Ocular Drug Delivery: a Comprehensive Review.

The human eye is a sophisticated organ with distinctive anatomy and physiology that hinders the passage of drugs into targeted ophthalmic sites. Effective topical administration is an interest of scientists for many decades. Their difficult mission is to prolong drug residence time and guarantee an appropriate ocular permeation. Several ocular obstacles oppose effective drug delivery such as precorneal, corneal, and blood-corneal barriers. Routes for ocular delivery include topical, intravitreal, intraocular, juxtascleral, subconjunctival, intracameral, and retrobulbar. More than 95% of marketed products exists in liquid state. However, other products could be in semi-solid (ointments and gels), solid state (powder, insert and lens), or mixed (in situ gel). Nowadays, attractiveness to nanotechnology-based carries is resulted from their capabilities to entrap both hydrophilic and lipophilic drugs, enhance ocular permeability, sustain residence time, improve drug stability, and augment bioavailability. Different in vitro, ex vivo, and in vivo characterization approaches help to predict the outcomes of the constructed nanocarriers. This review aims to clarify anatomy of the eye, various ocular diseases, and obstacles to ocular delivery. Moreover, it studies the advantages and drawbacks of different ocular routes of administration and dosage forms. This review also discusses different nanostructured platforms and their characterization approaches. Strategies to enhance ocular bioavailability are also explained. Finally, recent advances in ocular delivery are described.

Digenic inheritance of IL-36RA and SEC61A1 mutations underlies generalized pustular psoriasis with hypogammaglobulinemia.

We report a female patient presenting with generalized pustular psoriasis and hypogammaglobulinemia due to digenic mutations in IL-36RA and SEC61A1. The patient presented with recurrent fevers, elevated inflammatory markers, hepatosplenomegaly, and recurrent sinopulmonary infections in the context of hypogammaglobulinemia which improved on immunoglobulin replacement. This report demonstrates how digenic inheritance leads to complex phenotypes, and illustrates the importance of following an unbiased approach to identifying variants, especially in patients with atypical clinical presentations.

Protective effect of rutin and ß-cyclodextrin against hepatotoxicity and nephrotoxicity induced by lambda-cyhalothrin in Wistar rats: biochemical, pathological indices and molecular analysis.

BACKGROUND: This study aimed to assess hepatotoxicity and nephrotoxicity of Lambda-cyhalothrin (LCT) and the protective effect of rutin alone and in combination with ß-cyclodextrin (ß-CD). MATERIALS AND METHODS: Male Wistar rats were divided into five groups: Group 1: was used as a control and received a standard diet and water. Group 2, 3, 4 and 5 were orally administered with LCT (7.6 mg/kg body weight), rutin (200 mg/kg body weight) LCT and rutin (at the same doses as in Group 2 and Group 3), and LCT and a mixture of rutin with ß-CD (400 mg/kg body weight), respectively. All experimental animals were orally gavaged 5 days/week for 60 days. RESULTS: Our data revealed that LCT-induced liver and kidney injuries were related to the up-regulated expression of TNF-α and down-regulated expression of NRF-2 genes mRNA, whereas these effects were reversed with rutin treatment. LCT-induced oxidative stress altered the histological picture, and the hematological and biochemical parameters. CONCLUSION: Treatment with a rutin-ß-CD complex had preventive potential against LCT via suppression of oxidative stress and augmentation of the antioxidant defense system.

Effect of Formulation Variables and Gamma Sterilization on Transcorneal Permeation and Stability of Proniosomal Gels as Ocular Platforms for Antiglaucomal Drug.

