Once-daily propranolol extended-release tablet dosage form: formulation design and in vitro/in vivo investigation

Mannitol-coated hydroxypropyl methylcellulose as an alternative directly compressible controlled release excipient

One of the most common forms of controlled release technology for oral drug delivery comprises an active ingredient dispersed in a hydrophilic matrix forming polymer such as hydroxypropyl methylcellulose (HPMC), which is tableted via direct compression. However, HPMC may pose problems in direct compression due to its poor flowability. Hence, mannitol syrup was spray-coated over fluidized HPMC particles to produce co-processed HPMC-mannitol at ratios of 20:80, 50:50, and 70:30. Particles of pure HPMC, co-processed HPMC-mannitol, and their respective physical mixtures were evaluated for powder flowability, compression profiles, and controlled release performance. It was found that co-processed HPMC-mannitol consisted of particles with improved flow compared to pure HPMC particles. Sufficiently strong tablets of >2 MPa could be produced at moderate to high compression forces of 150-200 MPa. The dissolution profile could be tuned to obtain desired release profiles by altering HPMC-mannitol ratios. Co-processed HPMC-mannitol offers an interesting addition to the formulator's toolbox in the design of controlled release formulations for direct compression.

Box Behnken optimization of cubosomes for enhancing the anticancer activity of metformin: Design, characterization, and in-vitro cell proliferation assay on MDA-MB-231 breast and LOVO colon cancer cell lines

This study aimed to formulate and statistically optimize cubosomal formulations of metformin (MTF) to enhance its breast anticancer activity. A Box Behnken design was employed using Design-Expert® software. The formulation variables were glyceryl monooleate concentration (GMO) w/w%, Pluronic F-127 concentration (PF127) w/w% and Tween 80 concentration w/w% whereas Entrapment efficiency (EE%), Vesicles' size (VS) and Zeta potential (ZP) were set as the dependent responses. The design expert software was used to perform the process of optimization numerically. X ray diffraction (XRD), Transmission electron microscope (TEM), in-vitro release study, short-term stability study, and in in-vitro cell proliferation assay on the MDA-MB-231 breast cancer and LOVO cancer cell lines were used to validate the optimized cubosomal formulation. The optimized formulation had a composition of 4.35616 (w/w%) GMO, 5 (w/w%) PF127 and 7.444E-6 (w/w%) Tween 80 with a desirability of 0.733. The predicted values for EE%, VS and ZP were 78.0592%, 307.273 nm and - 26.8275 mV, respectively. The validation process carried out on the optimized formula revealed that there were less than a 5% variance from the predicted responses. The XRD thermograms showed that MTF was encapsulated inside the cubosomal vesicles. TEM images of the optimized MTF cubosomal formulation showed spherical non-aggregated nanovesicles. Moreover, it revealed a sustained release profile of MTF in comparison to the MTF solution. Stability studies indicated that optimum cubosomal formulation was stable for thirty days. Cytotoxicity of the optimized cubosomal formulation was enhanced on the MDA-MB-231 breast and LOVO cancer cell lines compared to MTF solution even at lower concentrations. However, it showed superior cytotoxic effect on breast cancer cell line. So, cubosomes could be considered a promising carrier of MTF to treat breast and colon cancers.

Microsponge-derived mini tablets loaded with immunosuppressive agents: Pharmacokinetic investigation in human volunteers, cell viability and IVIVC correlation

Sirolimus, a potent immunosuppressant, has been demonstrated to have remarkable activity in inhibiting allograft rejection in transplantation. The objective of the study was to fabricate microsponge mini tablets with enhanced solubility and bioavailability. β-Cyclodextrin and NEOCEL C91 were selected to prepare the microsponges (SLM-M) to improve the stability and solubility of sirolimus. The current study involved the quasi emulsion-solvent diffusion technique to design sirolimus-loaded microsponges that were further compressed into mini tablets 4 mm in diameter. Solid-state characterization, dissolution at different pH values, stability, and pharmacokinetic profiles with IVIVC data were analyzed in humans. Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), and X-ray diffraction (XRD) were used to characterize the formulations, and high-performance liquid chromatography (HPLC) was used to assess the drug stability of the compressed microsponge minitablets. The API changed from the crystalline state to an amorphous state, as shown by XRD and DSC. The compressed mini tablets showed a 4-fold enhancement in the drug dissolution profile. A toxicology investigation suggested that mini tablets were safe. In humans, the bioavailability of sirolimus compressed mini tablets from SLM-M was significantly improved. The results suggest that mini tablets prepared with β-cyclodextrin and NEOCEL C91 by a quasi emulsion-solvent diffusion process might be an alternative way to improve the bioavailability of sirolimus. In addition, the manufacturing process is easily scalable for the commercialization of drugs to market.

Development of a Novel Bilosomal System for Improved Oral Bioavailability of Sertraline Hydrochloride: Formulation Design, In Vitro Characterization, and Ex Vivo and In Vivo Studies

This study was proposed to develop an optimized sertraline hydrochloride (SER)-loaded bilosomal system and evaluate its potential for enhancement of drug oral bioavailability. A full 2³ factorial design was used to prepare SER-loaded bilosomal dispersions by thin film hydration using span 60, cholesterol (CHL), and sodium deoxycholate (SDC). The investigated factors included the total concentration of span 60 and CHL (X₁), span 60:CHL molar ratio (X₂), and SER:SDC molar ratio (X₃). The studied responses were entrapment efficiency (EE%) (Y₁), zeta potential (Y₂), particle size (Y₃), and in vitro % drug released at 2 (Y₄), 8 (Y₅), and 24 h (Y₆). The selected optimal bilosomal dispersion (N1) composition was 0.5% w/v (X₁), 1:1 (X₂), and 1:2 (X₃). Then, N1 was freeze dried into FDN1 that compared with pure SER for in vitro drug release, ex vivo permeation through rabbit intestine, and in vivo absorption in rats. Moreover, storage effect on FDN1 over 3 months was assessed. The optimal dispersion (N1) showed 68 ± 0.7% entrapment efficiency, - 41 ± 0.78 mV zeta potential, and 377 ± 19 nm particle size. The freeze-dried form (FDN1) showed less % drug released in simulated gastric fluids with remarkable sustained SER release up to 24 h compared to pure SER. Moreover, FDN1 showed good stability, fivefold enhancement in SER permeation through rabbit intestine, and 222% bioavailability enhancement in rats' in vivo absorption study compared to pure SER. The SER-loaded bilosomal system (FDN1) could improve SER oral bioavailability with minimization of gastrointestinal side effects.

