Nanoemulsions as a Promising Carrier for Topical Delivery of Etodolac: Formulation Development and Characterization.

This research primarily focuses on the development of innovative topical nanoemulsions for etodolac, aimed at surmounting its inherent limitations. The preparation of etodolac nanoemulsions is accomplished through a combination of high shear homogenization and ultrasonication methods. The optimization of the formulation components is systematically conducted using the design of experiments methodology. The droplet size (DS), polydispersity index (PDI), and zeta potential (ZP) of the optimized formulation were assessed using the differential light scattering (DLS) technique. Surface morphology examinations were conducted using electron microscopy, while interactions between excipients and the drug were analyzed through FTIR analysis. Additionally, in vitro release and ex vivo permeability studies were carried out. Furthermore, anti-inflammatory activity was evaluated in the context of a carrageenan-induced paw edema model in rats. The DS, PDI, and ZP of the optimal formulation were 163.5 nm, 0.141, and -33.1 mV, respectively. The in vitro release profile was assessed as a sustained release by following a non-Fickian drug transport. The flux of etodolac nanoemulsions and coarse dispersions were 165.7 ± 11.7 µg/cm2 h and 59.7 ± 15.2 µg/cm2 h, respectively. Enhanced edema inhibition was observed at 13.4%, 36.5%, and 50.65% for the 6th, 8th, and 24th hours, respectively. Taken together, these results confirmed that nanoemulsions are promising carriers for the topical delivery of etodolac.

Determination of the Toxicity Preferences of Ocular Drug Delivery System by Comparing Two Different Toxicity Bioassays.

Ocular drug delivery methods are highly favored for boosting bioavailability, patient compliance, and lower adverse effects and dose frequency. In addition to preventing adverse effects from the active ingredient, the parts of drug delivery systems must be nontoxic and nonallergic as well. Mitochondrial toxicity test (MTT) and Hen's egg chorioallantois membrane (HET-CAM) assay are the most often utilized tests based on this dilemma. The toxicity of loteprednol etabonate loaded solid lipid nanoparticles, lipid nanostructured carriers, and nanoemulsion were compared. Oleic acid, Precirol®ATO5, and Pluronic® F68 were used in the preparation. Their toxicities were evaluated by using two different toxicity tests (MTT and HET-CAM). The results suggest that there are no significant differences between the HET-CAM and MTT assays. It is noteworthy that the HET-CAM assay offers a more cost-effective and environmentally friendly alternative to the MTT assay, as it does not require cell culture and generates less toxic waste. This information may be useful to consider when selecting between the two assays.

Preparation and Characterization Studies of Dorzolamide-Loaded Ophthalmic Implants for Treating Glaucoma.

Objectives: This study constructed dorzolamide (DRZ)-loaded ophthalmic implants for extended drug delivery and increased drug retention. Materials and Methods: Carboxymethyl cellulose (CMC) and chitosan (CHI) were used to describe the ophthalmic implants. The implants were prepared by the solvent casting technique in presence of polyethylene glycol 6000 (PEG 6000) as plasticizer. Physicochemical characterization studies including mechanical characteristics [tensile strength (TS), elongation at break, and Young's modulus], bioadhesion studies, and in vitro and ex vivo drug release studies were conducted. Results: TS of drug-loaded ophthalmic implants was 10.70 and 11.68 MPa, respectively. Elongation at break of CMC and CHI implants was 62.00% and 59.05%, respectively. The in vitro release profiles fit into Higuchi type kinetic model. Ex vivo release study results for both implants were correlated with in vitro release investigations. Conclusion: CMC and CHI-based implants provide extended drug delivery. Implants prepared using CMC provided a significantly slower in vitro release rate, and drug retention on ocular surfaces increased. Thus, it has been concluded that DRZ-loaded CMC implants could provide effective treatment for glaucoma.

Timolol-loaded ethosomes for ophthalmic delivery: Reduction of high intraocular pressure in vivo.