This study aims to evaluate the effect of different formulation variables (surfactant type and HLB value) adopting full factorial design (51. 21) using coacervation phase technique on in vitro characterization of dorzolamide hydrochloride (DZ)-loaded proniosomal gels, namely, entrapment efficiency percentage (EE%), vesicle size distribution, polydispersion index (PDI), and in vitro DZ release. The optimum formula F2 with a desirability value of 0.937 composed of 40 mg DZ, 500 mg span 60, 500 mg of L-α-Lethicin, and 55.5 mg cholesterol showing EE% of 84.5 ± 1.5%, PS of 189.5 ± 35.76 nm with PDI 0.8 ± 0.28 and 58.51% ± 1.00 of DZ released after 8 h was further evaluated using differential scanning calorimetry (DSC) and transmission electron microscopy (TEM). The effect of gamma sterilization on transcorneal permeation and stability of DZ from the selected formulation (F2) revealed that F2 was significantly tolerable, stable, and competent to corneal permeation confirmed by histological examination, confocal laser microscopy, and intraocular pressure (IOP) measurement. Significant corneal bioavailability was attained from formula F2 (370.6 mg. h/m) compared to the market product Trusopt® eye drops (92.59 mg. h/ml) following IOP measurement, thereby proniosomal gels could be considered as tolerable and competent ocular platforms for improving the transcorneal permeation of DZ.

Adefovir dipivoxil loaded proliposomal powders with improved hepatoprotective activity: formulation, optimization, pharmacokinetic, and biodistribution studies.

The present study aimed to prepare proliposomal formulae for improving the oral bioavailability of adefovir dipivoxil (AD), a nucleoside reverse transcriptase inhibitor effective against hepatitis B virus (HBV). The prepared proliposomal formulae were characterized for entrapment efficiency (E.E.%), vesicle size and in vitro drug release after reconstitution to conventional liposomes. The optimized formula (F9) with a maximum desirability value of 0.858 was selected having E.E.% of 71 ± 3.3% with an average vesicle size of 164.6 ± 5 nm. Moreover, the crystallization of AD within the optimized formula investigated via powder X-ray diffraction (XRD) and differential scanning calorimetry (DSC) confirmed the presence of the drug in an amorphous state within the lipid vesicles with enhanced stability over a storage period of 12 months. Thioacetamide-induced liver damage in rats evidenced by elevated liver enzymes was significantly improved after treatment with the optimum formula. Pharmacokinetic and biodistribution studies of formula F9 showed a higher accumulation of AD in the liver with enhanced bioavailability compared to AD suspension which highlights its potential advantage for an effective treatment of chronic HBV. Hence, proliposomal drug delivery is considered as a better choice for the oral delivery of AD.

Comparative Study Between Different Ready-Made Orally Disintegrating Platforms for the Formulation of Sumatriptan Succinate Sublingual Tablets.

Sumatriptan succinate (SS) is a selective serotonin receptor agonist used for the treatment of migraine attacks, suffering from extensive first-pass metabolism and low oral bioavailability (∼14%). The aim of this work is to compare the performance of different ready-made co-processed platforms (Pharmaburst®, Prosolv ODT®, Starlac®, Pearlitol Flash®, or Ludiflash®) in the formulation of SS sublingual orodispersible tablets (ODTs) using direct compression technique. The prepared SS ODT formulae were evaluated regarding hardness, friability, simulated wetting time, and in vitro disintegration and dissolution tests. Different mucoadhesive polymers-HPMC K4M, Carbopol®, chitosan, or Polyox®-were tested aiming to increase the residence time in the sublingual area. A pharmacokinetic study on healthy human volunteers was performed, using LC/MS/MS assay, to compare the optimum sublingual formula (Ph25/HPMC) with the conventional oral tablet Imitrex®. Results showed that tablets prepared using Pharmaburst® had significantly (p < 0.05) the lowest simulated wetting and in vitro disintegration times of 17.17 and 23.50 s, respectively, with Q 5 min of 83.62%. HPMC showed a significant (p < 0.05) increase in the residence time from 48.44 to 183.76 s. The relative bioavailability was found to be equal to 132.34% relative to the oral tablet Imitrex®. In conclusion, Pharmaburst® was chosen as the optimum ready-made co-processed platform that can be successfully used in the preparation of SS sublingual tablets for the rapid relief of migraine attacks.