Lipid-based nano-formulation platform for eplerenone oral delivery as a potential treatment of chronic central serous chorioretinopathy: in-vitro optimization and ex-vivo assessment

PURPOSE

Eplerenone (EPL) is a selective mineralocorticoid receptor antagonist used for treatment of chronic central serous chorioretinopathy which characterized by accumulation of subretinal fluid causing a localized area of retinal detachment. unfortunately, EPL suffers from poor oral bioavailability due to poor aqueous solubility in addition to high hepatic first pass metabolism.

METHOD

Aiming to improve its oral bioavailability, EPL-loaded nanostructured lipid carriers (NLCs) were prepared by the emulsification solvent evaporation method and in-vitro evaluated for particle size (PS), polydispersity index (PDI), zeta potential (ZP), and entrapment efficiency (EE%). A D-optimal design was used for study the effect of liquid lipid to solid lipid ratio, surfactant type and percentage on PS, PDI, EE%, and for data optimization. The optimized EPL-loaded NLCs system was further evaluated using in-vitro drug release and ex-vivo permeation studies through rabbit intestine in comparison to EPL aqueous suspension. The physicochemical properties of the drug in the optimized system were further examined using FT-IR and X-ray diffraction studies.

RESULTS

The resultant NLCs showed small PS (100.85-346.60 nm), homogenous distribution (0.173-0.624), negatively charged particles (ZP -20.20 to -36.75 mV), in addition to EE% (34.31-70.64%). The optimized EPL-loaded NLCs system with a desirability value of 0.905 was suggested through the Design expert® software, containing liquid to solid lipid ratio (2:1) in presence of 0.43%w/v Pluronic® F127 as a surfactant. The optimized EPL-loaded NLCs system showed a PS of 134 nm and PDI of 0.31, in addition to high EE% (76 ± 6.56%w/w), and ZP (-32.37 mV). The ex-vivo permeation study showed two-fold higher drug permeation through rabbit intestine compared to that from the aqueous drug suspension after 24 h, confirming the ability of optimized EPL-loaded NLCs system as successful oral targeting delivery carrier.

CONCLUSION

Our results pave the way for a new oral nanotherapeutic approach toward CSCR treatment. In-vivo study is currently under investigation.

Fluoxetine hydrochloride loaded lipid polymer hybrid nanoparticles showed possible efficiency against SARS-CoV-2 infection

Up to date, there were no approved drugs against coronavirus (COVID-19) disease that dangerously affects global health and the economy. Repurposing the existing drugs would be a promising approach for COVID-19 management. The antidepressant drugs, selective serotonin reuptake inhibitors (SSRIs) class, have antiviral, anti-inflammatory, and anticoagulant effects, which makes them auspicious drugs for COVID 19 treatment. Therefore, this study aimed to predict the possible therapeutic activity of SSRIs against COVID-19. Firstly, molecular docking studies were performed to hypothesize the possible interaction of SSRIs to the Severe Acute Respiratory Syndrome coronavirus 2 (SARS-COV-2) main protease. Secondly, the candidate drug was loaded in lipid polymer hybrid (LPH) nanoparticles to enhance its activity. The studied SSRIs were Fluoxetine hydrochloride (FH), Atomoxteine, Paroxetine, Nisoxteine, Repoxteine RR, and Repoxteine SS. Interestingly, FH could effectively bind with SARS-COV-2 main protease via hydrogen bond formation with low binding energy (-6.7 kcal/mol). Moreover, the optimization of FH-LPH formulation achieved 65.1 ± 2.7% encapsulation efficiency, 10.3 ± 0.4% loading efficiency, 98.5 ± 3.5 nm particle size, and -10.5 ± 0.45 mV zeta potential. Additionally, it improved cellular internalization in a time-dependent manner with good biocompatibility on Human lung fibroblast (CCD-19Lu) cells. Therefore, the study suggested the potential activity of FH-LPH nanoparticles against the COVID-19 pandemic.

Combinatory Delivery of Etoposide and siCD47 in a Lipid Polymer Hybrid Delays Lung Tumor Growth in an Experimental Melanoma Lung Metastatic Model

This study investigated the feasibility of lipid polymer hybrid nanoparticles (LPH) as a platform for the combinatorial delivery of small interfering RNA (siRNA) and etoposide (Eto). Different Eto loaded LPH formulations (LPH _Eto ) are prepared. The optimized cationic LPH _Eto  with a particle size of 109.66 ± 5.17 nm and Eto entrapment efficiency (EE %) of 80.33 ± 2.55 is used to incorporate siRNA targeting CD47 (siCD47), a do not eat me marker on the surface of cancer cells. The siRNA-encapsulating LPH (LPH _siNEG-Eto ) has a particle size of 115.9 ± 4.11 nm and siRNA EE % of 63.54 ± 4.36 %. LPHs improved the cellular uptake of siRNA in a dose- and concentration-dependent manner. Enhanced cytotoxicity (3.8-fold higher than Eto solution) and high siRNA transfection efficiency (≈50 %) are obtained. An in vivo biodistribution study  showed a preferential uptake of the nanosystem into lung, liver, and spleen. In an experimental pseudo-metastatic B16F10 lung tumor model, a superior therapeutic outcome can be observed in mice treated with combinatory therapy. Immunological studies revealed elevated CD4+, CD8+ cells, and macrophages in the lung following combinatory treatment. The study suggests the potential of the current system for combinatory chemotherapy and immunotherapy for the treatment of lung cancer or lung metastasis.