The beta-adrenoceptor blocker timolol maleate (TML) is a commonly used pharmaceutical agent for the management of glaucoma. Conventional eye drops have limitations due to biological or pharmaceutical factors. Therefore, TML-loaded ethosomes have been designed to mitigate these restrictions and give a viable solution for reducing elevated intraocular pressure (IOP). The ethosomes were prepared using the thin film hydration method. Integrating the Box-Behnken experimental strategy, the optimal formulation was identified. The physicochemical characterization studies were performed on the optimal formulation. Then, in vitro release and ex vivo permeation studies were conducted. The irritation assessment was also carried out with Hen's Egg Test-Chorioallantoic Membrane model (HET-CAM), and in vivo evaluation of the IOP lowering effect was also performed on rats. The physicochemical characterization studies demonstrated that the components of the formulation were compatible with each other. The particle size, zeta potential, and encapsulation efficiency (EE%) were found as 88.23 ± 1.25 nm, -28.7 ± 2.03 mV, and 89.73 ± 0.42 %, respectively. The in vitro drug release mechanism was found as Korsmeyer-Peppas kinetics (R2 = 0.9923). The HET-CAM findings verified the formulation's eligibility for biological applications. The IOP measurements revealed no statistical difference (p > 0.05) between the once-a-day application of the optimal formulation and the three-times-a-day application of the conventional eye drop. A similar pharmacological response was observed at lowered application frequencies. Therefore, it was concluded that the novel TML-loaded ethosomes could be a safe and efficient alternative for glaucoma treatment.

Design and characterization of dexamethasone loaded microsponges for the management of ulcerative colitis.

Ulcerative colitis is an inflammatory condition with ulcerations throughout the colon. The existing remedies have some limitations such as drug inactivation, poor absorption, and adverse reactions. The present study aimed to design novel microsponge formulations to enhance remission of the dexamethasone (as a model pharmaceutical ingredient) in the colon. Microsponges were prepared by using the quasi-emulsion technique. The optimal formulation was selected by applying the design of experiments approach which used methylcellulose (MC) (0.75-2%, w/w), polyvinylalcohol (PVA)(0.5-1%, w/w), and tween 80 (TW80) (1.5-2.5%, w/w). The critical quality attributes were selected as particle size and entrapment efficiency. The particle size and encapsulation efficiency were found as 140.38 ± 9.2 µm and 77.96 ± 3.4 %. After the optimization; morphological, thermal, and physicochemical characterization studies were performed. Ultimately, the optimal formulation was investigated by using the acetic acid-induced ulcerative colitis model in rats. The physicochemical characterization studies confirmed that the formulation components were compatible with each other. The in vitro release mechanisms were fitted to First order kinetics at pH 1.2 (R2:0.9563), and Korsmeyer-Peppas kinetics at pH 4.5 (R2: 0.9877), and pH 6.8 (R2: 0.9706). The medicated microsponges exhibited remarkable recovery compared to the control group of the in vivo ulcerative colitis model (p < 0.05). It could be concluded that microsponges were evaluated as a promising alternative drug delivery system for the management of ulcerative colitis.

Combination of St. John's Wort Oil and Neem Oil in Pharmaceuticals: An Effective Treatment Option for Pressure Ulcers in Intensive Care Units.

Background and Objectives: Phytotherapeutically, various herbal remedies, such as St. John's wort oil, have been introduced as wound care options. Recently, Neem oil has been considered a herbal option for the management of superficial wounds. Wound care is a complex process that involves several factors including the patient, caregiver, and medications. Herbal combinations could be an alternative to the chemical counterparts in the wound care area. This report includes an investigation of the possible supportive impacts of the St. John's wort and Neem oil containing ointment (W Cura G Plus ®) in the management of pressure ulcers (PUs) in three intensive care unit (ICU) patients. Materials and Methods: The ointment was administered to individuals once daily for 42 consecutive days. The status of individuals was macroscopically monitored by measuring the PU area and histopathological assessment of the tissue sections taken on the first and last days of wound treatment. Results: The outcomes of the macroscopic and histopathological techniques exhibited that St. John's wort and Neem oil containing ointment provided a remarkable supportive impact on the patients that suffered from PUs in the ICUs. Conclusions: The combination of St. John's wort and Neem oil could be suggested as an efficient active phytoconstituent for the management of PUs. The herbal ointments may be suggested as an alternative for the patients that have PUs in the ICUs.

Loteprednol-Loaded Nanoformulations for Corneal Delivery by Quality-by-Design Concepts: Optimization, Characterization, and Anti-inflammatory Activity.

Loteprednol etabonate (LE) is a topical corticosteroid that uses inflammatory conditions of the eye. It has a low ocular bioavailability and side effects such as corneal disorder, eye discharge, and ocular discomfort. Therefore, it was decided to select the delivery systems, which are solid lipid nanoparticles (SLN), nanostructured lipid carriers (NLC), and nanoemulsion (NE). Design of experiments (DoE) of SLN, NLC, and NE formulations were formulated by using the quality by design (QbD) approach. Precirol® ATO 5 and oleic acid were used as solid and liquid lipids, respectively, in SLN, NLC, and NE formulations. Physiochemical characterization was performed on the formulations. The optimized formulations' inflammatory effects have been appraised on human corneal epithelial cells employing the ELISA test. Physicochemical characterization studies and inflammatory effects were appraised. The sizes of optimized formulations of SLN, NLC, and NE were 86.19 nm, 82.38 nm, and 126.35 nm, respectively, with minimum polydispersity. The release behavior of the formulations is composed of both diffusion and erosion. ELISA test results proved that the formulations significantly reduced IL-1 and IL-6 levels (p < 0.05). D-optimal mixture experimental design allowed us to develop the most precise formulations of SLN, NLC, and NE. Furthermore, the optimized formulations could be promising candidates for treating an inflammation-based corneal disease of the eye.