Sumatriptan succinate sublingual fast dissolving thin films: formulation and in vitro/in vivo evaluation.

Sumatriptan succinate (SS) is a 5-HT1 receptor agonist used in the treatment of migraine having poor bioavailability (15%) due to its extensive first-pass effect. The aim of this work was to prepare SS sublingual fast dissolving thin films (SFDTFs) allowing the drug to directly enter the systemic circulation and bypassing the first-pass metabolism. Plain thin films were prepared using solvent casting technique adopting 2(3) × 3 factorial design to study the effect of polymer and plasticizer type and concentration on mechanical properties and in vitro disintegration time of the plain prepared films using Design-Expert®. Medicated films were prepared after addition of 35 mg SS to each of the two selected plain formulae (F6 and F7) having desirability values above 0.9 showing the values of: 0.038, 0.039 kgf/mm(2) and 156.24, 164.16% and 0.0248, 0.0240 kgf/mm(2) as tensile strength, percent elongation and elastic modulus, respectively. PVP K30 was efficient as crystallization inhibitor in retarding SS crystallization. Pharmacokinetic study of the optimum formula F7 (PVP K30:SS (1:1 w/w)) in healthy human volunteers using LC/MS/MS revealed a shorter tmax (0.25 h) compared to Imitrex® tablet 25 mg (2 h) which is considered promising especially for the rapid relief of acute migraine attacks.

Effect of formulation variables on design, in vitro evaluation of valsartan SNEDDS and estimation of its antioxidant effect in adrenaline-induced acute myocardial infarction in rats.

Valsartan is a specific angiotensin II antagonist used for the treatment of hypertension. It suffers from low aqueous solubility and high variability in its absorption after oral administration. The aim of this study was to improve the dissolution and thereby the bioavailability of Valsartan through the development of self nano-emulsifying drug delivery systems. Four ternary phase diagrams were constructed to identify the self-emulsification region of Capmul® MCM, Labrafil® M1944, Capryol™ 90 and Labrafac® PG together with Cremophore® RH 40 and Transcutol™ HP as oil, surfactant and co-surfactant, respectively. The effect of oil type, oil and surfactant concentration on droplet size and in vitro Valsartan dissolution were studied. The protective effect of the optimum formula F5 in adrenaline-induced oxidative stress in rats during myocardial infarction was determined. Formula F5 exhibited globule size of (13.95 nm) with 76.07% ± 1.10 of Valsartan dissolved after five minutes compared to Disartan 80 mg capsules (13.43%). Results revealed a significant reduction (p < 0.05) in serum aspartate transaminase, creatine kinase myocardial band and malondialdehyde levels, while a significant increase (p < 0.05) in serum glutathione in F5. Therefore, self nano-emulsifying drug delivery systems could be considered as a promising approach to improve the dissolution and thereby the bioavailability of Valsartan.

A comprehensive review on recent nanosystems for enhancing antifungal activity of fenticonazole nitrate from different routes of administration.

This review aims to comprehensively highlight the recent nanosystems enclosing Fenticonazole nitrate (FTN) and to compare between them regarding preparation techniques, studied factors and responses. Moreover, the optimum formulae were compared in terms of in vitro, ex vivo and in vivo studies in order to detect the best formula. FTN is a potent antifungal imidazole compound that had been used for treatment of many dangerous fungal infections affecting eye, skin or vagina. FTN had been incorporated in various innovative nanosystems in the recent years in order to achieve significant recovery such as olaminosomes, novasomes, cerosomes, terpesomes and trans-novasomes. These nanosystems were formulated by various techniques (ethanol injection or thin film hydration) utilizing different statistical designs (Box-Behnken, central composite, full factorial and D-optimal). Different factors were studied in each nanosystem regarding its composition as surfactant concentrations, surfactant type, amount of oleic acid, cholesterol, oleylamine, ceramide, sodium deoxycholate, terpene concentration and ethanol concentration. Numerous responses were studied such as percent entrapment efficiency (EE%), particle size (PS), poly-dispersity index (PDI), zeta potential (ZP), and in vitro drug release. Selection of the optimum formula was based on numerical optimization accomplished by Design-Expert® software taking in consideration the largest EE %, ZP (as absolute value) and in vitro drug release and lowest PS and PDI. In vitro comparisons were done employing different techniques such as Transmission electron microscopy, pH determination, effect of gamma sterilization, elasticity evaluation and docking study. In addition to, ex vivo permeation, in vivo irritancy test, histopathological, antifungal activity and Kinetic study.

