Cross-linked Polyvinylpyrrolidone Research Articles

Development and Evaluation of Venlafaxine Hydrochloride Tablets for Oral Drug Delivery Technology

Oral pills are the predominant, simple, and straightforward approach for administering drugs. The project’s primary goal is to create a pharmaceutical product that is equal in terms of its medicinal properties. A controlled-release version of the antidepressant venlafaxine hydrochloride was created and compared to the formulation currently available on the market. The launch of the branded product was assessed through an innovator and prototype evaluation. In order to develop stable and bioavailable dosage forms, it is necessary to gather pertinent data through preformulation testing. In order to create stable and bioavailable dosage forms, preformulation testing must be performed to gather relevant information among the several mixes, high-performance polymer copolymer K100M, ethyl cellulose, and cross-linked polyvinyl pyrrolidone 0.45%. The precise release mechanism could be determined by conducting in-vitro solubility tests on the created formulations and analyzing the results with a number of exponential equations. We used fourier-transform infrared (FTIR) and differential scanning calorimetry (DSC) studies to check if the polymers were compatible with the medicine.

Computer-aided optimization of carbidopa/levodopa orally disintegrating tablets

Objective This study aimed to optimize the formulation of carbidopa/levodopa orally disintegrating tablets (ODTs) in order to improve their disintegration performance, and facilitate easier medication intake for Parkinson’s patients. Method The response surface methodology (RSM) was used to optimize the formulation, with the content of cross-linked polyvinylpyrrolidone (PVPP), microcrystalline cellulose (MCC), and mannitol (MNT) as independent variables, and disintegration time as the response parameter. Python was utilized to model Carr Indices and mixing time to determine the suitable mixing time. Direct compression (DC) was used for the preparation of ODTs. Result The optimization process resulted in the following values for the independent variables: 7.04% PVPP, 22.02% MCC, and 16.21% MNT. By optimizing the mixing time using Python, it was reduced to 14.19 min. The ODTs prepared using the optimized formulation and a mixing time of 14.19 min exhibited disintegration times of 16.74 s in vitro and 17.63 s in vivo. The content uniformity of levodopa and carbidopa was found to be 100.83% and 99.48%, respectively. Conclusion The ODTs optimized using RSM and Python demonstrated excellent disintegration performance, leading to a decrease in the time the drug exists in solid form in the oral cavity. This improvement in disintegration time reduced the difficulty of swallowing for patients and enhanced medication compliance, while still ensuring that ODTs prepared by DC had sufficient mechanical strength to meet storage and transportation requirements.

TRENDING PERSPECTIVE IN EVALUATION OF INSPECTION CHARACTERISTICS OF PHARMACEUTICAL COMPOUND: COMPARATIVE STUDY OF CONTROL CHARTS

Background and objectives: The quality and efficacy of the pharmaceutical medicinal product are of paramount importance to the patients. Reproducibility and consistency of the properties of the dosage form start with the constituting ingredients either active or inactive. The present work provides an approach for the trending of one of the crucial inspection characteristics of a well-known excipient that is commonly used as a disintegrant of a water-insoluble synthetic cross-linked Polyvinyl Pyrrolidone (PVP). Establishing manufacturing criteria and quality limits should be assessed from the beginning level of the project using exploratory process-behavior plots. Materials and Methods: This study involved an assay of the initial 16 batches of the manufactured 1-ethenyl pyrrolidine-2-one expressed as a dried substance using a standard analysis method according to British Pharmacopoeia (BP). Exploratory Shewhart charts were plotted after preliminary distribution identification using Statistical Process Control (SPC) software. Based on the goodness of fit test results, the most appropriate assumed distribution was implemented in drawing the Individual/Moving Range (I/MR) control charts. Results: The goodness of fit study and probability plot showed that the most close-fitting to the data dispersion pattern was Johnson transformation to the normal spreading, smallest extreme value and Weibull distribution, respectively. While there were no alarms that could be detected from the process mean and the variability charts, further improvement is required from the supplier side to meet the benchmark minimum limit threshold, in addition, the process mean was not centered but shifted towards the Upper Control Limit (UCL). Conclusion: Implementation of SPC techniques is crucial in the modern competitive healthcare industry. Trending charts play a pivotal role in this perspective. They provide a quantitative estimation for the current situation and the actions needed for the future improvement of the monitored characteristic. Peer Review History: Received: 11 August 2023; Revised: 23 September; Accepted: 29 October, Available online: 15 November 2023 Academic Editor: Dr. Amany Mohamed Alboghdadly, Ibn Sina National College for Medical Studies in Jeddah, Saudi Arabia, amanyalboghdadly@gmail.com Received file: Reviewer's Comments: Average Peer review marks at initial stage: 6.5/10 Average Peer review marks at publication stage: 7.0/10 Reviewers: Dr. Taiwo O Elufioye, University of Ibadan, Nigeria, toonitaiwo@yahoo.com Dr. Bilge Ahsen KARA, Ankara Gazi Mustafa Kemal Hospital, Turkey, ahsndkyc@gmail.com

