Optimization of gliclazide loaded alginate-gelatin beads employing central composite design

Application of Response Surface Methodology Using Face-centered Central Composite Design for Studying Long-Term Stability of Gliclazide-Loaded Multiparticulate Systems

The appropriate design of experiments (DoE) could support post-approval lean-stability approaches. A three-factor three-level face-centered design was constructed to evaluate the long-term stability of gliclazide (GLZ) alginate-gelatin beads. The formulation variables were GLZ%(X1), alginate:gelatin ratio(X2), and glutaraldehyde%(X3). The studied responses included GLZ release at predefined intervals in 0.1 N HCl (2 h) followed by phosphate buffer (pH 7.4). Model-dependent and independent approaches were utilized for comparison. DoE-model validation and reduction were implemented. All the studied formulations showed non-significant changes in the particle size (p > 0.05) and most of them showed similar release profiles before and after storage. The directions of the relationships between the factors' main effects and the responses (Y1:Q0.5h, Y2:Q2h, and Y3:Q4h) remained unchanged after storage. The optimal factor settings based on the proposed optimization criteria were defined. The optimized formulations (OP-1 and OP-2) showed non-significant changes in the particle size after storage. The release profiles and kinetics of OP-1 and OP-2 remained unchanged after storage. No chemical change was indicated (FT-IR). DSC-thermograms of OP-1 indicated GLZ conversion to a more stable polymorph after storage. While OP-2 showed a change in GLZ crystallinity. The stored and fresh beads' surfaces after GLZ release were almost similar. DoE could be utilized to evaluate, optimize, and predict the effects of different formulation variables on the long-term stability of GLZ alginate-gelatin beads.

Quality by design (QbD) approach to develop fast-dissolving tablets using melt-dispersion paired with surface-adsorption method: formulation and pharmacokinetics of flurbiprofen melt-dispersion granules

Developing amorphous solid dispersions with good flow properties is always challenging for formulation scientists to convert into tablets. Hence, the present study investigates the impact of the combination of melt-dispersion and surface-adsorption methods to prepare melt-dispersion granules with enhanced dissolution rate and flow properties. This study covers the formulation and pharmacokinetic study of fast-dissolving flurbiprofen tablets using PEG 6000 (hydrophilic carrier) and lactose (adsorbent). Response surface methodology (RSM) using the central composite design (CCD) was used to optimize independent variables like carrier concentrations and adsorbent concentrations, and their interactions with the dependent variables (responses), including solubility, angle of repose, Carr's index, and cumulative % drug release, were investigated. The optimized formulation was selected based on the numerical optimization method and further investigated for FTIR spectroscopy, differential scanning calorimetry, and X-ray diffractometry. Then, the optimized formulation was compressed into tablets and evaluated for both in vitro dissolution and in vivo pharmacokinetics parameters. In vitro dissolution studies revealed that the prepared fast-dissolving tablets released the drug entirely within 15 min (Q15 of F4 tablets: 99.34 ± 1.24%), whereas conventional tablets took around 60 min for complete dissolution. Pharmacokinetic studies in rats revealed that fast-dissolving tablets showed 1.38-fold higher peak-plasma concentration (Cmax) and 1.39-fold higher bioavailability than conventional tablets. Overall, this study revealed the successful fabrication of fast-dissolving tablets via melt-dispersion paired with the surface-adsorption method to enhance the flow properties and the dissolution rate.