Chitosan Surface-Modified PLGA Nanoparticles Loaded with Cranberry Powder Extract as a Potential Oral Delivery Platform for Targeting Colon Cancer Cells.

Nutraceutical cranberry powder extract (CBPE) has distinct polyphenols inhibiting colon cancer growth and proliferation. However, its oral therapeutic efficacy is hindered because of its low permeability. This study aims to formulate chitosan surface-modified PLGA nanoparticles (CS-PLGA NPs) for encapsulating CBPE and modulating its release rate, permeation, cell targeting, and, therefore, its cytotoxicity. A full 23 factorial design is employed to scrutinize the effect of lactide/glycolide ratio, PLGA weight, and stabilizer concentrations on entrapment efficiency percentage (EE%), particle size (PS), polydispersity index (PDI), and zeta potential (ZP). The optimum formula (F4) shows spherical particles with a relatively high EE% (72.30 ± 2.86%), an appropriate size of 370.10 ± 10.31 nm, PDI; 0.398 ± 0.001, and ZP; -5.40 ± 0.21 mV. Alongside the ATR-FTIR outcomes, the chitosan surface-modified formula (CS-F4) demonstrates a significant increase in particle size (417.67 ± 6.77 nm) and a shift from negative to positive zeta potential (+21.63 ± 2.46 mV), confirming the efficiency of surface modification with chitosan. The intestinal permeability of F4 and CS-F4 is significantly increased by 2.19- and 3.10-fold, respectively, compared to the CBPE solution, with the permeability coefficient (Papp) being 2.05 × 10-4 cm/min and 2.91 × 10-4 cm/min, for F4 and CS-F4, respectively, compared to the CBPE solution, 9.36 × 10-5 cm/min. Moreover, CS-F4 evidences significant caspase-3 protein level expression stimulation and significant inhibition of vascular endothelial growth factor (VEGF) and signal transducer and activator of transcription-3 (STAT-3) protein expression levels, confirming the superiority of CS-F4 for targeting HT-29 cells. Briefly, CS-PLGA NPs could be regarded as a prosperous delivery system of CBPE with enhanced permeation, cell targeting, and antitumor efficacy.

Pronounced capping effect of olaminosomes as nanostructured platforms in ocular candidiasis management.

The aim of this study was to formulate and boost ocular targeting of Fenticonazole Nitrate (FTN)-loaded olaminosomes in order to improve drug corneal permeation and candidiasis treatment. Olaminosomes were formulated by ethanol injection technique applying a central composite design. The independent variables were: span 80 amount (mg) (A), oleylamine concentration (mg%) (B) and oleic acid: drug ratio (C). The dependent responses were: percent entrapment efficiency (EE %), particle size (PS), poly-dispersity index (PDI), zeta potential (ZP) and in vitro drug release after 10 hours (Q10h). Numerical optimization by Design-Expert® software was adopted to select the optimum formula. This formula was chosen based on highest EE %, ZP (as absolute value) and Q10h and lowest PS and PDI. The optimum formula was subjected to further in vitro characterization via Differential scanning calorimetry, Transmission electron microscopy, Fourier transform infrared spectroscopy, pH determination, effect of storage, influence of terminal sterilization, detection of Minimal Inhibitory Concentration and ex vivo corneal penetration analysis. Safety and antifungal activity of the optimum formula were tested through various in vivo studies like ocular irritancy, corneal tolerance, corneal uptake and susceptibility test. The optimum formula with the maximum desirability value (0.972) revealed EE% (84.24%), PS (117.55 nm), ZP (-74.85 mV) and Q10h (91.26%) respectively. The optimum formula demonstrated ocular tolerance with enhanced corneal penetration behavior (428.66 µg/cm2) and boosted antifungal activity (56.13%) compared to FTN suspension (174.66 µg/cm2 and 30.83%). The previous results ensured the ability of olaminosomes to enhance the corneal penetration and antifungal efficacy of Fenticonazole Nitrate.