Fabrication of high-resolution, wide-range and low-crosstalk capacitive pressure sensing array for medical diagnosis

Flexible pressure sensors have found widespread application in medical diagnosis and human–computer interaction. These practical applications often require large-area pressure sensing arrays (PSAs) to explore spatial pressure distributions. However, the development of high-performance PSAs still presents significant challenges. Here, a new method is proposed for the fabrication of a high-resolution capacitive PSA in a 10 × 10 configuration. The array comprises the upper and lower electrode arrays of laser-induced graphene patterned on polyimide films, as well as the sandwiched dielectric units based on electrospun nanofiber membranes of H3PO4@PVPP (cross-linked polyvinyl pyrrolidone). Experimental results indicate that the PSA exhibits high sensitivity across a wide pressure range (0–200 kPa), while offering a rapid response/recovery time of 24/41 ms (at 1 kPa), an exceptionally low detection limit of ∼1.2 Pa, and a good stability of 4000 cycles. Moreover, the crosstalk of the PSA was found to be as low as 1.3%. By employing the PSA in conjunction with a convolutional neural network algorithm, a human foot-arch diagnostic system was developed for accurate detection and quantification of the plantar pressure for different types of foot arches. Such technology has significant potential in clinical detection and disease diagnosis of human foot.

Design and evaluation of gastro-swelling/gastro-floating sustained-release tablets of brivaracetam for epilepsy therapy

To prolong the absorption of the drug and achieve the effect of gastric retention, new brivaracetam tablets together with the characteristics of rapid swelling and sustained floating have been developed here. The tablets were optimized and prepared by direct compression techniques using Kollidon® SR and cross-linked polyvinylpyrrolidone (PVPP) XL as the matrix and disintegrant respectively, and carbomer 71G NF and polyethylene oxide (PEO) N60K as the gel materials to achieve sustained release effect. The characteristics of static expansion, floating time, drug release and dynamic swelling performance in vitro of the tablets were evaluated. The optimized formulations (F5 and F10) exhibited satisfactory swelling and floating properties, mechanical strength, and in vitro sustained-release characteristic with diffusion and matrix erosion mechanisms. X-ray images of beagle dogs showed that the tablet F5 could be retained in the stomach for more than 6 h. Furthermore, the pharmacokinetic studies in volunteers exhibited that the bioavailability of F5 and F10 was 95.70% (90% CI, 83.80%-109.28%) and 103.39% (90% CI, 87.61%-122.01%), respectively, relative to commercial tablets, with Tmax prolonged, demonstrating an excellent sustained-release effect. Therefore, the present system can reduce dosing frequency and improve patient compliance, which is expected to be a promising treatment option for epilepsy patients.

