Development and in vitro evaluation of pH-independent release matrix tablet of weakly acidic drug valsartan using quality by design tools.

The main objective of this study was the development of pH-independent controlled release valsartan matrix tablet in Quality by design (QbD) framework. The quality target product profile (QTPP), critical quality attributes (CQAs) and critical material attributes (CMAs) were defined by science and risk-based methodologies. Potential risk factors were identified with Fishbone diagram. Following, CMAs were further investigated with a semi-quantitative risk assessment method, which has been revised with mitigated risks after development and optimization studies. According to defined critical material attributes, which one of them was determined to be the dissolution, formulation optimization study was performed by using a statistical design of experiment. Formulation variables have been identified and fixed first with a 'One factor at a time (OFAT)' approach. After OFAT studies, a statistical experimental design was conducted with the most critical material attributes. Statistical design space and mathematical prediction equations have been developed for dissolution and hardness, which is important to predict drug dissolution behavior. In conclusion, a pH-independent release has been achieved for weakly acidic drug valsartan with a deeper understanding of drug product quality, with the science and risk-based approaches of QbD tools.

Gemcitabine hydrochloride-loaded liposomes and nanoparticles: comparison of encapsulation efficiency, drug release, particle size, and cytotoxicity.

The aim of this study is to formulate and compare the physicochemical properties of negatively charged liposomes and poly(lactide-co-glycolide) (PLGA) nanoparticles loaded with gemcitabine hydrochloride. The influence of the formulation variables on the liposome and nanoparticle properties on particle size, zeta potential, encapsulation efficiency, and drug release was evaluated. Although the PEGylated nanoparticles and PEGylated liposomes were of the same size (∼200 nm), the encapsulation efficiency was 1.4 times higher for PEGylated liposomes than for PEGylated nanoparticles. The optimized formulation of PEGylated liposomes and PEGylated nanoparticles had 26.1 ± 0.18 and 18.8 ± 1.52% encapsulation efficiency, respectively. The release of drug from the PEGylated liposomes and PEGylated nanoparticles exhibited a biphasic pattern that was characterized by a fast initial release during the first 2 h followed by a slower continuous release. Transmission electron microscopy (TEM) images identified separate circular structures of the liposomes and nanoparticles. The in vitro cytotoxicity of the optimized formulations was assessed in MCF-7 and MDA-MB-231 cells, and the results showed that the cytotoxicity effect of the gemcitabine hydrochloride-loaded liposomes and nanoparticles was more than commercial product Gemko® and gemcitabine hydrochloride solution.

Bile salt-reinforced alginate-chitosan beads.

A polymeric delayed release protein delivery system was investigated with albumin as the model drug. The polysaccharide chitosan was reacted with sodium alginate in the presence of calcium chloride to form beads with a polyelectrolyte. In this study, attempts were made to extend albumin release in the phosphate buffer at pH 6.8 from the alginate-chitosan beads by reinforcing the matrix with bile salts. Sodium taurocholate was able to prevent albumin release at pH 1.2, protecting the protein from the acidic environment and extending the total albumin release at pH 6.8. This effect was explained by an interaction between the permanent negatively charged sulfonic acid of sodium taurocholate with the amino groups of chitosan. Mild formulation conditions, high bovine serum albumin (BSA) entrapment efficiency, and resistance to gastrointestinal release seem to be synergic and promising factors toward the development of an oral protein delivery form.

Cell culture and pharmacokinetic evaluation of a solid dosage formulation containing a water-insoluble orphan drug manufactured by FDM-3DP technology.

The in-vitro cytotoxicity, in-vitro permeability and in-vivo pharmacokinetics of a BCS Class-II drug - rufinamide - in a 3DP tablet formulation were evaluated. The cytotoxicity of the 3DP tablet formulation was evaluated with an MTT test; in-vitro permeability was evaluated with a Caco-2 cell culture study; and in-vivo pharmacokinetics were evaluated in Wistar albino male rats. The pharmacokinetic studies were performed following a two-sequence and single-period design approach. The highest Caco-2 permeability was obtained with the 3DP tablet formulation; and the highest cell viability was achieved with the 3DP tablet in both the Hep G2 and Caco-2 cell lines. In the in-vivo pharmacokinetic study, AUC and Cmax values were higher in the 3DP tablet formulation than in the Inovelon® film tablet at a 40 mg/kg dose. Thanks to the increased solubility of the active substance, higher in-vitro permeability and in-vivo absorption were achieved with the 3DP tablet formulation, and with lower cytotoxicity. Based on these promising findings, the 3DP tablet formulation can be considered an effective lower-dose treatment than commercial preparations.

Evaluation of chitosan/alginate beads using experimental design: formulation and in vitro characterization.