Corneal targeted fenticonazole nitrate-loaded novasomes for the management of ocular candidiasis: Preparation, in vitro characterization, ex vivo and in vivo assessments.

The purpose of this manuscript was to develop and optimize Fenticonazole Nitrate (FTN)-loaded novasomes aiming to enhance drug corneal penetration and to improve its antifungal activity. Ethanol injection was used to formulate FTN-loaded novasomes adopting a central composite design. The researched factors were: stearic acid concentration (g%) (A), span 80: drug ratio (B) and cholesterol amount (mg) (C), and their effects on percent entrapment efficiency (EE%), particle size (PS), poly-dispersity index (PDI), zeta potential (ZP), and in vitro drug release after 8 hours (Q8h) were studied. Numerical optimization by Design-Expert® software was employed to select the optimum formula in respect to highest EE%, ZP (as absolute value), and Q8h >80% and lowest PS and PDI. Additional evaluation of the optimum formula was accomplished by short term stability study, effect of gamma sterilization, determination of Minimal Inhibitory Concentration and ex vivo corneal permeation study. The in vivo evaluation of the optimum formula was done to ensure its safety via in vivo ocular irritancy and in vivo corneal tolerance studies. Also, the efficacy was confirmed through in vivo corneal uptake study and susceptibility test. The optimum formula with the highest desirability value (0.738) showed EE% (94.31%), PS (197.05 nm), ZP (-66.95 mV) and Q8h (85.33%). It revealed to be safe, with augmented corneal permeation (527.98 µg/cm2) that leads to higher antifungal activity. The above results confirmed the validity of novasomes to improve the corneal permeation and antifungal activity of Fenticonazole Nitrate.

"TPGS surface modified bilosomes as boosting cytotoxic oral delivery systems of curcumin against doxorubicin resistant MCF-7 breast cancer cells".

The goal of this work was to design nude bilosomes (Bil) and D-alpha-tocopheryl polyethylene glycol succinate (TPGS) surface coated bilosomes as an oral delivery platform for improving the antitumor activity and poor oral permeability of Curcumin (CUR). Twelve different formulae were acquired from 31.22 factorial analysis considering different independent variables: bile salt type; Sodium taurocholate (STC) or Sodium cholate (SC) and weight percent; 1% or 5 % W/W, both at 2 levels respectively, while Span 60:Cholesterol ratio at 3 levels (1:1, 5:1, 9:1). Following optimization, the selected optimum formula was picked up based on the favorable minimum particle size (187.2 ± 2.2 nm), maximum zeta potential value (-41.3 ± 2.2 mV) and maximum entrapment efficiency (93.4 ± 5.1%) which was further coated with TPGS. The mean fluorescence intensity (MFI) of CUR permeated from the optimum TPGS-F7 and CUR-Bil (F7) formulae exhibited 6.6 and 3.4 folds increase respectively adopting ex-vivo duodenal permeation assay relative to that of CUR suspension. Moreover, the cellular uptake efficiency via the established Caco-2 cells revealed that the uptake of CUR was 61.9 ± 5.3% and 34.76 ± 0.61% from TPGS-F7 and CUR-Bil (F7) relative to the uptake efficiency of CUR suspension (7.4 ± 2.12%). Coherently, TPGS-CUR-Bil showed excellent response expressed in dominant reduction in IC50 value (2.8 ± 0.07 µg/ml) against multidrug resistant (MDR) tumors following 48 h incubation of Doxorubicin Resistant Breast Cancer (MCF-7/ADR) cell lines.