Development of lipid nanoparticles for transdermal loteprednol etabonate delivery.

AIM: Loteprednol etabonate (LE) is a new generation corticosteroid that is used for the treatment of inflammatory and allergic conditions of the eye. Therefore, solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) were attempted to improve transdermal LE delivery for the first time. METHODS: SLN and NLC were produced by hot homogenisation and ultrasonication technique. Their physical stability was monitored for 3 months of storage. Drug release and permeation of SLN and NLC through the porcine skin were investigated. RESULTS: It was determined that SLN and NLC mean particle size of 139.1 nm had a homogeneous particle size distribution (∼0.169 PI) and the mean charge was -23.6. They were found to be stable both physically and chemically at room temperature. CONCLUSION: SLN and NLC formulations of LE can be stated among the systems that can be an alternative to conventional systems with fewer side-effects in the treatment of inflammatory problems.

Influence of Vehicles and Penetration Enhancers on the Permeation of Cinnarizine Through the Skin

Objectives: The aim of this study was to determine the influence of vehicles and penetration enhancers on the penetration and permeation of cinnarizine (CNZ) through the skin. Materials and Methods: Topical formulations based on hydrogel, o/w emulsion and oleaginous cream were prepared. After determination of physical properties of formulations, the penetration and permeation of CNZ through the stratum corneum and full-thickness skin was investigated by an ex vivo study. Results: The cumulative amount of CNZ permeated from the base hydrogel formulation was about 5 times higher than the base o/w emulsion and base oleaginous cream formulations. The incorporation of penetration enhancers to the base hydrogel and o/w emulsion formulations generally increased CNZ penetration through the skin. Transcutol® was confirmed to provide the highest penetration in the hydrogel formulation. Propylene glycol was found to be the most suitable penetration enhancer for CNZ in the oleaginous cream. Glycerol and oleic acid displayed the highest effect in the o/w emulsion. Conclusion: It was concluded that the hydrogel containing Transcutol® provided the highest penetration through the skin among all formulations and this formulation could be an alternative to the oral route in the treatment of Ménière's disease and motion sickness. Thus, the risk of systemic side effects caused by oral medication can be reduced or eliminated.

Development of monolithic matrix type transdermal patches containing cinnarizine: Physical characterization and permeation studies

To overcome the problems associated with bioavailability and systemic side effects of the drug by oral administration, monolithic matrix type transdermal patches containing cinnarizine (CNZ) were developed. For this purpose, films based on hydroxypropyl methylcellulose and polyvinylpyrrolidone as matrix-forming polymers were designed. Physical characteristics of transdermal films and drug-excipient compatibility were investigated. Factors affecting in vitro drug release and ex vivo skin penetration and permeation of the drug were studied. It was confirmed that films displayed sufficient flexibility and mechanical strength for application onto the skin for a long time period. Ex vivo penetration experiments gave satisfactory results for transdermal drug delivery through rat skin. The parameters determining good skin penetration were also evaluated. The highest drug permeation rate was obtained with incorporation of Transcutol® (0.102 mg/cm2/h) into the base CNZ formulation, followed by propylene glycol (0.063 mg/cm2/h), menthol (0.045 mg/cm2/h), and glycerin (0.021 mg/cm2/h) as penetration enhancers (p < 0.05). As a result, the developed transdermal patches of CNZ may introduce an alternative treatment for various conditions and diseases such as idiopathic urticarial vasculitis, Ménière's disease, motion sickness, nausea, and vertigo. Thus, the risk of systemic side effects caused by the drug can be reduced or eliminated

Preformulation, Characterization, and In Vitro Release Studies of Caffeine-Loaded Solid Lipid Nanoparticles.