Bovine serum albumin-loaded beads were prepared by ionotropic gelation of alginate with calcium chloride and chitosan. The effect of sodium alginate concentration and chitosan concentration on the particle size and loading efficacy was studied. The diameter of the beads formed is dependent on the size of the needle used. The optimum condition for preparation alginate-chitosan beads was alginate concentration of 3% and chitosan concentration of 0.25% at pH 5. The resulting bead formulation had a loading efficacy of 98.5% and average size of 1,501 mum, and scanning electron microscopy images showed spherical and smooth particles. Chitosan concentration significantly influenced particle size and encapsulation efficiency of chitosan-alginate beads (p < 0.05). Decreasing the alginate concentration resulted in an increased release of albumin in acidic media. The rapid dissolution of chitosan-alginate matrices in the higher pH resulted in burst release of protein drug.

Improving the dissolution of a water-insoluble orphan drug through a fused deposition modelling 3-Dimensional printing technology approach.

Lennox-Gastaut Syndrome (LGS) is a rare form of childhood epilepsy. Rufinamide is an orphan drug indicated for the treatment of LGS. Three-Dimensional Printing (3DP) is a process in which solid objects are created based on a digital file by adding materials layer by layer. Fused deposition modelling (FDM) is a 3DP technique with the advantages of solid dispersion systems and the ability to use various pharmaceutical excipients in small scales, which makes this technology favorable for the production of orphan drugs. Rufinamide is a water-insoluble lipophilic compound which can exist in different polymorphic forms. The therapeutic dose is 3200 mg/day, at which rufinamide exhibits nonlinear pharmacokinetics, which may be attributed to its limited solubility. The main purpose of this paper is to improve the dissolution of rufinamide through the use of 3DP technology. For this purpose, optimum 3DP tablets were developed based on 3DP manufacturability and dissolution behaviors. The findings suggest that a mixture of hydroxypropyl methylcellulose (HPMC), Soluplus®, Kollidon® VA64, Gelucire® 48/16 and Triacetin are suitable excipients for FDM-3DP technology that can improve the dissolution of rufinamide. The optimum 3DP tablet shows significantly higher dissolution than Inovelon® at the therapeutic dose due to its improved wdissolution.

Antitumor activity of gemcitabine hydrochloride loaded lipid polymer hybrid nanoparticles (LPHNs): In vitro and in vivo.

The present study demonstrated the application of gemcitabine hydrochloride (GEM) loaded lipid polymer hybrid nanoparticles (LPHNs) for the enhancement the chemotherapeutic response. GEM, which is an anti-tumor drug, is frequently utilized for the treatment of non-small cell lung cancer, breast cancer and pancreatic cancer. GEM loaded LPHNs were formed and examined for pharmacokinetic profile and in vivo anticancer activity. Modified double emulsion solvent evaporation method was employed in the preparation of the LPHNs. Cytotoxicities of the GEM loaded LPHNs formulation were evaluated on MCF-7 and MDA-MB-231 cells by MTT assays. Pharmacokinetics and in vivo anticancer efficacy studies were conducted following intraperitoneal administration in female Sprague-Dawley rats. In vivo pharmacokinetic studies in rats exhibited the advantage of the GEM loaded LPHNs over commercial product Gemko® and the GEM loaded LPHNs had longer circulation time. The half-life of GEM in LPHNs formulation was notable advanced (4.2 folds) comparing to commercial product of GEM (native). These findings indicated that GEM loaded LPHNs can be used for enhancing antitumor efficacy for breast cancer treatment.

Development and characterization of gemcitabine hydrochloride loaded lipid polymer hybrid nanoparticles (LPHNs) using central composite design.

Lipid polymer hybrid nanoparticles (LPHNs) combine the characteristics and beneficial properties of both polymeric nanoparticles and liposomes. The objective of this study was to design and optimize gemcitabine hydrochloride loaded LPHNs based on the central composite design approach. PLGA 50:50/PLGA 65:35 mass ratio (w/w), soya phosphatidylcholine (SPC)/polymer mass ratio (%, w/w) and amount of DSPE-PEG were chosen as the investigated independent variables. The LPHNs were prepared with modified double emulsion solvent evaporation method and characterized by testing their particle size, encapsulation efficiency, and cumulative release. The composition of optimal formulation was determined as 1,5 (w/w) PLGA 50:50/PLGA 65:35 mass ratio, 30% (w/w) SPC/polymer mass ratio and 15 mg DSPE-PEG. The results showed that the optimal formulation gemcitabine hydrochloride loaded LPHNs had encapsulation efficiency of 45,2%, particle size of 237 nm and cumulative release of 62,3% at the end of 24 h. The morphology of LPHNs was found to be spherical by transmission electron microscopy (TEM) observation. Stability studies showed that LPHNs were physically stable until 12 months at 4 °C and 9 months at 25 °C/60% RH. The results suggest that the LPHNs can be an effective drug delivery system for hydrophilic active pharmaceutical ingredient.