Brain targeting efficiency of intranasal clozapine-loaded mixed micelles following radio labeling with Technetium-99m.

The research objective is to design intranasal (IN) brain targeted CLZ-loaded polymeric nanomicellar systems (PNMS) aiming to improve central systemic CLZ bioavailability. Direct equilibrium method was used to prepare CLZ-PNMS using two hydrophobic poloxamines; Tetronic® 904 (T904) and Tetronic® 701 (T701) and one hydrophilic poloxamer; Synperonic® PE/F127 (F127). Optimization is based on higher percent transmittance, solubilizing efficiency, and in vitro release after 24 h with smaller particle size was achieved using Design-Expert® software. The optimized formula was further evaluated via TEM, ex vivo nasal permeation in addition to in vivo biodistribution using radiolabeling technique of the optimized formula by Technetium-99m (99mTc). The optimized formula M5 has small size (217 nm) with relative high percentage of transmittance (97.72%) and high solubilization efficacy of 60.15-fold following 92.79% of CLZ released after 24 h. Ex vivo nasal permeation showed higher flux of 36.62 µg/cm2.h compared to 7.324 µg/cm2.h for CLZ suspension with no histological irritation. In vivo biodistribution results showed higher values of radioactivity percentage of the labeled optimized formula (99mTc-M5) in brain and brain/blood ratio following IN administration of 99mTc-M5 complex which were greater than their corresponding values following intravenous route. It is obvious that nasal delivery of CLZ-PNMS could be a promising way to improve central systemic CLZ bioavailability.

Trimetazidine Dihydrochloride Pulsatile-Release Tablets for the Treatment of Morning Anginal Symptoms: Dual Optimization, Characterization and Pharmacokinetic Evaluation.

OBJECTIVE: This research work aimed to target the early morning peak symptoms of chronic stable angina through formulating antianginal drug, Trimetazidine (TMZ) in a pulsatile-release tablet. METHODS: The core formulae were optimized using 22 .31 factorial design to minimize disintegration time (DT) and maximize drug release after 5 minutes (Q5min). Different ratios of Eudragit S100 and Eudragit L100 were used as a coating mixture for the selected core with or without a second coating layer of hydroxypropyl methylcellulose (HPMC E50). The different formulation variables were statistically optimized for their effect on lag time and drug release after 7 hours (Q7h) using BoxBehnken design. The optimized formula (PO) was subjected to stability study and pharmacokinetic assessment on New Zealand rabbits. RESULTS: The optimal core (F8) was found to have 1.76 min disintegration time and 61.45% Q5min PO showed a lag time of 6.17 h with 94.80% Q7h and retained good stability over three months. The pharmacokinetics study confirmed the pulsatile-release pattern with Cmax of 206.19 ng/ml at 5.33 h (Tmax) and 95.85% relative bioavailability compared to TMZ solution. CONCLUSION: Overall pulsatile-release tablets of TMZ successfully released the drug after a desirable lag time, providing a promising approach for early morning anginal symptoms relief.

Stabilized oral nanostructured lipid carriers of Adefovir Dipivoxil as a potential liver targeting: Estimation of liver function panel and uptake following intravenous injection of radioiodinated indicator.

