Mixture Of Microcrystalline Cellulose Research Articles

A model design for managing technological parameters at the stage of the pharmaceutical development of antidiabetic drugs in the form of solid dosage forms

Aim. To develop a model for managing technological parameters at the stage of the pharmaceutical development of an antidiabetic drug in tablets with API of SGLT-2 class – a derivative of gliflozin. Materials and methods. In the study conducted, the methods of system and comparative analysis, generalization, statistical processing and synthesis were used in determining the projected prospects, design, modeling, mathematical modeling, tabular and graphic means of presenting the results. To implement the goals and objectives of the study, software and electronic resources of the Anatomical Therapeutically Chemical Classification System (ATC), Biopharmaceutical Classification System (BCS), Compendium, State Register of Medicines of Ukraine were used; statistical data and data from clinical studies of the content were as follows: https://www.wipo.int; https://www.dec.gov.ua; https://www.clinicaltrials.gov; https://www.ncbi.nlm. nih.gov; https://eacpt.org; https://bpspubs.onlinelibrary.wiley.com. The study was conducted on the modern equipment for determining the bulk density (ERWEKA SVM 202, Germany), the flowability of powders (ERWEKA GT, Germany), resistance to crushing (ERWEKA TBH-525 WTO, Germany), friability (ERWEKA TAR 200, Germany), disintegration (ERWEKA ZT 33, Germany). The active ingredient in tablets of the antidiabetic drug is API calculated with reference to the content of dapagliflozin, 5 mg. The following excipients from the groups of fillers (factor A) were used: a1 – microcrystalline cellulose (MCC) of grade 200, a2 – lactose monohydrate of grade 80, a3 – a mixture of MCC of grade 102 with anhydrous lactose of grade 22 AN in the ratio of 3:1; disintegrants (factor B): b1 – crospovidone XL-10, b2 – sodium croscarmellose, b3 – sodium starch glycolate, glidants (factor C): c1 – colloidal anhydrous silicon dioxide (aerosil 200), c2 – talc, c3 – polyethylene glycol (PEG) 8000, as well as magnesium stearate as a lubricant. The experimental data were subjected to statistical processing by the method of variance analysis. Results and discussion. The development and introduction of new pharmaceuticals, effective analogs and generics is an important task as it contributes to the improvement of the quality of drug supply, treatment and safe use for patients with diabetes mellitus. A model for managing technological parameters at the stage of the pharmaceutical development has been developed; the target quality profile of the antidiabetic drug and tablets with API of SGLT-2 class – a derivative of gliflozin has been substantiated, and critical quality indicators have been determined. According to the model proposed, the optimal composition and technology of antidiabetic tablets with API of SGLT-2 class – a derivative of gliflozin calculated with reference to dapagliflozin, 5 mg, have been developed using an experiment planning matrix based on a 3*3 hyper-Greek-Latin square of the second order; the excipients have been selected; the effect of qualitative and quantitative factors and technological parameters on the pharmaco-technological properties of the tablet masses studied and tablet quality indicators, as well as critical indicators of the quality of the pharmaceutical product have been determined. Experimental studies and risk assessment have been carried out; based on the results, the optimal parameters of the technological process for the production of the antidiabetic drug in tablets with API of SGLT-2 class – a derivative of gliflozin – dapagliflozin have been substantiated. Conclusions. Based on the results of the system analysis of the application of mathematical models in the production of pharmaceutical forms, it has been determined that mathematical modeling is a key stage for ensuring the quality of the technological process at the stage of the pharmaceutical development of an antidiabetic drug in tablets with API of SGLT-2 class – a derivative of gliflozin. The use of mathematical modeling in the course of the pharmaceutical development allows optimization at the stage of the experimental research of API, its polymorphic form, physico-chemical properties and pharmaco-technological indicators. A model for managing technological parameters at the stage of the pharmaceutical development has been proposed; the target quality profile of the antidiabetic drug and tablets with API of SGLT-2 class – a derivative of gliflozin has been substantiated; the optimal composition and technology of this pharmaceutical product has been developed.