A review of immediate drug release dosage forms

Tablets are currently the most widely used dosage form due to their ease of self-administration, compactness, and simple production. In many situations, rapid action is necessary rather than conventional therapy. Immediate release dosage forms have become an alternative to traditional oral dose forms in order to address these shortcomings. Immediately after administration, immediate medication release dose forms dissolve more quickly. Super disintegrants such carboxymethylcellulose (Croscarmellose), sodium starch glycolate (Primogel, Explotab), cross-linked polyvinylpyrrolidone (Polyplasdone), and others are employed as the fundamental method in the manufacture of tablets. After being administered to the stomach, these powerful disintegrants instantly dissolve tablets. In this area, parenteral dosage forms and instant release liquid dosage forms have both been introduced for the treatment of patients. It is possible to administer suspensions in liquid dose form using common dispersion agents as hydroxypropyl methylcellulose, AOT (dioctyl sulfosuccinate), etc. Many medications, including neuroleptics, cardiovascular medications, analgesics, antihistamines, and other medications, can be thought of as candidates for this dose form as a result of the advent of immediate release therapy. Pharmaceutical companies frequently create a certain medication entity in a new and improved dosage form as the drug entity's patent life is about to expire. While providing its patient group with a more practical dosage form or dosing schedule, a new dosage form enables a producer to extend market exclusivity.

Formation of Dispersible Taohong Siwu Tablets.

Here, we optimize the process used to formulate and prepare dispersible Taohong Siwu tablets and provide a foundation for expanding their clinical application. Taking dispersion uniformity and disintegration time as the indices for investigation, we used a single-factor test to match and filter the excipient categories for Taohong Siwu tablets. The formulation was optimized by an orthogonal test design. The content and dissolution rates of the effective substances in dispersible Taohong Siwu tablets when prepared with optimized prescriptions were determined by ultra-high performance liquid chromatography (UPLC), and the optimal preparation process was determined. The optimal composition for dispersible Taohong Siwu tablets was 17% Taohong Siwu extract powder, 1% magnesium stearate, 49% microcrystalline cellulose, 20% cross-linked polyvinylpyrrolidone, and 13% sodium carboxymethyl starch. When dispersible Taohong Siwu tablets were prepared by direct compression and the optimized prescription powder was uniformly dispersed within 3 min, the dissolution rate reached more than 90% within 50 min.When prepared according to the optimized methods,dispersible Taohong Siwu tablets disintegrate rapidly in water with good dispersion uniformity and controllable quality.

Preparation of superabsorbent polymer gel based on PVPP and its application in water-holding in sandy soil

There have been a lot of reports on the preparation and properties of superabsorbent polymers, but there are still some problems and limitations in practical application. Therefore, a superabsorbent polymer (SAP) was synthesized by solution polymerization with tap water as reaction medium, acrylic acid and cross-linked polyvinylpyrrolidone (PVPP) as raw materials. The results of its performance and application show that the particle size was 0.425–0.85 mm, and the maximum water absorption rate of SAP in distilled water, tap water and 0.9% wt% NaCl solution was 2297 g/g, 333 g/g and 120 g/g, respectively. The water absorption rate can reach about 80% of maximum water absorption rate in 30 min. In addition, when the SAP mass addition amount was 0.56% and the particle size was 0.15–0.25 mm, the saturated moisture of sandy soil increased by 187%, the infiltration rate of sandy soil decreased by 96.7% and at 45 °C and 25 °C, the water evaporation rate of sandy soil decreased by 57.52% and 43.61%, respectively. So the material have a good application prospect in desertification and agriculture, and the way of preparation can be more effectively applied in practical production.

One-pot hydrothermal cross-linking preparation of poly(vinylpyrrolidone) immobilized silica stationary phase for hydrophilic interaction chromatography

Hydrothermally cross-linked polyvinylpyrrolidone (PVP) immobilized SiO2 stationary phase (CPVP-Sil) was prepared via a green and facile one-pot method which was demonstrated for hydrophilic interaction liquid chromatography (HILIC) as well as reverse phase chromatography(RP). A water or organic solvent-insoluble permanent CPVP immobilizing on the silica particle surface can be formed simply by dipping silica particles into PVP solution and low temperature hydrothermal treatment. The cross-linked PVP network coating on SiO2 endow it ring lactam functional groups which exhibited excellent separation ability of polar compounds by a typical HILIC retention mechanism at higher organic solvent contents (>55% ACN) and additionally polyvinyl groups for separation of alkylbenzenes in RP mode(<25% ACN). A high column efficiency of about 7 × 104 plates per meter was obtained for the test catechol compound. Remarkably, the CPVP-Sil packing materials showed good stability in acid (at pH 3.5) or basic (at pH 9.5) conditions, with 5400-fold column volumes and 3500-fold column volumes respectively.