Optimization of oil yield of Pelargonium graveolens L'Hér using Box-Behnken design in relation to its antimicrobial activity and in silico study

Pelargonium graveolens L'Hér is an important species of genus Pelargonium with an economic value. The unique rose scent of its oil is used in perfume and cosmetic industry. The oil is characterized by the presence of citronellol, geraniol and rose oxide. Fresh aerial parts of P. graveolens at GC-MS analysis of four seasons revealed that autumn constituted the highest yield of the oil. For the first time, optimization of the yield of extracted oil of P. graveolens was performed employing 3-level Box-Behnken design using 3-factors. The GC-MS analysis of the essential oil was performed for the 17-runs. The optimized extraction of the oil was performed employing numerical optimization and studied for antimicrobial, Minimum Inhibitory Concentration (MIC) and biofilm inhibitory activities. The 3 factors followed rank (plant material amount > water volume > NaCl percent in water), in their magnitude of effect on increasing yield of the oil. Increasing the plant material amount increased the yield of the oil by 6-folds compared to NaCl percent in water. The optimized yield of oil (4 ml) was obtained from extraction criteria (150 g of plant, 750 ml of water and 3.585% (26.85 g) of NaCl). Computational docking was performed to overcome the multi-drug resistant Gram-negative bacilli targeting undecaprenyl pyrophosphate synthase (UPPS). The optimized oil exhibited a promising inhibitory activity against Gram-negative bacteria (K. pneumonia and P. aeruginosa) with significant antibiofilm action (P < 0.05). Moreover, it exerted a synergistic effect when combined with various antibiotics (Cefoxitin, Cloxacillin, Oxacillin and Vancomycin) against MRSA clinical strains.

Formulation and evaluation of alginate-gelatin hydrogel scaffolds loaded with zinc-doped hydroxyapatite and 5-fluorouracil

Alginate and gelatin are natural macromolecules used to formulate biocompatible drug delivery systems. Hydroxyapatite (HA) is an osteophilic ceramic used to prepare bone scaffolds. The current study aimed at preparing and characterizing HA, zinc-doped HA, and 5-fluorouracil(5-FU)-loaded alginate-gelatin-based hydrogel scaffolds using different crosslinking solutions. 5-FU incorporation efficiency, in-vitro drug release, antitumor bioassays, FTIR, X-ray-diffraction (XRD), High-Resolution Transmission, and Scanning-Electron Microscope (HR-TEM and SEM) studies were conducted. XRD showed the incorporation of Zn²⁺ into HA structure with a deformity in HA crystal lattice and inhibited crystal growth. FTIR-spectra represented the characteristic bands corresponding to HA structure. HR-TEM showed a decreased HA crystal size and rod-like crystallites that increased with increasing zinc content. Zn²⁺ content and 5-FU-loading caused significant effects on the scaffolds' thickness (p-value = 0.021 and 0.035, respectively). Burst 5-FU release within 10-15 min followed by 100 % release within 4 h was observed. Zinc content showed a significant positive effect on the cytotoxicity% of the blank and drug-loaded scaffolds. XRD and FTIR studies revealed that 5-FU was completely incorporated into the hydrogel with no chemical interaction. SEM-imaging showed interconnected pores and needle-shaped drug particles. The prepared formulations showed promising physico-chemical properties for targeted delivery of 5-FU in the form of biocompatible bone scaffolds.

Chitosan Nanoparticles Loaded Poloxamer 407 Gel for Transungual Delivery of Terbinafine HCl

The current study aimed to develop chitosan nanoparticles (CSNP) loaded poloxamer 407 (P407) gel formulation for transungual delivery of terbinafine HCl (TBN). TBN-CSNP were prepared by nanoprecipitation method and optimized by face-centered central composite design (FCCCD). Optimized TBN-CSNP formulation exhibited a spherical shape with hydrodynamic diameter; zeta potential and entrapment efficiency (EE) of 229 ± 5 nm; 37 ± 1.5 mV; and 75 ± 2% respectively. The solid state of TBN and its compatibility with formulation ingredients were confirmed through XRD and FTIR analysis respectively. TBN-CSNP loaded P407 gel exhibited pseudoplastic rheological behavior having a spreadability of 11 ± 2 g·cm/s. The washability study showed that 40 ± 2% of the gel was eroded after washing 12 times. Drug release from TBN-CSNP- and TBN-CSNP-loaded gel was 84 ± 5% and 57 ± 3%, respectively. The cumulative quantity of TBN permeated from TBN-CSNP-loaded P407 gel and TBN-loaded P407 gel was 25 ± 8 and 27 ± 4 µg/cm2, respectively. The nail uptake study showed that 3.6 ± 0.7 and 2.1 ± 0.3 µg of rhodamine was uptaken by the nail following 2 h topical application of TBN-CSNP loaded P407 gel and TBN loaded P407 gel, respectively. Hence, the developed CSNP-based P407 gel formulation can be a potential carrier for transungual delivery of TBN to topically treat onychomycosis.

