small-cell lung cancer (NSCLC) and small-cell lung cancer (SCLC). The concept of personalized medicine has overshadowed the conventional chemotherapy given to all patients with lung cancer.

Nanocarriers for the Delivery of Neuroprotective Agents in the Treatment of Ocular Neurodegenerative Diseases.

Retinal neurodegeneration is considered an early event in the pathogenesis of several ocular diseases, such as diabetic retinopathy, age-related macular degeneration, and glaucoma. At present, there is no definitive treatment to prevent the progression or reversal of vision loss caused by photoreceptor degeneration and the death of retinal ganglion cells. Neuroprotective approaches are being developed to increase the life expectancy of neurons by maintaining their shape/function and thus prevent the loss of vision and blindness.

Protective effect of probiotics and ascorbic acid on bile duct ligation-induced chronic hepatic encephalopathy in rats.

Background And Purpose: Hepatic encephalopathy (HE) is a brain dysfunction caused by acute and chronic hepatic failure. The pathogenesis of HE is unknown, although small intestinal bacterial overgrowth associated with chronic liver damage, hyperammonemia, and oxidative stress are considered major factors for HE. Effective lowering of circulating ammonia and neuroinflammation is the main strategy for preventing and treating HE in cirrhosis.

Polyamide/Poly(Amino Acid) Polymers for Drug Delivery.

Polymers have always played a critical role in the development of novel drug delivery systems by providing the sustained, controlled and targeted release of both hydrophobic and hydrophilic drugs. Among the different polymers, polyamides or poly(amino acid)s exhibit distinct features such as good biocompatibility, slow degradability and flexible physicochemical modification. The degradation rates of poly(amino acid)s are influenced by the hydrophilicity of the amino acids that make up the polymer.

Tailored Doxycycline Hyclate Loaded In Situ Gel for the Treatment of Periodontitis: Optimization, In Vitro Characterization, and Antimicrobial Studies.

Currently, periodontitis is treated by oral dosage forms (antibiotics) which shows systemic side effects and failed to reach the therapeutic concentration (above minimum inhibitory concentration, MIC) in the periodontal pocket. The present study aimed to overcome the above issues, by designing tailored doxycycline hyclate laden in situ gel by Poloxamer 407, chitosan, and polyethylene glycol 600. The in situ gel-forming system has attracted attention owing to its ability of sustained drug release above MIC, easy administration (syringeability), and high drug retention (localization) in the periodontal cavity.

Oral bioavailability improvement of felodipine using tailored microemulsion: Surface science, ex vivo and in vivo studies.

Felodipine is a calcium channel blocker, which shows low oral bioavailability (<15%) owing to poor water solubility and high first pass metabolism. The aim of the present investigation was to study the surface science (dynamic surface tension) and characteristics of microemulsion (Capmul MCM, Tween 20 and polyethylene glycol) to enhance the oral bioavailability of felodipine by improving permeability of the drug in the intestine. The paper is the first attempt to study the stability of oil-water interface of microemulsion using bubble tensiometer.

Novel Poly(vinylpyrrolidone)-Coated Silicone Contact Lenses to Improve Tear Volume During Lens Wear: In Vitro and In Vivo Studies.

Poly(vinylpyrrolidone) (PVP-K90) is widely used to manage dry eye syndrome (DES). The marketed eye drop solutions (high dose) need frequent instillation, affecting the routine lifestyle of patients. PVP-K90-laden contact lenses can be used to overcome the limitations of eye drop solutions (low bioavailability and frequent instillation).

Multiple drug delivery from the drug-implants-laden silicone contact lens: Addressing the issue of burst drug release.

A fixed combination of bimatoprost/timolol eye drop solution is used to manage the elevated intra-ocular pressure in glaucoma patients, including individuals whose condition is poorly controlled by monotherapy. Eye drop solutions are generally given in high dose, due to poor ocular bioavailability. The high ocular dose of bimatoprost and timolol lead to hyperaemia and systemic cardiac side effects respectively.

Tailored gatifloxacin Pluronic® F-68-loaded contact lens: Addressing the issue of transmittance and swelling.

Loading of gatifloxacin in contact lenses affects critical lens properties (optical and swelling) owing to drug precipitation in the contact lens matrix. The presence of Pluronic® F-68 in the packaging solution creates in-situ micelles in the contact lens to dissolve gatifloxacin precipitates and provide sustained drug release. The micelles further improved the drug uptake from the drug-packaging solution to create an equilibrium of drug between the lens matrix and the packaging solution.

Lidocaine tripotassium phosphate complex laden microemulsion for prolonged local anaesthesia: In vitro and in vivo studies.

Lidocaine is widely used as a local anaesthetic in the clinical practice to manage pre- and post-operative pain, skin burns, etc. However, the short duration of action (< 2 h) of marketed dosage forms limit their ability to meet clinical needs. Herein, we prepared a lidocaine-tPP(tri potassium phosphate)-complex loaded microemulsion to achieve greater penetration, followed by destabilization of microemulsion in the skin layer to precipitate oil-complex to produce a depot effect in the skin for prolonging the effects of anaesthesia.

Plackett-Burman design for screening of critical variables and their effects on the optical transparency and swelling of gatifloxacin-Pluronic-loaded contact lens.