P1101A BIFUNCTIONAL ADSORBER PARTICLE FOR THE REMOVAL OF HYDROPHOBIC UREMIC TOXINS FROM WHOLE BLOOD OF RENAL FAILURE PATIENTS

Abstract Background and Aims Hydrophobic uremic toxins accumulate in patients with chronic kidney disease, contributing to a highly increased cardiovascular risk. The clearance of these uremic toxins using current hemodialysis techniques is limited due to their hydrophobicity and their high binding affinity to plasma proteins. Adsorber techniques may be an appropriate alternative to increase hydrophobic uremic toxin removal. Method We developed an extracorporeal, whole-blood bifunctional adsorber particle consisting of a porous, activated charcoal core with a hydrophilic polyvinylpyrrolidone surface coating. The adsorption capacity was quantified using analytical chromatography after perfusion of the particles with an albumin solution or blood, each containing mixtures of hydrophobic uremic toxins. Results A time-dependent increase in hydrophobic uremic toxin adsorption was depicted and all toxins showed a high binding affinity to the adsorber particles. Further, the particle showed a sufficient hemocompatibility without significant effects on complement component 5a, thrombin-antithrombin III complex, or thrombocyte concentration in blood in vitro, although leukocyte counts were slightly reduced. Conclusion In conclusion, the bifunctional adsorber particle with cross-linked polyvinylpyrrolidone coating showed a high adsorption capacity without adverse effects on hemocompatibility in vitro. Thus, it may be an interesting candidate for further in vivo studies with the aim to increase the efficiency of conventional dialysis techniques.

Carbon dot cross-linked polyvinylpyrrolidone hybrid hydrogel for simultaneous dye adsorption, photodegradation and bacterial elimination from waste water

The creation of a polymeric hydrogel from polyvinylpyrrolidone (PVP) cross-linked by Carbon Quantum Dots (CD) for the adsorption and photocatalytic degradation of both cationic and anionic dyes. PVP, an important biocompatible constituent and often surplus in cosmetic industry, was carboxylated through NaOH refluxing and covalently conjugated to surface amine functionality of CD derived from lemon juice and Cysteamine. The hybrid hydrogel was obtained from PVP-CD covalent conjugate by careful manipulation of pH and found to possess better rheological properties than only carboxylate-PVP. The monolayer physisorption of the dyes on the hydrogel was affected by hydrogen bonding, dispersion or inductive effect, and π-π interaction with the polymer backbone as well as the CD that followed pseudo-second-order kinetics. Degradation of the adsorbed dyes was instated by the unique Reactive Oxygen Species (ROS) generating ability of the CD embedded in the hydrogel matrix upon exposure to sunlight, the mechanism of which is also unveiled. The same CD-induced ROS was found to effectively annihilate both gram-positive and gram-negative bacteria in real polluted water in less than 10 min of photoexcitation of the hydrogel. The hydrogel was restored by mild acid wash that is able to perform dye adsorption and photo-degradation upto four cycles.

UV cross-linked polyvinylpyrrolidone electrospun fibres as antibacterial surfaces

ABSTRACT Many bacteria become progressively more resistant to antibiotics and it remains a challenging task to control their overall levels. Polymers combined with active biomolecules come to the forefront for the design of antibacterial materials that can address this encounter. In this work, we investigated the photo-crosslinking approach of UV-sensitive benzophenone molecule (BP) with polyvinylpyrrolidone (PVP) polymer within electrospun fibres. The BP and PVP solutions allowed fabricating polymer mats that were subsequently functionalised with antibacterial lysozyme. The physical properties of the crosslinked electrospun fibres were investigated by scanning electron microscopy and atomic force microscopy. The average diameter of the obtained fibres decreased from 290 ± 50 nm to 270 ± 70 nm upon the addition of the crosslinking molecules and then to 240 ± 80 nm and 180 ± 90 nm after subsequent crosslinking reaction at an increasing time: 3 and 5 h, respectively. The peak force quantitative nanomechanical mapping (PF-QNM) indicated the increase of DMT modulus of obtained cross-linked fibres from 4.1 ± 0.8 GPa to 7.2 ± 0.5 GPa. Furthermore, the successful crosslinking reaction of PVP and BP solution into hydrogels was investigated in terms of examining photo-crosslinking mechanism and was confirmed by rheology, Raman, Fourier transform infrared and nuclear magnetic resonance. Finally, lysozyme was successfully encapsulated within cross-linked PVP-BP hydrogels and these were successfully electrospun into mats which were found to be as effective antibacterial agents as pure lysozyme molecules. The dissolution rate of photo cross-linked PVP mats was observed to increase in comparison to pure PVP electrospun mats which opened a potential route for their use as antibacterial, on-demand, dissolvable coatings for various biomedical applications.