Preparation of solid dispersion systems for enhanced dissolution of poorly water soluble diacerein: In-vitro evaluation, optimization and physiologically based pharmacokinetic modeling

Diacerein (DCN), a BCS II compound, suffers from poor aqueous solubility and limited bioavailability. Solid dispersion systems (SD) of DCN were prepared by solvent evaporation, using hydrophilic polymers. In-vitro dissolution studies were performed and dissolution parameters were evaluated. I-Optimal factorial design was employed to study the effect of formulation variables (drug:polymer ratio and polymer type) on the measured responses including; drug content (DC) (%), dissolution efficiency at 15 min (DE _{(15 min)}%) and 60 min (DE _{(60 min)}%) and mean dissolution time (MDT) (min). The optimized SD was selected, prepared and evaluated, allowing 10.83 and 3.42 fold increase in DE _{(15 min)}%, DE _{(60 min)}%, respectively and 6.07 decrease in MDT, compared to plain drug. DSC, XRD analysis and SEM micrographs confirmed complete amorphization of DCN within the optimized SD. Physiologically based pharmacokinetic (PBPK) modeling was employed to predict PK parameters of DCN in middle aged healthy adults and geriatrics. Simcyp^® software established in-vivo plasma concentration time curves of the optimized SD, compared to plain DCN. Relative bioavailability of the optimized SD compared to plain drug was 229.52% and 262.02% in healthy adults and geriatrics, respectively. Our study reports the utility of PBPK modeling for formulation development of BCS II APIs, via predicting their oral bio-performance.

Suitability assessment of dumpsite soil biocover to reduce methane emission from landfills under interactive influence of nutrients

Biocovers are known for their role as key facilitator to reduce landfill methane (CH₄) emission on improving microbial methane bio-oxidation. Methanotrophs existing in the aerobic zone of dumped wastes are the only known biological sinks for CH₄ being emitted from the lower anaerobic section of landfill sites and even from the atmosphere. However, their efficacy remains under the influence of landfill environment and biocover characteristics. Therefore, the present study was executed to explore the suitability and efficacy of dumpsite soil as biocover to achieve enhanced methane bio-oxidation under the interactive influence of nutrients, carbon source, and environmental factors using statistical-mathematical models. The Placket-Burman design (PBD) was employed to identify the significant factors out of 07 tested factors having considerable impact on CH₄ bio-oxidation. The normal plot and Student's t test of PBD indicated that ammonical nitrogen (NH₄⁺-N), nitrate nitrogen (NO₃^--N), methane (CH₄), and copper (Cu) concentration were found significant. A three-level Box-Behnken design (BBD) was further applied to optimize the significant factors identified from PBD. The BBD results revealed that interactive interaction of CH₄ with NH₄⁺-N and NO₃^--N affected the CH₄ bio-oxidation significantly. The sequential statistical approach predicted that maximum CH₄ bio-oxidation of 27.32 μg CH₄ h^-1 could be achieved with CH₄ (35%), NO₃^--N (250 μg g^-1), NH₄+-N (25 μg g^-1), and Cu (50 mg g^-1) concentration. Conclusively, waste dumpsite soil could be a good alternative over conventional soil cover to improve CH₄ bio-oxidation and lessen the emission of greenhouse gas from waste sector.

Bilosomes as Promising Nanovesicular Carriers for Improved Transdermal Delivery: Construction, in vitro Optimization, ex vivo Permeation and in vivo Evaluation

Purpose

The goal of this research was to enhance the transdermal delivery of lornoxicam (LX), using nanovesicular carriers composed of the bile salt sodium deoxycholate (SDC), soybean phosphatidyl choline (SPC) and a permeation enhancer limonene.

Methods

Thin-film hydration was the technique employed for the fabrication using a Box–Behnken design with three central points. The investigated factors were SPC molar concentration, SDC amount in mg and limonene percentage (%). The studied responses were percent entrapment efficiency (%EE), particle size (PS), polydispersity index (PDI), zeta potential (ZP), and in vitro drug release (after 2, 10 h). In order to obtain the optimum formula, numerical optimization by Design-Expert® software was used. Electing the optimized bilosomal formula was based on boosting %EE, ZP (as absolute value) and in vitro drug release, taking in consideration diminishing PS and PDI. Further assessment of the selected formula was achieved by transmission electron microscopy (TEM), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), stability testing, ex vivo skin permeation and deposition. The in vivo pharmacodynamics activities of the optimized formula were examined on male rats and mice and compared to that of the oral market product.

Results

The optimized bilosomal formula demonstrated to be nonirritant, with noticeably enhanced anti-inflammatory and antinociceptive activities. Superior in vivo permeation was proved by confocal laser scanning microscopy (CLSM).

Conclusion

The outcomes demonstrated that bilosomes could improve transdermal delivery of lornoxicam.