Biofouling-focused assessment of a novel, cellulose-based ionogel membrane applied in a microbial fuel cell

In this work, a novel ionogel membrane was prepared on polyethersulfone physical support from the mixture of microcrystalline cellulose and [BMIM][Cl] (1-Butyl-3-methylimidazolium chloride) ionic liquid and used in a microbial fuel cell (MFC). The ionogel membrane was characterized in terms of its morphology, mass- (substrate, oxygen) and ion transfer features and compared to Nafion 115. The membranes were deployed in acetate-fed two-chamber MFC, where the MFC equipped with the ionogel membrane showed a Coulombic efficiency and peak current density of 49.4 % and 369 mA m−2, respectively. Through three weeks of experiments, the electrode and membrane biofouling layers were studied by 16S amplicon metagenomics and correspondence analysis. It turned out that a cellulose-degrading species, Clostridium termitidis was present with a relatively large, 23.2 % relative abundance on the surface of the ionogel membrane, which may have caused its deterioration and the consequent colonization of the cathodic compartment.

Molecular and qualitative characterization of compatibility between valacyclovir hydrochloride and excipients as raw materials for the development of solid oral dosage formulation

Objectives: The objective of this present study is to know the compatibility of valacyclovir hydrochloride (VCH) with common excipients that would be utilized to develop solid oral dosage forms. Several spectroscopy techniques were used to know the possible interactions of VCH with excipients. More, a molecular docking study was also carried out to see the interaction of VCH with excipients. In vitro study of a physical mixture of VCH with excipients was executed to know the release of a drug. Material and Methods: Several analytical techniques such as differential scanning calorimetry, nuclear magnetic resonance spectrometer, and Fourier-transform infrared (FTIR) spectroscopy have been utilized to know the drug-excipient compatibility. Further, possible interactions between valacyclovir and different excipients were assessed by thin-layer chromatography. In vitro dissolution studies in different sets of experiments were done to determine the influence of the hydrophobic and hydrophilic nature of excipients (on the dissolution profile of VCH using USP II-type dissolving apparatus). Moreover, in silico molecular docking studies were also done to know any possible molecular interactions among drugs and excipients using AutoDock VINA 1.2.0 software and GROMACS 5.0 software. Results: FTIR and 1H NMR spectra of VCH and physical mixtures of VCH and excipients were compared and it was observed that no significant deviation of characteristic peaks in infrared spectroscopy and 1H NMR signals was detected. The endothermic peak of VCH in the physical mixtures of drugs and excipients was found in approximately the same position. In vitro dissolution studies displayed the influence of the hydrophobic and hydrophilic nature of excipients on the dissolution profile of VCH. For the physical mixture of VCH with lactose (LAC) and dicalcium phosphate (DP), % drug release was found to be 31.96% and 33.16% at 10 min, whereas the amount of % drug released for the mixture of VCH and talc was 25.00%. For two other excipients such as LAC and DP, the % drug release was determined to be 42.96% and 41.64%, respectively, for 30 min. The docking study also provided insights into the lowest energy conformations. Docking study anticipated that the number of interactions were more between valacyclovir and LAC (four nos.) in comparison to valacyclovir and microcrystalline cellulose (MCC) (two nos.). This interaction showed that in vitro drug release for the physical mixture of VCH with MCC was higher than a mixture of valacyclovir with LAC. Conclusion: A compatibility study of VCH by analytical techniques established that VCH was compatible with utilized excipients. Drug dissolution of VCH and physical mixture of MCC exhibited the maximum amount of drug release whereas a mixture of VCH with magnesium stearate released the minimum amount of drug for both short (10 min.) and long (30 min.) period. Docking studies disclosed that the LAC complex showed less deviation with less root mean square deviation value in comparison to the microcrystalline complex. Thus, the LAC complex has more hydrogen bonds and it was more stable as compared with the MCC complex. Therefore, VCH and used excipients could be used for solid dose formulations.