Preparation and characterization of wet-milled cyclovirobuxine D nanosuspensions

This study aims to develop nanosuspensions for improving the dissolution of poorly water-soluble cyclovirobuxine D (CVB-D) containing a binary stabilizer system and further characterize the stabilization potential and physical–chemical variables of CVB-D nanosuspensions. Binary stabilizers of croscarmellose sodium (CCS) with hydroxypropyl methyl cellulose acetate succinate (HPMCAS), hydroxypropyl β cyclodextrin (H-β-CD) and cross-linked polyvinylpyrrolidone (CP) were chosen for nanosuspensions. The rapid dissolution of CVB-D nanosuspensions was achieved by wet media milling. By observing the stability after 30 days of storage, the combination of CCS with HPMCAS was determined to be the most effective binary system. The relative order of effectiveness of the combinations was as follows: CCS/HPMCAS > CCS/CP > CCS/H-β-CD. The obtained particle size and polydispersity index were both within an acceptable range. The particle surface morphology, miscibility, thermal stability and molecular binding energy of CVB-D nanosuspensions were subsequently characterized by SEM, FTIR, TG-DSC and NMR spectroscopy. The results revealed that smaller particle size and better miscibility have a significant contribution to the dissolution and stability of CVB-D nanosuspensions. Overall, these promising results open new perspectives for improving the stability and dissolution rate for CVB-D and other alkaloids.

Solvent-Free Graft-From Polymerization of Polyvinylpyrrolidone Imparting Ultralow Bacterial Fouling and Improved Biocompatibility.

Polymer grafting has been a powerful tool in the surface modification of biomaterials. Traditional solvent-based grafting, however, often requires laborious procedures taken under harsh conditions, which seriously hinders its practical applications. Here, we report a facile solvent-free graft-from method that is able to achieve a superior surface functionality as compared to most reported results from traditional solvent-based grafting. The grafting was proceeded by conformally coating a cross-linked polyvinylpyrrolidone (PVP) prime layer in the vacuum, immediately followed by in situ grafting of PVP homopolymer chains from the propagating sites on the coating surface. The resultant coating exhibited enriched surface pyrrolidone content compared to the single-layer cross-linked counterpart and a water contact angle of 22°, lower than most reported PVP-grafted surfaces. Medical catheters grafted with PVP achieved a more than 99.9% bacterial antifouling enhancement compared to the pristine catheter, and significantly improved biocompatibility during a 4 week in vivo test in mice. The achieved surface functionality is attributed to the synergistic effect from the functional groups distributed both on the grafted chains and on the cross-linked primer. The effectiveness and simplicity of the vapor grafting method thus suggest a promising surface modification route for biomaterials and beyond.

A Bifunctional Adsorber Particle for the Removal of Hydrophobic Uremic Toxins from Whole Blood of Renal Failure Patients.