The optical and swelling properties of gatifloxacin-loaded contact lens decrease owing to the precipitation of gatifloxacin (on hydration) in the matrix structure of the contact lens. This paper focuses on the use of Pluronic F68 both inside and outside (in the packaging solution) the contact lens to form micelles to dissolve the gatifloxacin precipitates and not limited to sustain the release of gatifloxacin. The aim of this study was to screen the critical variables affecting the optical and swelling properties of gatifloxacin-loaded contact lens.

Effect of gold nanoparticles on timolol uptake and its release kinetics from contact lenses: In vitro and in vivo evaluation.

Contact lenses are ideally suited for extended drug delivery to the ocular tissues, but incorporation of any particulate system affects the critical properties of the contact lens. Timolol loading by the conventional soaking method does not significantly alter the critical properties of the contact lens. However, there are challenges of low drug loading and high burst release.

Optimization of a novel in situ gel for sustained ocular drug delivery using Box-Behnken design: In vitro, ex vivo, in vivo and human studies.

The aim of the present research work was to formulate, optimize and evaluate the in-situ gel for the ophthalmic drug delivery using the combination of gellan gum and carbopol 934P. The Box-Behnken design was applied to optimize the concentration of gellan gum (X), carbopol 934P (X) and benzododecenium bromide (X) to achieve the maximum viscosity [at physiological condition; 35 °C, pH 7.4, and simulated tear fluid (STF)], mucoadhesive strength, permeability coefficient and sustained release of the drug from the gel with constraint on the viscosity under the non-physiological condition (25 °C, pH 5).

Contact lenses with dual drug delivery for the treatment of bacterial conjunctivitis.

Currently, bacterial conjunctivitis is treated by frequent administration of antibiotic eye drop solutions, which is tedious and patient noncompliant. Contact lenses could be ideal medical devices to sustain the release of ophthalmic drugs, but the incorporation of the latter can alter the optical and physical properties of the lenses. In addition, many contact lens users have reported the pink eye syndrome, making them unsuitable as ocular medical devices.

Co-delivery of timolol and hyaluronic acid from semi-circular ring-implanted contact lenses for the treatment of glaucoma: in vitro and in vivo evaluation.

Glaucoma is a chronic disease, which is currently treated using frequent high dose applications of an eye drop solution; this method is tedious, and most of patients are non-compliant to it. Contact lenses are emerging as a convenient option to sustain the release of ophthalmic drugs. However, the incorporation of a drug/formulation changes the optical and physical properties of contact lenses.

pH triggered controlled drug delivery from contact lenses: Addressing the challenges of drug leaching during sterilization and storage.

In the present work a novel cyclosporine-loaded Eudragit S100 (pH-sensitive) nanoparticles-laden contact lenses were designed to provide sustained release of cyclosporine at therapeutic rates, without leaching of drug during sterilization and storage period (shelf life). The nanoparticles were prepared by Quasi-emulsion solvent diffusion technique using different weight ratios of cyclosporine to Eudragit S100. The contact lenses with direct drug entrapment were also fabricated (DL-50) for comparison.

Effect of surfactant chain length on drug release kinetics from microemulsion-laden contact lenses.

The effect of surfactant chain lengths [sodium caprylate (C), Tween 20 (C), Tween 80 (C)] and the molecular weight of block copolymers [Pluronic F68 and Pluronic F 127] were studied to determine the stability of the microemulsion and its effect on release kinetics from cyclosporine-loaded microemulsion-laden hydrogel contact lenses in this work. Globule size and dilution tests (transmittance) suggested that the stability of the microemulsion increases with increase in the carbon chain lengths of surfactants and the molecular weight of pluronics. The optical transmittance of direct drug-laden contact lenses [DL-100] was low due to the precipitation of hydrophobic drugs in the lenses, while in microemulsion-laden lenses, the transmittance was improved when stability of the microemulsion was achieved.

Design and optimization of a novel implantation technology in contact lenses for the treatment of dry eye syndrome: In vitro and in vivo evaluation.

Unlabelled: Contact lenses are widely used for ophthalmic drug delivery, but incorporation of drug or formulation in the contact lenses affects its optical and physical property. In the present study, we have designed a novel hyaluronic acid (HA)-laden ring implant contact lenses (modified cast moulding method), to circumvent the changes in critical lens property. The objective was to improve the ocular residence time of HA, by providing sustained ocular HA delivery through implant contact lenses for the treatment of dry eye syndrome.

Extended release of ketotifen from silica shell nanoparticle-laden hydrogel contact lenses: in vitro and in vivo evaluation.

Ketotifen an anti-allergic drug delivered via eye drops has major limitations, including poor ocular bioavailability and poor patient compliance. The objective of the research work was to fabricate ketotifen loaded microemulsion laden hydrogels and silica shell nanoparticle-laden (prepared from microemulsion using octyltrimethoxysilane) hydrogels to achieve extended ocular drug delivery. The porous silica shell membrane was synthesized at the liquid interface of microemulsion, which facilitates the prolongation of drug release duration from hydrogels.

In vitro and in vivo evaluation of novel implantation technology in hydrogel contact lenses for controlled drug delivery.

Glaucoma is commonly treated using eye drops, which is highly inefficient due to rapid clearance (low residence time) from ocular surface. Contact lenses are ideally suited for controlled drug delivery to cornea, but incorporation of any drug loaded particulate system (formulation) affect the optical and physical property of contact lenses. The objective of the present work was to implant timolol maleate (TM) loaded ethyl cellulose nanoparticle-laden ring in hydrogel contact lenses that could provide controlled drug delivery at therapeutic rates without compromising critical lens properties.