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Hexosomes as Efficient Platforms for Possible Fluoxetine Hydrochloride Repurposing with Improved Cytotoxicity against HepG2 Cells

The aim of this study was to investigate the feasibility of hexosomes (HEXs) as competent platforms for fluoxetine hydrochloride (FH) repurposing against HepG2 hepatocellular carcinoma. Different FH-loaded HEX formulations were prepared and optimized by the hot emulsification method. The HEX features such as particle size, ζ potential, and drug entrapment efficiency (EE%) can be tailored by tuning HEX components and fabrication conditions. The composition of the optimized FH hexosome (OFH-HEX) was composed of 3.1, 1.4, 0.5, 0.2, and 94.8% for glyceryl monooleate, oleic acid, pluronic F127, FH, and deionized water, respectively. The anionic OFH-HEX with a particle size of 145.5 ± 2.5 nm and drug EE% of 45.4 ± 1.2% was able to prolong the in vitro FH release, where only 19.5 ± 2.3% released in phosphate-buffered saline (PBS) pH 7.4 after 24 h. Contrarily, HEX rapidly released FH in acetate buffer pH 5.5 and achieved a 90.5 ± 4.7% release after 24 h. The obtained HEX showed an improved cellular internalization in a time-dependent manner and enhanced the cytotoxicity (2-fold higher than FH solution). The current study suggests the potential of FH-HEX as a possible anticancer agent against hepatocellular carcinoma.

Development of a Solid Formulation Containing a Microemulsion of a Novel Artemisia Extract with Nematocidal Activity for Oral Administration

Background: Intestinal nematode infections are usually treated with benzimidazole drugs, but the emergence of resistance to these drugs has led to an increasing demand of new anthelmintic strategies. A new microemulsion formulation (ME) consisting of an Artemisia absinthium extract with proven nematocidal efficacy was previously developed. The aim of our study is to implement a D-optimal mixture design methodology to increase the amount of a silica material (loaded with this ME) in a tablet formulation, considering its tensile strength and disintegration time. Methods: 16 experiments or combinations of the 6 tablet components (loaded silica, microcrystalline cellulose, polyvinylpyrrolidone, croscarmellose, Syloid^® 244 FP and magnesium stearate) were assessed. Tensile strength and disintegration time models were developed, and an optimization process was carried out. Results: Tensile strength was improved by increasing the polyvinylpyrrolidone content, while croscarmellose decreased the disintegration time. The optimized powder mixture contains 49.7% w/w of the loaded silica material. A compression force of 12 kN was applied to the powder mixture to form tablets with a tensile strength of 2.0 MPa and a disintegration time of 3.8 min. Conclusions: Our results show that D-optimal mixture designs provide a promising approach to formulate liquid-loaded silica materials.

Comprehensive Study of Intermediate and Critical Quality Attributes for Process Control of High-Shear Wet Granulation Using Multivariate Analysis and The Quality by Design Approach

A robust manufacturing process and the relationship between intermediate quality attributes (IQAs), critical quality attributes (CQAs), and critical process parameters (CPPs) for high-shear wet granulation was determined in this study. Based on quality by the design (QbD) approach, IQAs, CQAs, and CPPs of a telmisartan tablet prepared by high-shear wet granulation were determined and then analyzed with multivariate analysis (MVA) to evaluate mutual interactions between IQAs, CQAs, and CPPs. The effects of the CPPs on the IQAs and CQAs were quantitatively predicted with empirical models of best fit. The models were used to define operating space, and an evaluation of the risk of uncertainty in model prediction was performed using Monte Carlo simulation. MVA showed that granule size and granule hardness were significantly related to % dissolution. In addition, granule FE (Flow Energy) and Carr's index had effects on tablet tensile strength. Using the manufacture of a clinical batch and robustness testing, a scale-up from lab to pilot scale was performed using geometric similarity, agitator torque profile, and agitator tip speed. The absolute biases and relative bias percentages of the IQAs and CQAs generated by the lab and pilot scale process exhibited small differences. Therefore, the results suggest that a risk reduction in the manufacturing process can be obtained with integrated process parameters as a result of the QbD approach, and the relationship between IQAs, CQAs, and CPPs can be used to predict CQAs for a control strategy and SUPAC (Scale-Up and Post-Approval Guidance).

Effects of granulation process variables on the physical properties of dosage forms by combination of experimental design and principal component analysis

The current study was to understand how process variables of high shear wet granulations affect physical properties of granules and tablets. The knowledge gained was intended to be used for Quality-by-Design based process design and optimization. The variables were selected based on the risk assessment as impeller speed, liquid addition rate, and wet massing time. Formulation compositions were kept constant to minimize their influence on granules properties. Multiple linear regression models were built providing understanding of the impact of each variable on granule hardness, Carr's index, tablet tensile strength, surface mean diameter of granules, and compression behavior. The experimental results showed that the impact of impeller speed was more dominant compared to wet massing time and water addition rate. The results also revealed that quality of granules and tablets could be optimized by adjusting specific process variables (impeller speed 1193 rpm, water spray rate 3.7 ml/min, and wet massing time 2.84 min). Overall desirability was 0.84 suggesting that the response values were closer to the target one. The SEM image of granules showed that spherical and smooth granules produced at higher impeller speed, whereas rough and irregular shape granules at lower speed. Moreover, multivariate data analysis demonstrated that impeller speed and massing time had strong correlation with the granule and tablet properties. In overall, the combined experimental design and principal component analysis approach allowed to better understand the correlation between process variables and granules and tablet attributes.