Optimization of Meloxicam Solid Dispersion Formulations for Dissolution Enhancement and Storage Stability Using 33 Full Factorial Design Based on Response Surface Methodology

This study aimed to formulate and optimize solid-dispersion of meloxicam (MX) employing response-surface-methodology (RSM). RSM allowed identification of the main effects and interactions between studied factors on MX dissolution and acceleration of the optimization process. 3³ full factorial design with 27 different formulations was proposed. Effects of drug loading percentage (A), carriers' ratio (B), method of preparation (C), and their interactions on percent MX dissolved after 10 and 30 min (Q_10min & Q_30min) from fresh and stored samples were studied in distilled water. The considered levels were 2.5%, 5.0%, and 7.5% (factor A), three ratios of Soluplus®/Poloxamer-407 (factor B). Physical mixture (PM), fusion method (FM), and hot-melt-extrusion (HME) were considered factor (C). Stability studies were carried out for 3 months under stress conditions. The proposed optimization design was validated by 3-extra checkpoints formulations. The optimized formulation was selected via numerical optimization and investigated by DSC, XRD, PLM, and in vitro dissolution study. Results showed that HME technique gave the highest MX dissolution rate compared to other techniques (FM & PM). At constant level of factor (C), the amount of MX dissolved increased by decreasing MX loading and increasing Soluplus in carriers' ratio. Actual responses of the optimized formulation were in close consistency with predicted data. Amorphous form of MX in the optimized formulation was proved by DSC, XRD, and PLM. Selected factors and their levels of the optimization design were significantly valuable for demonstrating and adapting the expected formulation characteristics for rapid dissolution of MX (Q_10min= 89.09%) from fresh and stored samples.

Application of Box-Behnken design for optimization of phenolics extraction from Leontodon hispidulus in relation to its antioxidant, anti-inflammatory and cytotoxic activities

To the best of our knowledge, there have been no phytochemical studies concerning the wild plant Leontodon hispidulus Boiss. (Asteraceae). Optimization of the green extraction process of the plant aerial parts, identification of main phenolic compounds, evaluation of antioxidant, anti-inflammatory and anticancer activities of the optimized extract have been carried out. HPLC-analysis was performed using 95% ethanolic extract. 3-Level Box-Behnken Design was applied for optimization of extraction yield and total phenolic content using 3-factors (ethanol/water ratio, material/solvent ratio and extraction time). Antioxidant, anticancer and anti-inflammatory activities were evaluated by ABTS-assay, prostate and cervical carcinoma human cell lines and carrageenan-induced rat paw edema model, respectively. HPLC-analysis showed the presence of quercetin, rutin, kaempferol, chlorogenic and ρ-coumaric acids. Increasing both ethanol/water ratio and material/solvent ratio decreased the yield, while, it increased by prolongation of the extraction time. High material/solvent ratio increased the phenolic content. The optimized extract showed high total phenolic content (104.18 µg/mg) using 201 ml of 74.5% ethanol/water at 72 h and good biological activities. Antioxidant activity was found to be 41.89 mg Trolox-equivalent/gm, with 80% free radicals inhibition. For anti-inflammatory activity, 100 mg/kg of the extract inhibited the edema in rats by 83.5% after 4 h of carrageenan injection as compared to 81.7% inhibition by indomethacin. Prostate carcinoma cell line was more sensitive to the anticancer activity of the extract than cervical carcinoma cell line (IC₅₀ = 16.5 and 23 μg/ml, respectively). The developed extraction procedure proved to be efficient in enriching the extract with phenolic compounds with promising anticancer, anti-inflammatory and antioxidant activities.