PURPOSE: Adefovir dipivoxil (AD), a nucleoside reverse transcriptase inhibitor is effective against Hepatitis B virus. Its poor oral bioavailability leads to frequent administration causing severe adverse effects. Thereby the entrapment of AD within lipid nanoparticulate systems is a way of increasing AD oral bioavailability as a result of improving intestinal permeability with efficient liver-targeted delivery together with higher drug stability during storage. METHODS: AD-loaded nanostructured lipid carriers (AD-NLCs) were prepared via solvent emulsification diffusion technique adopting 24 full factorial design to study the effect of lipid percentage, presence of egg yolk lecithin, surfactant type and percentage on entrapment efficiency (E.E.%), particle size and percent in-vitro drug released after 8 h (Q8hrs). RESULTS: Formula (F12) showed E.E.% of 90.5 ± 0.2%, vesicle size of 240.2 ± 2.5 nm and Q8hrs of 58.55 ± 9.4% was selected as the optimum formula with desirability value of 0.757 based on highest EE%, lowest P.S. and Q8hrs. Further evaluation of the optimized formula using radioiodinated rose bengal (RIRB) in thioacetamide induced liver damage in Swiss Albino mice revealed a higher liver uptake of 22 ± 0.01% ID/g (percent injected dose/g organ) and liver uptake/Blood (T/B) ratio of 2.22 ± 0.067 post 2 h of I.V injection of RIRB compared to 9 ± 0.01% ID/g and 0.64 ± 0.017 in untreated group, respectively. CONCLUSION: NLCs could be successfully used as oral drug delivery carriers of the antiviral drug Adefovir Dipivoxil to the liver with higher stability and oral bioavailability. Graphical abstract.

Superhydrophobic Substrates for Ultrahigh Encapsulation of Hydrophilic Drug into Controlled-Release Polyelectrolyte Complex Beads: Statistical Optimization and In Vivo Evaluation.

: In this work, ultrahigh drug-loaded chitosan (Ch)/K-carrageenan (Kc) polyelectrolyte complex (PEC) beads were formed in situ by cross-linking in a glutaraldehyde-saturated atmosphere and were prepared on superhydrophobic substrates fabricated by spraying glass surfaces with ready-made spray for domestic use (NeverWet®). Verapamil hydrochloride (VP), a highly hydrophilic drug with a short biological half-life, was incorporated into a series of Ch-based and/or Ch/Kc-PEC-based beads to control its release profile in vivo. The formulation of VP-loaded beads was optimized using stepwise statistical designs based on a prespecified criterion. Several characteristics of the prepared beads, such as entrapment efficiency (EE%), in vitro drug release, swelling ratio, size and surface microstructure as well as molecular interactions between the drug and formulation ingredients, were investigated. In vivo pharmacokinetic (PK) studies were carried out using the rabbit model to study the ability of the optimized VP-loaded beads to control the absorption rate of VP. Results revealed that the prepared superhydrophobic substrates were able to fabricate VP-loaded beads with extremely high EE exceeding 90% w/w compared to only 27.80% when using conventional ionotropic gelation technique. PK results showed that the rate of VP absorption was well controlled following oral administration of the optimized beads to six rabbits compared to a marketed VP immediate release (IR) tablet, as evidenced by a 2.2-fold increase in mean residence time (MRT) and 5.24-fold extension in half value duration (HVD) over the marketed product without any observed reduction in the relative oral bioavailability.

Prevalence of Congenital Ocular Anomalies among Children with Genetic Disorders: An Egyptian Study.

PURPOSE: To assess the pattern and frequency of occurrence of ocular anomalies among other genetic disorders in Egypt. METHODS: This is a cross-sectional study of 2500 cases presenting with genetic disorders. Cases were recruited from the clinical genetics department of the National Research Centre (NRC) over a four-year period between January 2011 and December 2014. Ophthalmological examination of the cases was performed in the pediatric ophthalmology department of Cairo University Hospitals. RESULTS: Out of 2500 cases with congenital disorders, 2.4% suffered one or more ocular anomalies with a male to female ratio of 1.7:1. Consanguinity was reported in 76.7% and family history was positive in 35% of ocular cases. The most common ocular anomalies were congenital cataract, retinal dystrophies, glaucoma, and retinoblastoma in order of frequency. Chromosomal aberrations were detected in two retinoblastoma cases and in one case of charge association with cataract and iris coloboma. A truncating mutation in exon 8 of OCRL1 was reported in a case of Lowe syndrome with cataract. A total of 51.7% of ocular cases were non-isolated (associated with other genetic disorders). CONCLUSION: In Egypt, ocular genetic disorders are not uncommon among other genetic disorders. Consanguinity is high, suggesting high incidence of autosomal recessive inheritance of genetic disorders with an ocular component. Proper systemic assessment of all cases with ocular anomalies is a necessity due to the high percentage of non-isolated ocular anomalies. Genetic counseling of parents would help in reducing recurrence rates through prenatal diagnosis whenever possible.