Encapsulation of active agents in solid lipid nanoparticles (SLNs) is an alternative to other controlled release systems for topical delivery. In this study, caffeine was encapsulated in SLNs to produce a delivery system with controlled release. Caffeine-loaded SLNs (Caf-SLNs) were prepared using the double emulsion method with homogenization and ultrasonication. The characterization studies were performed using dynamic light scattering (DLS), zeta potential, scanning electron microscopy (SEM), and differential scanning calorimetry (DSC) analyses. The encapsulation efficiency tests were performed using UV spectrophotometry. In vitro release studies were conducted using a dialysis bag technique and high-performance liquid chromatography (HPLC) for the quantification of caffeine (Caf). The results from the DLS analysis showed that all formulations had a polydispersity index <0.3 with particle sizes <210 nm. The DSC and SEM results showed that Caf was dispersed in the SLNs. The encapsulation efficiency was 49.22%. The release studies indicated that after an initial burst at 3 min, the SLNs released Caf in a controlled manner over a 6-h period. Taken together, the SLNs can be used as a carrier for the topical delivery of Caf.

Therapeutic potential of drug delivery by means of lipid nanoparticles: reality or illusion?

BACKGROUND: Solid lipid nanoparticles (SLN) are colloidal drug carrier systems that contribute several properties required from a sophisticated drug delivery system for increasing drug bioavailability and providing effective therapy. Many advantages of SLN have been reported over traditional dosage forms and their colloidal counterparts in the studies since the early 1990s. They were optimized for oral drug delivery for the first time. The first SLN formulations were produced by reducing the particle size of solid lipid microparticles by spray congealing technique in the late 1980s. Then, studies have been continued investigating for their different administration routes else including parenteral, transdermal, ocular, nasal, respiratory etc. METHODS: Their foremost qualifications such as their biocompatible nature and high drug entrapment efficiency make them promising colloidal drug carrier systems for the effective treatment of serious disasters like genetic disorders and cancer. CONCLUSION: In this review, therapeutic potential of drug delivery of SLN and nanostructured lipid carriers (NLC, the second generation of SLN) are summarized considering researches and patents on their administration via different routes and their preparations in the pharmaceutical market.

Design, optimization and characterization of coenzyme Q10- and D-panthenyl triacetate-loaded liposomes.

Coenzyme Q10 (CoQ10) is a lipid-soluble molecule found naturally in many eukaryotic cells and is essential for electron transport chain and energy generation in mitochondria. D-Panthenyl triacetate (PTA) is an oil-soluble derivative of D-panthenol, which is essential for coenzyme A synthesis in the epithelium. Liposomal formulations that encapsulate both ingredients were prepared and optimized by applying response surface methodology for increased stability and skin penetration. The optimum formulation comprised 4.17 mg CoQ10, 4.22 mg PTA and 13.95 mg cholesterol per 100 mg of soy phosphatidylcholine. The encapsulation efficiency of the optimized formulation for CoQ10 and PTA was found to be 90.89%±3.61% and 87.84%±4.61%, respectively. Narrow size distribution was achieved with an average size of 161.6±3.6 nm, while a spherical and uniform shape was confirmed via scanning electron microscopy and transmission electron microscopy images. Cumulative release of 90.93% for PTA and 24.41% for CoQ10 was achieved after 24 hours of in vitro release study in sink conditions. Physical stability tests indicated that the optimized liposomes were suitable for storage at 4°C for at least 60 days. The results suggest that the optimized liposomal formulation would be a promising delivery system for both ingredients in various topical applications.

Optimization of piribedil mucoadhesive tablets for efficient therapy of Parkinson's disease: physical characterization and ex vivo drug permeation through buccal mucosa.

OBJECTIVE: The aim of this study was optimization of buccal piribedil (PR) mucoadhesive tablets to improve its low bioavailability and provide controlled release for the treatment of Parkinson's disease. METHODS: Buccal tablets were prepared by direct compression method using carbomer (CP), carboxymethyl cellulose (CMC), and hydroxypropyl methylcellulose (HPMC) as mucoadhesive polymers. Physical properties of powder mixtures and buccal tablets were evaluated. Physicochemical compatibility between ingredients was investigated with infrared spectroscopy and differential scanning calorimetry analysis. In vitro dissolution profiles and drug release kinetics of buccal tablets were investigated. Mucoadhesion and ex vivo permeation studies were performed using sheep buccal mucosa. RESULTS: Powder mixtures demonstrated sufficient flow properties and physical characteristics of all tablet formulations were within compendia limits. Tablet ingredients were absent of any chemical interactions. CP tablets displayed slower drug release compared to HPMC tablets with zero order release, while CMC tablets lost their integrity and released entire drug after 6 h following Higuchi model. All formulations displayed adequate mucoadhesion and steady state flux of PR through buccal mucosa were higher with HPMC compared to CP-containing tablets. CONCLUSION: Overall, HPMC was found to combine desired controlled release and mucoadhesion characteristics with sufficient pharmaceutical quality for optimization of buccal tablets. Piribedil mucoadhesive buccal tablets designed for the first time may introduce a new alternative for the treatment of Parkinson's disease.