A comprehensive compatibility study of ganciclovir with some common excipients

Objectives: The aim of the present study is to illustrate compatibility testing of ganciclovir (GCV) with some common excipients that would be used to manufacture solid oral dosage forms. Different spectroscopy techniques were utilized to see the interaction of GCV with excipients such as lactose, microcrystalline cellulose (MCC), magnesium stearate, and talc, and dicalcium phosphate. Further, a molecular docking study was also done to know the interaction of GCV with excipients. In vitro study of a physical mixture of GCV with excipients was performed to get the release of drug. Material and Methods: A number of analytical techniques (differential scanning calorimetry [DSC] using DSC-Q20, TA instruments, Fourier-transform infrared spectroscopy [FTIR] spectroscopy using Spectrum RX 1, nuclear magnetic resonance [NMR] using Bruker Advance Neo 500 MHz NMR spectrometer, etc.) have been used to explore the drug-excipient compatibility. Further, a suspected interaction was evaluated by thin-layer chromatography (TLC). In vitro dissolution studies in different sets of experiments were accomplished to determine the influence of hydrophobic and hydrophilic attributes of excipients (MCC, lactose, dicalcium phosphate, and talc) on the dissolution profile of GCV using USP1-type dissolution apparatus. Furthermore, in silico molecular docking studies were also performed to evaluate any probable molecular interactions among drugs and excipients using Auto Dock VINA 1.2.0 software and GROMACS 5.0 software. Results: Comparing FTIR and 1H NMR spectra of GCV and physical mixtures of GCV and excipients, no significant deviation of characteristic peaks in infrared spectroscopy and 1H NMR signals was observed. The DSC of GCV showed two sharp endothermic peaks at 238.82°C and 255°C. The endothermic peak of GCV in DSC thermogram of physical mixtures was observed in nearly the same position except with lactose and dicalcium phosphate. A slightly deviated peak of GCV with a physical mixture of drug and lactose and dicalcium phosphate indicated that there were suspected interactions between the drug with lactose and dicalcium phosphate. These interactions were evaluated by thin-layer chromatography (TLC) and it confirmed that there was no interaction between drugs and excipients. In vitro dissolution studies determined the influence of hydrophobic and hydrophilic attributes of excipients on the dissolution profile of GCV. The physical mixture of GCV with MCC displayed a maximum amount (66.48%) of drug release in 10 min. On the other hand, a physical mixture of GCV with talc showed a minimum amount (12.08%) of drug release in 10 min. Docking study predicted that the number of interactions were more between GCV and lactose (four nos.) in comparison to GCV and MCC (two nos.). This interaction supported the in vitro drug release of a physical mixture of GCV with MCC which was higher than a mixture of GCV with lactose. Conclusion: Compatibility testing of GCV with used excipients by analytical techniques confirmed that GCV should be compatible with used excipients. Drug dissolution of GCV and physical mixture of MCC exhibited the maximum amount of drug release whereas a mixture of GCV with talc released the minimum amount of drug for both short (10 min.) and long (60 min.) periods. Docking studies disclosed that the lactose complex showed less deviation with less root mean square deviation value in comparison to the microcrystalline complex. Thus, the lactose complex has more hydrogen bonds and it was more stable as compared with the MCC complex. GCV indicates that the total energy of the MCC complex is less than that of the lactose complex. This indicates that GCV is more soluble when combined with the microcrystalline complex. Therefore, GCV and used excipients could be used for solid dosage formulations.

4D study of liquid binder penetration dynamics in pharmaceutical powders using synchrotron X-ray micro computed tomography

The properties of pharmaceutical powders, and the liquid binder, directly influence the penetration behavior in the wet granulation process of the pharmaceutical industry. Conventional methods encounter challenges in understanding this fast process. In this work, an emerging synchrotron-based X-ray imaging technique (having fast imaging capability) was employed to investigate the internal process from 2D and 3D to real-time (in-situ with ms time intervals) 3D (also considered 4D) perspectives. Two commonly used excipients (lactose monohydrate (LMH) and microcrystalline cellulose (MCC)) were used to make binary mixtures with acetaminophen (APAP) as the active pharmaceutical ingredient (API). Isopropanol and water were employed as liquid binders in the single droplet impact method. Results showed that for most of the mixtures, the porosity increased at higher fractions of APAP. MCC mixtures experienced less agglomeration and more uniform pore distribution than LMH ones, resulting in a faster droplet penetration with isopropanol. Moreover, the imbibition-spreading studies showed that isopropanol penetration in MCC powders followed more unidirectional vertical movement than horizontal spreading. Our results also demonstrated that simultaneous granulation of LMH with water resulted in much slower penetration. This study revealed that synchrotron X-ray imaging can investigate 3D internal pore structures and how they affect the quantitively real-time internal penetration dynamics.

[Development of an improved virus plaque assay based on avicel].

Avicel is made of a mixture of microcrystalline cellulose (MCC) and carboxymethyl cellulose (CMC), and used for virus plaque assay. The avicel in common use is produced by FMC Biopolymer. Due to the relatively fixed proportion of MCC and CMC, avicel in common use is not suitable for plaque determination experiment of all types of viruses. In this study, we evaluated the effect of avicel made of different proportions of MCC and CMC on virus plaque assay, and developed an improved avicel virus plaque assay featured with simple and convenient operation, good practicability and high stability. To generate avicel overlays with different proportions of MCC and CMC, twelve different 2×avicel solutions were prepared. Their overall viscosity and bottom viscosity were measured to evaluate the ease of operation. The results showed that most of the 2×avicel solutions (except the 4.8% MCC+1.4% CMC and 4.8% MCC+1.0% CMC group) were easy to absorb and prepare nutrient overlap than 2×CMC solution. In order to find the best scheme to detect the titer of porcine epidemic diarrhea virus (PEDV), these avicel overlay solutions with different proportion of MCC and CMC were used as a replacement in the standard plaque assay. By comparing the size, clarity, stability and titer accuracy of virus plaque, we identified that 0.6% MCC and 0.7% CMC was the most preferable composition of avicel overlay for PEDV plaque assay. In conclusion, we developed an improved virus plaque assay based on avicel, which may facilitate the research of virus etiology, antiviral drugs and vaccines.