Hydrophobic uremic toxins accumulate in patients with chronic kidney disease, contributing to a highly increased cardiovascular risk. The clearance of these uremic toxins using current hemodialysis techniques is limited due to their hydrophobicity and their high binding affinity to plasma proteins. Adsorber techniques may be an appropriate alternative to increase hydrophobic uremic toxin removal. We developed an extracorporeal, whole-blood bifunctional adsorber particle consisting of a porous, activated charcoal core with a hydrophilic polyvinylpyrrolidone surface coating. The adsorption capacity was quantified using analytical chromatography after perfusion of the particles with an albumin solution or blood, each containing mixtures of hydrophobic uremic toxins. A time-dependent increase in hydrophobic uremic toxin adsorption was depicted and all toxins showed a high binding affinity to the adsorber particles. Further, the particle showed a sufficient hemocompatibility without significant effects on complement component 5a, thrombin-antithrombin III complex, or thrombocyte concentration in blood in vitro, although leukocyte counts were slightly reduced. In conclusion, the bifunctional adsorber particle with cross-linked polyvinylpyrrolidone coating showed a high adsorption capacity without adverse effects on hemocompatibility in vitro. Thus, it may be an interesting candidate for further in vivo studies with the aim to increase the efficiency of conventional dialysis techniques.

Anchoring Pd Nanoparticles on Fe3O4@SiO2 Core–Shell Nanoparticles by Cross-Linked Polyvinylpyrrolidone for Nitrite Reduction

A novel and environmentally benign approach was developed to create a Fe3O4@SiO2 core–shell structure supported Pd catalyst consisting of a superparamagnetic Fe3O4 nanosphere core, a SiO2 shell with a rough surface, Pd nanoparticles deposited on a SiO2 shell, and a cross-linked polyvinylpyrrolidone (PVP) layer. It was found that both adsorbed PVP and SiO2 shell with a rough surface from the surface-protected etching process were critical to obtain the uniform PdO deposition, while the cross-linked PVP layer could effectively anchor and protect active Pd nanoparticles to enhance their stability to resist detachment from the catalyst support and improve the reusability of the catalyst. Because of its superparamagnetic behavior, it could disperse well in aqueous solution without external magnetic field and be separated easily from aqueous solution when an external magnetic field was present. It demonstrated a high catalytic activity, desirable N2 product selectivity over 99.7%, and good reusability for the c...

Effect of Sulfites on Antioxidant Activity, Total Polyphenols, and Flavonoid Measurements in White Wine.

Polyphenols content and antioxidant activity are directly related to the quality of wine. Wine also contains sulfites, which are added during the winemaking process. The present study aimed to evaluate the effects of sulfites on the assays commonly used to measure the antioxidant activity and polyphenols and flavonoids content of white wines. The effects of sulfites were explored both in the standard assays and in white wine. The addition of sulfites (at 1–10 μg) in the standard assays resulted in a significant, positive interference in the Folin–Ciocalteu’s assay used for polyphenols measurements and in both the Ferric Reducing Antioxidant Power and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt radical cation decolorization assays, which were used for antioxidant activity evaluation. A negative interference of sulfites (at 1–20 μg) was observed for the colorimetric aluminium-chloride flavonoids assay. The addition of sulfites to organic white wines (at 25–200 mg/L wine) clearly resulted in a significant overestimation of antioxidant activity and polyphenols content, and in an underestimation of flavonoids concentration. To overcome sulfite interferences, white wines were treated with cross-linked polyvinylpyrrolidone. The total polyphenols content and antioxidant activity measurements obtained after polyvinylpyrrolidone treatment were significantly lower than those obtained in the untreated wines. Flavonoids were expected to be higher after polyvinylpyrrolidone treatment, but were instead found to be lower than for untreated wines, suggesting that in addition to sulfites, other non-phenolic reducing compounds were present in white wine and interfered with the flavonoid assay. In view of our results, we advise that a purification procedure should be applied in order to evaluate the quality of white wine.

Hydrogel-embedded nanocrystalline hydroxyapatite granules (elastic blocks) based on a cross-linked polyvinylpyrrolidone as bone grafting substitute in a rat tibia model.