Solutol HS15 based binary mixed micelles with penetration enhancers for augmented corneal delivery of sertaconazole nitrate: optimization, in vitro, ex vivo and in vivo characterization

Keratomycosis is a serious corneal disease that can cause a permanent visual disability if not treated effectively. Sertaconazole nitrate (STZ), a novel broad spectrum antifungal drug, was suggested as a promising treatment. However, its utility in the ocular route is restricted by its poor solubility, along with other problems facing the ocular delivery like short residence time, and the existing corneal barrier. Therefore, the objective of this study was to formulate STZ loaded binary mixed micelles (STZ-MMs) enriched with different penetration enhancers using thin-film hydration method, based on a 3¹.2² mixed factorial design. Different formulation variables were examined, namely, type of auxiliary surfactant, type of penetration enhancer, and total surfactants: drug ratio, and their effects on the solubility of STZ in MMs (S_M), particle size (PS), polydispersity index (PDI), and zeta potential (ZP) were evaluated. STZ-MMs enhanced STZ aqueous solubility up to 338.82-fold compared to free STZ. Two optimized formulations (MM-8 and MM-11) based on the desirability factor (0.891 and 0.866) were selected by Design expert^® software for further investigations. The optimized formulations were imaged by TEM which revealed nanosized spherical micelles. Moreover, they were examined for corneal mucoadhesion, stability upon dilution, storage effect, and ex vivo corneal permeation studies. Finally, both in vivo corneal uptake and in vivo corneal tolerance were investigated. MM-8 showed superiority in the ex vivo and in vivo permeation studies when compared to the STZ-suspension. The obtained results suggest that the aforementioned STZ loaded mixed micellar system could be an effective candidate for Keratomycosis-targeted therapy.

Zero-order release and bioavailability enhancement of poorly water soluble Vinpocetine from self-nanoemulsifying osmotic pump tablet

Solid self-nanoemulsifying (S-SNEDDS) asymmetrically coated osmotic tablets of the poorly water-soluble drug Vinpocetine (VNP) were designed. The aim was to control the release of VNP by the osmotic technology taking advantage of the solubility and bioavailability-enhancing capacity of S-SNEDDS. Liquid SNEDDS loaded with 2.5 mg VNP composed of Maisine™ 35-1, Transcutol® HP, and Cremophor® EL was adsorbed on the solid carrier Aeroperl®. S-SNEDDS was mixed with the osmotic tablet excipients (sodium chloride, Avicel®, HPMC-K4M, PVP-K30, and Lubripharm®), then directly compressed to form the core tablet. The tablets were dip coated and mechanically drilled. A 32*21 full factorial design was adopted. The independent variables were: type of coating material (X1), concentration of coating solution (X2), and number of drills (X3). The dependent variables included % release at 2 h (Y1), at 4 h (Y2), and at 8 h (Y3). The in vivo performance of the optimum formula was assessed in rabbits. Zero-order VNP release was obtained by the single drilled 1.5% Opadry® CA coated osmotic tablets and twofold increase in VNP bioavailability was achieved. The combination of SNEDDS and osmotic pump tablet system was successful in enhancing the solubility and absorption of VNP as well as controlling its release.

Corneal targeted Sertaconazole nitrate loaded cubosomes: Preparation, statistical optimization, in vitro characterization, ex vivo permeation and in vivo studies

Sertaconazole nitrate (STZ) is a poorly soluble antifungal drug commonly used for treating fungal skin infections. Introducing it as a new treatment option for the management of fungal keratitis, requires the development of a delivery system capable of targeting the infected cornea with an adequate STZ concentration. Hence, Sertaconazole nitrate loaded cubosomes (STZ-CUBs) were prepared, characterized and optimized based on a 3³ central composite face-centred design. Optimized formulation (CUB-opt) showed maximum desirability (0.905), with solubilization efficiency (SE%) of 94.50 ± 0.51%, particle size (PS) of 216.55 ± 2.33 nm, polydispersity index (PDI) of 0.229 ± 0.11 and zeta potential (ZP) of 34.00 ± 6.93 mV. Under the transmission electron microscope, it showed discrete cubic shaped structures. Moreover, it exhibited a promising mucoadhesive behavior, terminal sterilization stability, and storage stability. Ex vivo corneal permeation study revealed its ability to enhance the steady state flux (J_ss) and the permeability coefficient (K_P) of STZ, compared to STZ-suspension. Finally, CUB-opt formulation was found to be safe on the corneal tissues in the in vivo corneal tolerance study, and demonstrated a superior corneal penetration power in the in vivo corneal uptake study.

Design and optimization of gastric floating sustained-release mini-tablets of alfuzosin hydrochloride based on a factorial design: in vitro/in vivo evaluation

The purpose of this research was to develop multiple-unit gastric floating mini-tablets and to evaluate the possibility of using these mini-tablets as a delivery system to improve the drug absorption for drugs with a narrow absorption window. Mini-tablets were prepared using hydroxypropyl methylcellulose (HPMC K100M) and carbopol 971P as release retarding agents and sodium bicarbonate (NaHCO₃) as gas-forming agent. The properties of the prepared mini-tablets in terms of floating characteristic parameters and in vitro release were evaluated. Furthermore, in vivo gastric retention study in rats and in vivo pharmacokinetic study in rabbits of the optimized formulation were performed. The optimized mini-tablets containing 45% HPMC K100M, 15% stearyl alcohol, 13% carbopol 971P, and 12% NaHCO₃ were found to float immediately within 1 min and duration more than 9 h. The in vivo gastric retention study results indicated that the mini-tablets could retain in the stomach for more than 6.67 h. Furthermore, the AUC_0-t of the floating mini-tablets (6849.83 ± 753.80 h ng·mL^-1) was significantly higher than that of marketed sustained-release tablets XATRAL®XL (4970.16 ± 924.60 h ng·mL^-1). All these results illustrated that the gastric floating mini-tablets might be a promising drug delivery system for drugs with a narrow absorption window.