Evaluation of alginate based mesalazine tablets for intestinal drug delivery.

The aim of this study was to develop the alginate based mesalazine tablets for intestinal delivery. Sodium alginate is a biocompatible, natural polymer with pH-sensitive gel-forming ability. Matrix tablets were prepared with two types of sodium alginate of different amounts. The in vitro release characteristics of mesalazine from alginate tablets were compared with those of the commercial product (Salofalk). X-ray imaging was used to monitor the tablets throughout the gastrointestinal system. Although alginate tablets gave a faster release in an acidic medium compared with the commercial product (Salofalk), the cumulative amount of released drug of the optimum formulation was found to be almost the same as that of the commercial product at the end of 4 h. The alginate type and amount in the matrices played an important role in basic media. The release of the optimum formulation containing low viscosity alginate was found to be almost identical to that of the commercial product in acidic and basic media. Tablets were visualized to determine whether they were located in the terminal ileum or cecum for 3-6 h. Mesalazine-alginate matrix tablet formulations can deliver the drug to the small and large intestine. Thus, the alginate matrix system may be a promising system for the treatment of Crohn's disease involving both the ileum and large intestine.

Development and validation of an in vitro-in vivo correlation for buspirone hydrochloride extended release tablets.

The aim of this study was to develop an in-vitro-in-vivo correlation (IVIVC) for two buspirone hydrochloride extended release formulations and to compare their plasma concentrations over time with the commercially available immediate release (IR) tablets. In vitro release rate data were obtained for each formulation using the USP Apparatus 2, paddle stirrer at 50 and 100 rpm in 0.1 M HCl and pH 6.8 phosphate buffer. A three-way crossover study in 18 healthy subjects studied a 30 mg "Fast" (12 h) and 30 mg "Slow" (24 h) formulation of buspirone hydrochloride given once a day, and 2x15 mg immediate release tablets dosed at a 12 h interval. The similarity factor (f(2)) was used to analyze the dissolution data. A linear correlation model was developed using percent absorbed data and percent dissolved data from the two formulations. Predicted buspirone hydrochloride concentrations were obtained by use of a curve fitting equation for the immediate release data to determine the volume of distribution and fraction absorbed constants. Prediction errors were estimated for C(max) and area under the curve (AUC) to determine the validity of the correlation. pH 6.8 at 50 rpm was found to be the most discriminating dissolution method. Linear regression analyses of the mean percentage of dose absorbed versus the mean in vitro release resulted in a significant correlation (r(2)>0.95) for the two formulations. An average percent prediction error for C(max) was -0.16%, but was 16.1%, for the AUCs of the two formulations.

In-vitro and in-vivo evaluation of mesalazine-guar gum matrix tablets for colonic drug delivery.

The aim of this study was to develop colon-specific delivery systems for mesalazine (5-ASA) using guar gum as a carrier. A colon specific matrix tablet of mesalazine with guar gum was evaluated by in vitro and in vivo X-ray studies in humans. Two different types of guar gum were used in the experiments. Tablets were prepared by the slugging method. The physical properties of tablets were tested and in vitro release studies were performed by a flow-through cell apparatus with and without galactomannanase enzyme. The type and the amount of guar gum affected the in vitro release of drug from the matrix tablets. High viscosity guar gum, in the form of a matrix tablet was capable of protecting the drug from being released in the upper region of gastrointestinal (GI) system, i.e. stomach and small intestine. X-ray imaging technique was used to monitor the tablets throughout the GI system on 8 healthy volunteers. Barium sulphate was used as a marker in the tablets for in vivo studies. These results showed that, the matrix tablets reached the colon; not being subjected to disintegration in the upper region of the GI system in all the subjects.

Propranolol hydrochloride-anionic polymer binding interaction.

Three different anionic polymers namely Eudragit S 100, Eudragit L 100-55 (methacrylic acid copolymers), and sodium carboxymethylcellulose (NaCMC) were used to evaluate the propranolol hydrochloride-anionic polymer interaction. The physical and chemical properties of propranolol hydrochloride and anionic polymer complex were investigated using Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The DSC profiles demonstrated that the characteristic peak of propranolol hydrochloride cannot be found in the heating curve of the complexes, indicating that complex is different in physicochemical properties from the physical mixture of drug-polymer. The FTIR spectra also confirmed that there is an interaction between propranolol hydrochloride and methacrylic acid copolymers. The binding of the drug to the polymers was due to the existence of preferential hydrogen bonding between the amino group of the propranolol hydrochloride and the carboxylic functions of the polymers and that pH conditions can influence this binding.