Ultrahigh verapamil-loaded controlled release polymeric beads using superamphiphobic substrate: D-optimal statistical design, in vitro and in vivo performance.

Controlled-release multiparticulate systems of hydrophilic drugs usually suffer from poor encapsulation and rapid-release rate. In the present study, ultra-high loaded controlled release polymeric beads containing verapamil hydrochloride (VP) as hydrophilic model drug were efficiently prepared using superamphiphobic substrates aiming to improve patient compliance by reducing dosing frequency. Superamphiphobic substrates were fabricated using clean aluminum sheets etched with ammonia solution and were treated with 1.5% (w/v) perfluorodecyltriethoxysilane (PFDTS) alcoholic solution. The effect of the main polymer type (lactide/glycolide (PLGA) 5004A, PLGA 5010, and polycaprolactone (PCL)), copolymer (Eudragit RS100) content together with the effect of drug load on encapsulation efficiency (EE%) and in vitro drug release was statistically studied and optimized via D-optimal statistical design. In vivo pharmacokinetic study was carried out to compare the optimized system relative to the market product (Isoptin®). Results revealed that superamphiphobic substrates were successfully prepared showing a rough micro-sized hierarchical structured surface upon observing with scanning electron microscope and were confirmed by high contact angles of 151.60 ± 2.42 and 142.80°±05.23° for water and olive oil, respectively. The fabricated VP-loaded beads showed extremely high encapsulation efficiency exceeding 92.31% w/w. All the prepared systems exhibited a controlled release behavior with Q12 h ranging between 5.46 and 95.90%w/w. The optimized VP-loaded system composed of 150 mg (1.5% w/v) PCL without Eudragit RS100 together with 160 mg VP showed 2.7-folds mean residence time compared to the market product allowing once daily administration instead of three times per day.

Ocular ketoconazole-loaded proniosomal gels: formulation, ex vivo corneal permeation and in vivo studies.

CONTEXT: Vesicular drug carriers for ocular delivery have gained a real potential. Proniosomal gels as ocular drug carriers have been proven to be an effective way to improve bioavailability and patient compliance. OBJECTIVE: Formulation and in vitro/ex vivo/in vivo characterization of ketoconazole (KET)-loaded proniosomal gels for the treatment of ocular keratitis. MATERIALS AND METHODS: The effect of formulation variables; HLB value, type and concentration of non-ionic surfactants (Tweens, Spans, Brijs and Pluronics) with or without lecithin on the entrapment efficiency (EE%), vesicle size and in vitro KET release was evaluated. An ex vivo corneal permeation study to determine the level of KET in the external eye tissue of albino rabbits and an in vivo assessment of the level of KET in the aqueous humors were performed. RESULTS AND DISCUSSION: In vivo evaluation showed an increase in bioavailability up to 20-folds from the optimum KET proniosomal gel formula in the aqueous humor compared to drug suspension (KET-SP). The selected formulae were composed of spans being hydrophobic suggesting the potential use of a more hydrophobic surfactant as Span during the formulation of formulae. Factors that stabilize the vesicle membrane and increase the entrapment efficiency of KET (namely low HLB, long alkyl chain, high phase transition temperature) slowed down the release profile. CONCLUSIONS: Proniosomal gels as drug delivery carriers were proven to be a promising approach to increase corneal contact and permeation as well as retention time in the eye resulting in a sustained action and enhanced bioavailability.