Enhanced transdermal delivery of ondansetron using nanovesicular systems: Fabrication, characterization, optimization and ex-vivo permeation study-Box-Cox transformation practical example

This study aimed to formulate suitable nanovesicles (NVs) for transdermal delivery of Ondansetron. It also illustrated a practical example for the importance of Box-Cox transformation. A 2³ full factorial design was used to enable testing transfersomes, ethosomes, and transethosomes of Ondansetron simultaneously. The independent variables (IVs) studied were sodium taurocholate amount, ethanol volume in hydration medium and sonication time. The studied dependent variables (DVs) were: particle size (PS), zeta potential (ZP) and entrapment efficiency (EE). Polynomial equations were used to study the influence of IVs on each DV. Numerical multiple response optimization was applied to select an optimized formula (OF) with the goals of minimizing PS and maximizing ZP absolute value and EE. Box-Cox transformation was adopted to enable modeling PS raised to the power of 1.2 with an excellent prediction R² of 1.000. ZP and EE were adequately represented directly with prediction R² of 0.9549 and 0.9892 respectively. Response surface plots helped in explaining the influence of IVs on each DV. Two-sided 95% prediction interval test and percent deviation of actual values from predicted ones proved the validity of the elucidated models. The OF was a transfersomal formula with desirability of 0.866 and showed promising results in ex-vivo permeation study.

Transdermal agomelatine microemulsion gel: pyramidal screening, statistical optimization and in vivo bioavailability

Agomelatine is a new antidepressant having very low oral drug bioavailability less than 5% due to being liable to extensive hepatic 1st pass effect. This study aimed to deliver agomelatine by transdermal route through formulation and optimization of microemulsion gel. Pyramidal screening was performed to select the most suitable ingredients combinations and then, the design expert software was utilized to optimize the microemulsion formulations. The independent variables of the employed mixture design were the percentages of capryol 90 as an oily phase (X1), Cremophor RH40 and Transcutol HP in a ratio of (1:2) as surfactant/cosurfactant mixture 'Smix' (X2) and water (X3). The dependent variables were globule size, optical clarity, cumulative amount permeated after 1 and 24 h, respectively (Q1 and Q24) and enhancement ratio (ER). The optimized formula was composed of 5% oil, 45% Smix and 50% water. The optimized microemulsion formula was converted into carbopol-based gel to improve its retention on the skin. It enhanced the drug permeation through rat skin with an enhancement ratio of 37.30 when compared to the drug hydrogel. The optimum ME gel formula was found to have significantly higher Cmax, AUC 0-24 h and AUC0-∞ than that of the reference agomelatine hydrogel and oral solution. This could reveal the prosperity of the optimized microemulsion gel formula to augment the transdermal bioavailability of agomelatine.

Development, Internal and External Validation of Naproxen Sodium Sustained Release Formulation: an Level A In Vitro-In Vivo Correlation

Objectives

The aim of the present study was to develop and validate an in vitro-in vivo correlation (IVIVC) for naproxen sodium-sustained release tablets and to compare their plasma concentrations over time with the immediate-release tablets.

Materials and Methods

In vitro release rate data were obtained for each tablet by using the USP Apparatus II, paddle stirrer at 50 rpm in pH 7.4 phosphate buffer. A four-way crossover study was conducted in 6 healthy subjects by administering naproxen sodium sustained release 375 mg and 500 mg of immediate release tablets. Series of blood samples were collected over 24 hours and estimated by using the validated liquid chromatography tandem-mass spectrometry method.

Results

The similarity factor was calculated and it was found that values between, 50 and 100 indicates similarity of the profiles. Assessment of predicted and observed bioavailability was performed and prediction errors (PE) % calculated, as per the Food Drug Administration guidelines, the average absolute PE% of C_max and AUC of individual formulation was found below 15% for establishment of IVIVC, based on internal prediction strongly suggesting that the naproxen sodium IVIVC models are valid. During external validation the predicted curve for the naproxen sodium sustained-release tablets was found to be identical to immediate release tablets and considered as valid.

Conclusion

IVIVC can serve as a surrogate for in vivo bioavailability study and supports biowaivers, supports and validates the dissolution methods and specification settings and assists in quality control during scale-up and post-approval changes. It may be used to predict the variation in site change, process changes and to predict the absorption performance of naproxen sodium products with different release rates.

Design of Isoniazid Smart Nanogel by Gamma Radiation-Induced Template Polymerization for Biomedical Application

PURPOSE

Preparation of Isoniazid (INH) loaded nanogel particles using gamma radiation as safe, simple, cheap and reproducible technique for promoting mycobacterial killing in a lower-dose system aiming in developing of drug resistance.

METHODS

Polymeric pH-sensitive nanogels were prepared by gamma radiation-induced polymerization of Acrylic acid (AAc) or Itaconic acid (IA), in aqueous solution of polyvinylpyrrolidone (PVP), as template polymer. The prepared nanogels were utilized for encapsulation of INH. 3¹X2² factorial design was employed for optimization and exploring the effect of radiation dose (X₁) (30-50kGy), ratio of PVP: acid (X₂) (50:50-30:70) and type of acid (X₃) on the prepared nanogel characterization RESULTS: The optimized levels of X₁, X₂ and X₃ were (50 KGy, 30:70 and Itaconic acid, respectively), with a desirability of 0.959. In-vitro INH release rate from the prepared nanogels decreased with increasing gamma radiation doses, with the predominance of the diffusion mechanism for drug release pattern. In addition, it was perceived that the minimum inhibitory concentration (MIC) of INH loaded PVP/PIA nanogels on Mycobacteria Tuberculosis was 8 folds lower than that of INH solution.

CONCLUSION

The prospective of PVP-K90/PIA was recommended as a smart candidate for delivery of INH with promising achievements against tuberculosis than free drug. Graphical abstract Mechanism of formation and loading of Isoniazid PVP/PIA nanogel.