Poloxamer 407 Based Gel Formulations for Transungual Delivery of Hydrophobic Drugs: Selection and Optimization of Potential Additives

The current study aimed to develop poloxamer 407 (P407) gel for transungual delivery of antifungal hydrophobic drugs with sufficient gel strength and drug loading. Gel strength and drug loading of P407 gel was improved by use of functional additives. Hydration enhancement effect was used to select optimum nail penetration enhancer. Face-centered central composite design (FCCCD) was used to observe the effect of the selected penetration enhancer (thioglycolic acid (TGA)) and cosolvent (ethanol) on gelation behavior to develop formulation with enough loading of hydrophobic drug, i.e., terbinafine HCl (TBN), and its permeation across the nail plate without compromising on gel strength. It was observed that increasing concentration of P407 and TGA significantly reduced gelation temperature and enhanced the gel strength of P407 gel and can be used to improve P407 gel strength. Under the scanning electron microscope, the significant effect of TGA as an ungual penetration enhancer was observed on the morphology of the nail plate. Optimized P407 gel prepared with modified cold method showed a gelation temperature of 8.7 ± 0.16 °C, gel strength of 122 ± 7.5 s and drug loading of 1.2% w/w, which was four times more than the drug loading in the gels prepared with conventional cold method. Rheological behavior was pseudoplastic with 47.75 ± 3.48% of gel erosion after 12 washings and 67.21 ± 2.16% of drug release after 12 h. A cumulative amount of TBN permeated from P407 gel with and without PE after 24 h was 27.30 ± 4.18 and 16.69 ± 2.31 µg/cm², respectively. Thioglycolic acid can be used as a nail penetration enhancer without the chemical modification or addition of extra additives while retaining the gel strength. Water miscible cosolvents with moderate evaporability such as ethanol, can be incorporated to P407 gel by minor modification in method of preparation to load the required dose of hydrophobic drugs. Developed P407 gel formulation with sufficient gel strength and drug loading will be a promising carrier for transungual delivery of hydrophobic antifungal agents.

Formulation, Pharmacokinetics evaluation, and IVIVC Assessment of Gliclazide Multiparticulates in Rat Model

In vitro and in vivo studies of gliclazide (GLZ)-loaded freeze-dried alginate-gelatin (AL-GL) beads were carried out, aiming to modify its oral bioavailability. Crosslinked freeze-dried GLZ AL-GL beads (particle size: 1.5- and 3.0-mm) were prepared. In vitro evaluation of GLZ AL-GL beads included SEM, DSC, FT-IR, and release rate study in gradient media. In vivo study was single-dose (4 mg/kg), randomized, parallel-group design, two-treatment (T: test GLZ AL-GL beads and R: reference product Diamicron® 30-mg MR tablet) conducted in 96 healthy rats. Each group was subdivided into 2 sub-groups (G1 and G2) having different blood sampling schemes for up to 72 h. Assessment of level A in-vitro-in-vivo correlation (IVIVC) model was carried out. AL-GL beads successfully increased GLZ release rate compared to R. GLZ percent released (Q_4h) was 109.34, 86.85, and 43.43% for 1.5-mm and 3.0-mm beads and R, respectively. DSC analysis confirmed the interaction of AL-GL via crosslinking. No chemical interaction of GLZ has occurred as proved by FT-IR. Relative bioavailability (T/R) for AUC_0-∞ was 132.45% for G1 and 146.16% for G2. No significant differences between T and R in the primary pharmacokinetic parameters were determined. T_max values were found to be earlier in the case of G1 than those of G2. A secondary absorption peak of GLZ was clearly detected in the case of R while its sharpness was minimized in T. High IVIVC was established, and hence, the proposed in vitro release model perfectly correlated with the in vivo study. The current study design might be a platform to enable panoramic view for GLZ variability in vivo.