Predictive modelling of powder compaction for binary mixtures using the finite element method

Despite the widespread use of solid-form drug delivery within the pharmaceutical industry, tablets remain challenging to formulate because their properties depend strongly on the powder composition and details of the compaction process. Powder compaction simulations, using the finite element method (FEM) in combination with the density-dependent Drucker-Prager Cap model, can be used to aid the design process of pharmaceutical tablets. Parametrisation is typically carried out manually and requires experimental data for each powder considered. This becomes cumbersome when considering different ratios of component powders. An automated parameterisation workflow was developed and validated using experimental powder mixtures of micro-crystalline cellulose and dibasic calcium phosphate dihydrate. FEM simulations reproduced experimental compaction curves with a mean error of 2.5% of the maximum compaction pressure. Moreover, a mixing methodology was developed to estimate parameters of mixtures using only pure-component parameters as input. The experimental compaction curves of mixtures were predicted with a mean error of 4.8%.

Terahertz time-domain spectroscopy as a novel tool for crystallographic analysis in cellulose: the potentiality of being a new standard for evaluating crystallinity

Given that terahertz (THz) radiation responds to intermolecular forces such as hydrogen bonds, THz time-domain spectroscopy (THz-TDS) has expanded possibilities in cellulose research. In this study, THz-TDS was used to investigate the crystallinity of three types of cellulose-based materials. Microcrystalline cellulose (MCC) and wood were ball milled at different times, and pseudo-wood was a mixture of MCC and lignin of different mass fractions. All the samples showed peaks at 3.04 THz in the THz mass absorption coefficient spectra. Further, the spectra from 2.79 THz to 3.32 THz were cut out and detrended by subtraction from a baseline. The integrated intensity of the detrended spectra showed a correlation with the mass fraction of lignin of the pseudo-wood samples, and ball milling time of the MCC and wood samples. The correlation was similar with the crystallinity index calculated from X-ray powder diffraction. Moreover, the original wood sample without ball milling had an integrated intensity that was about 30% that of the original MCC sample, matching with the cellulose concentration of the wood (about 30% to 40%). We normalized the integrated intensity of 2.79 THz to 3.32 THz into 1 to 0 by a min–max algorithm and proposed a new “index” for evaluating crystallinity.

Quantitative Estimation of Avicel Polymer and its Impact on Spray Pattern, Plume Geometry and Droplet Size in Nasal Spray Products

Throughout the world, the regulatory agencies like US FDA, MHRA, Health Canada recommend that during the development of generic products like Nasal sprays, Ophthalmic solutions, the inactive ingredients in the generic product formulation must be qualitatively (Q1) and quantitatively (Q2) similar to the reference listed drug product. This requires a careful deformulation/reverse engineering study of the reference listed drug product or innovator product for all the listed inactive ingredients. Avicel is one of the most important ingredients primarily used in various Nasal spray and ophthalmic suspension products as a suspending agent. It is a mixture of microcrystalline cellulose and carboxy methyl cellulose. The aim of this study is to develop a simple yet robust analytical method for the accurate quantitative estimation of this polymer for generic product development to regulatory markets. We have not found any reported method for the accurate quantitation of this polymer from any of the pharmaceutical dosage forms. Hence, this article will certainly accelerate the generic development of different pharmaceutical dosage forms for regulatory markets. Due to its non chromophoric nature, Avicel polymer is derivatized to a readily quantifiable compound by using diphenylamine reagent. The complex is measured at wavelength 635 nm without any interference. The polymer can be successfully quantified at concentration of 0.26 μg/ml and above from various pharmaceutical products such as tablets, nasal spray suspensions, ophthalmic products etc. This paper gives a simple yet accurate and precise method for the quantitative estimation of Avicel by derivatized spectrophotometry from various pharmaceutical products.