Tri-block co-polymer nanocarriers for enhancement of oral delivery of felodipine: preparation, in vitro characterization and ex vivo permeation

This study aimed to prepare, optimize and characterize novel felodipine-loaded polymeric nanomicelles, using a pluronic mixture of F127 and P123. Thin-film hydration method was adopted for the preparation of different polymeric nanomicelles (T1-T12) according to a 4¹.3¹ full factorial design. Factors studied were: Pluronic®:drug ratio (P:D ratio) (10, 20, 30 and 40 w/w) and percent of hydrophilic polymer (F127%) (33.33%, 50% and 66.67% w/w). Optimization criteria were to maximize transmittance percent (T%) and entrapment efficiency percent (EE%) and to minimize particle size (PS) and polydispersity index (PDI). The optimized formulation was further characterized by DSC, FTIR and ¹H NMR studies. It was also subjected to stability testing and ex vivo permeation using rabbit intestines. Spherical nanomicelles of particle size ranging from 26.18 to 87.54 nm were successfully obtained. The optimized formulation was found to be the already prepared formulation T12 (P:D ratio of 40 and 66.67% F127) with suitable T% and EE% of 95.12% and 91.75%, respectively. DSC, FTIR and ¹H NMR studies revealed felodipine (FLD) incorporation within T12 nanomicelles. T12 enhanced the ex vivo intestinal permeation of FLD when compared to a drug suspension and showed good stability. Therefore, pluronic nanomicelles could be promising for improved oral delivery of FLD.

Continuous melt granulation to develop high drug loaded sustained release tablet of Metformin HCl

The present work explores the application of melt granulation technology to develop a high drug loaded sustained release matrix tablet of Metformin HCl using hydroxypropylcellulose (HPC) as a hydrophilic binder and stearic acid as an extrusion aid for producing cohesive granules. This novel approach allowed the use of a minimum number of excipients to reduce the tablet size, and to enhance compressibility of the drug. This also offered a cost effective method owing to the elimination of a ‘drying step’ prevalent in wet granulation method. Moreover, this research also focuses on resolving the processability issues associated with the use of HPC Nisso-H at high drug loading. The thermal lubricants were screened for this purpose and evaluated for their impact on extrudability, granule and tablet characteristics. Stearic acid was selected as the thermal lubricant, which not only contributed to the inhibition of burst release, but also improved the flow property of the granules.

The developed matrix tablet (75% drug loading) resulted in 670 mg of weight for 500 mg dose strength and showed sustained drug release over 10 h. When compared, with conventional granulation techniques, it was observed that, under identical compression force, the tablet prepared by MG exhibited superior compactibility along with tablet hardness and optimal drug release profile. FTIR suggested nonexistence of chemical interaction between the drug and the other excipients while XRD and DSC analysis revealed the crystalline state of the drug. Furthermore, the results obtained from Raman spectroscopy proved the uniform distribution of the Metformin HCl and polymer in the final dosage form. This technology leads to the manufacture of sustained release matrix formulation with reduced tablet size of a high dose, highly water soluble drug otherwise difficult to process using standard batch-granulation.

Design and evaluation of an innovative floating and bioadhesive multiparticulate drug delivery system based on hollow structure

In this study a gastric-retentive delivery system was prepared by a novel method which is reported here for the first time. An innovative floating and bioadhesive drug delivery system with a hollow structure was designed and prepared. The floating and bioadhesive drug delivery system was composed of a hollow spherical shell, a waterproof layer (Stearic acid), a drug layer (Ofloxacin), a release retarding film (the novel blended coating materials) and a bioadhesive layer (Carbomer 934P) prepared by using a liquid multi-layering process. A novel blended coating material was designed and investigated to solve the problem of the initial burst release of the formulation and the release mechanism of the novel material was analyzed in this study. The optimized formulation provided the sustained release characteristic and was able to float for 24h. The SEM cross-section images showed that the particulates were hollow with a spherical shell. X-ray images and pharmacokinetic studies (Frel = 124.1 ± 28.9%) in vivo showed that the gastric-retentive delivery system can be retained in the stomach for more than 6h. The floating and bioadhesive particulate drug delivery system based on a hollow structure with a dual function presented here is a viable alternative to other for gastroretentive drug delivery system.

Hypolipidemic potential of perillaldehyde-loaded self-nanoemulsifying delivery system in high-fat diet induced hyperlipidemic mice: Formulation, in vitro and in vivo evaluation

This study reports the hypolipidemic effects of perillaldehyde-loaded self-nanoemulsifying delivery system (PAH-SNEDS) developed with D-optimal experimental design based on a three component system: 40% w/w drug-oil phase, X1 (a mixture of perillaldehyde-isopropyl myristate/medium chain triglyceride, 1:1, w/w); 48% surfactant, X2 (Kolliphor EL); and 12% co-surfactant, X3 (PEG 200). The design space was navigated using a linear model to produce spherical and homogenous droplets which were observed under TEM, with mean size, polydispersity index (PDI) and zeta potential of 32.8 ± 0.1 nm, 0.270 ± 0.029 and -10.14 ± 0.66 mV, respectively. PAH-SNEDS demonstrated significant increase in dissolution in vitro compared to the free PAH, and further yielded an oral relative bioavailability of about 206.18% in vivo which suggested a promising formulation design for potential liquid bioactive compounds. Oral administration of PAH-SNEDS (240 mg/kg per body weight) in high-fat induced hyperlipidemia in mice, also significantly decreased serum total cholesterol (TC), triglyceride (TG) and low-density lipoprotein cholesterol (LDL-C) while increasing high-density lipoprotein cholesterol (HDL-C) level. The improved bioavailability and functional application of PAH via SNEDDS suggested a suitable approach to promote hypolipidemic effect of the drug. Perillaldehyde, therefore, promises to be a useful bioactive compound to prevent high-fat diet induced hyperlipidemia.