PurposeThe aim of this study was to examine the in vivo characteristics and levels of integration and degradation of a ready-to-use bone grafting block with elastic properties (elastic block) for the use in surgery.Materials and methodsThirty-six male Wistar rats underwent surgical creation of a well-defined bone defect in the tibia. All created defects – one per animal – were filled with an unsintered nanocrystalline hydroxyapatite embedded either with a non-cross-linked hydrogel carrier (CONT, n=18) or a cross-linked hydrogel carrier (elastic block [EB], n=18) based on polyvinylpyrrolidone (PVP) and silica sol, respectively. The animals were killed after 12 (n=12), 21 (n=12) and 63 days (n=12). The bone formation and defect healing were quantified by histomorphometric measurements made in paraffin sections. Additionally, immunohistochemical (tartrate-resistant acid phosphatase [TRAP] and alkaline phosphatase [aP]), antibody-based examinations (CD68) and energy-dispersive x-ray scattering measurements of silica atom concentration were carried out.ResultsA larger remaining bone defect area overall was observed in EB after 12 days and 21 days. After 63 days, similar areas of remaining bone defects were found. The amount of the remaining carrier material in EB overall was higher at all times. In CONT no residual carrier material was found at 12 days and later. CD68 analyses showed significantly lower level of CD68-positive marked cells after 21 days in CONT, and nonsignificant differences at 12 and 63 days, respectively. Additionally, a significantly higher level of aP-positive marked cells was observed in CONT after 12 days. Later on, the levels of aP-positive marked cells were slightly higher in EB (21 and 63 days). Furthermore, no significant differences regarding the level of TRAP-positive marked cells in each group were observed.ConclusionThe bone substitute (EB) with the cross-linked PVP-based hydrogel carrier leads at the beginning to a higher amount of remaining carrier material and remaining bone substitute. This delayed degradation is supposed to be the reason for the observed lower level of bone remodeling and is caused by the irradiation changes (cross links) in the structure in PVP.

Preparation and release mechanism of tectorigenin intragastric floating sustained-release tablets

To investigate the preparation technology and release mechanism of tectorigenin intragastric floating sustained-release tablets. The tablet was produced by wet granulation compression method, with hydroxypropyl methyl cellulose (HPMCK15M), cross-linked polyvinyl pyrrolidone (PVPP), octadecanol and sodium bicarbonate as excipient. The prescriptions were screened and optimized by orthogonal experimental design with in vitro floating capacity and drug release characteristics as the evaluation indexes. The optimization results were as follows: tectorigenin 33.3%, HPMCK15M 16.7%, PVPP 20.0%, octadecanol 13.3%, sodium bicarbonate 5%, and starch gel 10.7%. The prepared tablet can be floated within 10 s in the artificial gastric juice, lasting for 12 h in vitro, with a cumulative release rate of 70% in 10 h. The analysis of Rritger-Peppas equation showed that the sustained-release tablet had two advantages of both drug diffusion and skeleton dissolution. The tablet had good appearance and compressibility, as well as favorable floating capacity and drug release characteristics.

Preparation, optimization and in vitro–in vivo investigation for capsules of the choline salt of febuxostat

The objective of the present study was to exhibit the enhanced water-solubility and in vivo oral absorption when febuxostat (FXT) became the salt formation of choline. The formation of the choline salt of febuxostat was confirmed by X-ray powder diffraction, infrared spectroscopy analysis and differential scanning calorimetry. The direct filling method was used to develop a capsule formulation. Cellactose 80 was used as the filler due to its good fluidity, while cross-linked polyvinylpyrrolidone (PVPP) and magnesium stearate (MS) were used as the disintegrant and lubricant, respectively. Then the in vitro release of the formulation was carried out in five different dissolution media including HCl solution (pH 1.2), acetate buffer (pH 4.5), phosphate buffer (pH 6.8 and pH 7.2) and water. Evident improvement of release for choline febuxostat (CXT) was presented in water while the dissolution degree was decreased for CXT in the medium of phosphate buffer (pH 6.8) in comparison with FXT. Furthermore, the pharmacokinetics of CXT was studied in rats using UPLC-MS/MS compared with FXT. The data acquired illustrated that AUC0-24h of CXT and FXT were 22,245.96 ± 7342.92 µg⋅h/l and 12,249.70 ± 2024.04 µg⋅h/l, respectively. The relative bioavailability of CXT to FXT was about 181.6% and the P value of AUC0-24h was less than 0.05. It showed significant difference between the two drugs after oral administration. In conclusion, the water-solubility and oral bioavailability were both improved remarkably for the choline salt of febuxostat and choline salinization was proved an effective way to increase the in vivo absorption for FXT.