Utilization of ionotropic gelation technique for bioavailability enhancement of cinnarizine: in-vitro optimization and in-vivo performance in human

Gastro retentive drug delivery system techniques were adopted to deliver drugs having narrow absorption window from a particular site in the GIT. Therefore, gastro retentive dosage forms were retained in the stomach, thus improving absorption and bioavailability would be improved consequently. In this study, cinnarizine (CNZ) was employed as the model drug. CNZ is a poorly soluble basic drug, suffering from low and erratic bioavailability. This is attributed to its pH-dependant solubility (highly soluble at pH < 4). CNZ is characterized by short half-life (3-6 h). Accordingly, floating CNZ emulsion gel calcium pectinate beads were developed. A mixture design was employed to study the effect of the percent of LM pectin (A), the percent of GMO (B) and the percent of Labrafac Lipophile (C) simultaneously on the percent of drug released and loaded. The optimized floating CNZ emulsion gel calcium pectinate beads and Stugeron® (the marketed reference product) were compared through a pharmacokinetic study carried on healthy human volunteers. Fortunately, simple floating CNZ emulsion gel calcium pectinate beads were prepared with zero-order release profile for 12 h. A promising in-vivo CNZ controlled release dosage form with higher bioavailability, when compared to once daily administration of Stugeron® tablets was achieved.

Combined application of mixture experimental design and artificial neural networks in the solid dispersion development

This study for the first time demonstrates combined application of mixture experimental design and artificial neural networks (ANNs) in the solid dispersions (SDs) development. Ternary carbamazepine-Soluplus®-poloxamer 188 SDs were prepared by solvent casting method to improve carbamazepine dissolution rate. The influence of the composition of prepared SDs on carbamazepine dissolution rate was evaluated using d-optimal mixture experimental design and multilayer perceptron ANNs. Physicochemical characterization proved the presence of the most stable carbamazepine polymorph III within the SD matrix. Ternary carbamazepine-Soluplus®-poloxamer 188 SDs significantly improved carbamazepine dissolution rate compared to pure drug. Models developed by ANNs and mixture experimental design well described the relationship between proportions of SD components and percentage of carbamazepine released after 10 (Q10) and 20 (Q20) min, wherein ANN model exhibit better predictability on test data set. Proportions of carbamazepine and poloxamer 188 exhibited the highest influence on carbamazepine release rate. The highest carbamazepine release rate was observed for SDs with the lowest proportions of carbamazepine and the highest proportions of poloxamer 188. ANNs and mixture experimental design can be used as powerful data modeling tools in the systematic development of SDs. Taking into account advantages and disadvantages of both techniques, their combined application should be encouraged.

Formulation, characterization, and evaluation of ligand-conjugated biodegradable quercetin nanoparticles for active targeting

The aim of this study was to design a targeted drug delivery system carrying a natural anticancer drug Quercetin (Qu), specifically for skin cancer. A central composite design was applied separately for each ligand, and the quadratic model was used for the process. The surface morphology was confirmed by transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR), and in vitro release studies were also performed. The MTT assay was performed against two different cell lines, to measure their anticancer potentials and their targeting ability. The study thus reveals that MA-Qu-PLGA and FA-Qu-PLGA nanoparticles (NPs) can be used as effective drug delivery systems for skin cancer treatment encompassing natural drugs.

Disintegration mediated controlled release supersaturating solid dispersion formulation of an insoluble drug: design, development, optimization, and in vitro evaluation

The objective of this study was to develop a solid dispersion based controlled release system for drug substances that are poorly soluble in water. A wax-based disintegration mediated controlled release system was designed based on the fact that an amorphous drug can crystallize out from hydrophilic matrices. For this study, cilostazol (CIL) was selected as the model drug, as it exhibits poor aqueous solubility. An amorphous solid dispersion was prepared to assist the drug to attain a supersaturated state. Povidone was used as carrier for solid dispersion (spray drying technique), hydrogenated vegetable oil (HVO) as wax matrix former, and sodium carboxymethyl cellulose (NaCMC) as a disintegrant. The extreme vertices mixture design (EVMD) was applied to optimize the designed and developed composition. The optimized formulation provided a dissolution pattern which was equivalent to the predicted curve, ascertaining that the optimal formulation could be accomplished with EVMD. The release profile of CIL was described by the Higuchi's model better than zero-order, first-order, and Hixson-Crowell's model, which indicated that the supersaturation state of CIL dominated to allow drug release by diffusion rather than disintegration regulated release as is generally observed by Hixson-Crowell's model. The optimized composition was evaluated for disintegration, dissolution, XRD, and stability studies. It was found that the amorphous state as well as the dissolution profile of CIL was maintained under the accelerated conditions of 40°C/75% RH for 6 months.

Improved percutaneous delivery of azelaic acid employing microemulsion as nanocarrier: formulation optimization, in vitro and in vivo evaluation

Topical administration of an optimal microemulsion could effectively enhance the amount of azelaic acid in skin without causing skin irritation.

Development and validation of an in vitro–in vivo correlation (IVIVC) model for propranolol hydrochloride extended-release matrix formulations

The objective of this study was to develop an in vitro–in vivo correlation (IVIVC) model for hydrophilic matrix extended-release (ER) propranolol dosage formulations. The in vitro release characteristics of the drug were determined using USP apparatus I at 100 rpm, in a medium of varying pH (from pH 1.2 to pH 6.8). In vivo plasma concentrations and pharmacokinetic parameters in male beagle dogs were obtained after administering oral, ER formulations and immediate-release (IR) commercial products. The similarity factor f₂ was used to compare the dissolution data. The IVIVC model was developed using pooled fraction dissolved and fraction absorbed of propranolol ER formulations, ER-F and ER-S, with different release rates. An additional formulation ER-V, with a different release rate of propranolol, was prepared for evaluating the external predictability. The results showed that the percentage prediction error (%PE) values of C_max and AUC_0–∞ were 0.86% and 5.95%, respectively, for the external validation study. The observed low prediction errors for C_max and AUC_0–∞ demonstrated that the propranolol IVIVC model was valid.