Second-Generation Phosgene and Diphosgene Detection Tube

We have developed a second-generation detection tube for colorimetric and fluorescence detection of phosgene and diphosgene in air. The tube is packed with pellets made of a mixture of microcrystalline cellulose and magnesium aluminum metasilicate treated with a suitable monoterpene (camphor, menthol) to increase porosity and specific surface area. We impregnated the pellets with a specific o-phenylenediamine-pyronin (PY-OPD) based reagent. The detector with this novel indication charge enables phosgene or diphosgene to be selectively and sensitively detected at concentrations lower than as would those posing acute health risk. Owing to the analytical colorimetric and, at the same time, fluorescence signal, the detector is very robust while featuring good sensitivity and variability. The colorimetric limits of detection were 0.3 mg/m3 (tristimulus colorimeter), resp. 5 mg/m3 (with the naked eye), fluorescence detection limits of 0.3 mg/m3 (with the naked eye), all at an air sample volume of 1 dm3. The response was practically immediate, acid vapors and gases, or diethyl chlorophosphate as a simulant of nerve warfare chemical agents, were disruptive.

Improvement in physical and thermal stability of cloudy ginkgo beverage during autoclave sterilization: Effects of microcrystalline cellulose and gellan gum

This work aimed to apply microcrystalline cellulose (MCC) and gellan gum to improve the physical and thermal stability of cloudy ginkgo beverages. The stability of each beverage samples was characterized in terms of particle size, size distribution, zeta potential, rheological properties, Turbiscan Stability Index (TSI), and changes in backscattered light intensity (△BS). Our results indicate that an irreversible phase separation occurred in the beverage sample, induced by increased particle size, decreased zeta potential, and decreased viscosity during the sterilization process. Although the addition of either MCC or gellan improved beverage stability by decreasing particle size and increasing zeta potential, this improvement was limited; the aggregation and sedimentation of suspended particles still occurred, as revealed by large △BS and TSI changes. Beverage samples added with a mixture of MCC and gellan exhibited different physical and thermal stability values depending on the ratio of MCC to gellan. The addition of MCC (0.3%, w/w) combined with a small amount of gellan (0.05% or 0.08%, w/w) effectively prevented drastic thermal damage and improved physical and thermal beverage stability in comparison to MCC combined with the larger amount of gellan. This study provides some suggestions for the industrial production of cloudy beverages.

FORMULATION AND EVALUATION OF ORODISPERSIBLE TABLETS OF DONEPEZIL HYDROCHLORIDE

Objective: The present study was aimed to develop the formulation and in vitro evaluation of Orodispersible tablets by wet granulation method using Donepezil HCl as a model drug to enhance patient compliance.
 Methods: In the wet granulation method, a mixture of microcrystalline cellulose and hydroxypropyl methylcellulose were used along with superdisintegrants, i.e., croscarmellose sodium and crospovidone. The prepared granules were subjected to both pre and post-compression evaluation parameters including; FTIR spectroscopy, micromeritics properties, tablet weight variation, hardness, friability, drug content, disintegration time and in vitro drug release.
 Results: FTIR studies indicated that there was nointeraction between the drug and the excipients used. The formulation containing high concentration of crospovidone and mixture as the best formulation F2 based on in vitro drug release characteristics of tablet formulation.
 Conclusion: The results of this work suggested that orodispersible tablets of Donepezil hydrochloride with rapid disintegration time, fast drug release and good hardness can be efficiently and successfully formulated by wet granulation method.

Tableting properties of microcrystalline cellulose obtained from wheat straw measured with a single punch bench top tablet press

The objective of this work was to study the relation between the manufacturing conditions of microcrystalline cellulose (MCC), its physicochemical properties and its tableting behavior. Two different preparation procedures were used to produce MCC from wheat straw, utilizing an acid hydrolysis method, either using only sulfuric acid or combination of sulfuric and hydrochloric acid. The tableting behavior of obtained MCC samples and mixtures of MCC with ibuprofen was studied using a dynamic powder compaction analyzer. It was observed that some of the obtained MCC samples showed better flowing properties than commercially available Vivapur® PH101 and also very high values of tensile strength, solid fraction and elastic recovery. This can be linked with its good compaction behavior, but on the other hand it can cause problems with the disintegration of the tablets. In mixtures with ibuprofen, MCC samples showed lower values of tensile strength, while on the other hand elastic recovery did not seem to be much affected, still exhibiting very high values. According to the obtained results, it can be concluded that MCC obtained from the agricultural waste could have satisfactory properties for tablet preparation by the direct compression method. Further studies are needed to optimize process conditions in order to achieve better physicochemical characteristics, especially in terms of elastic recovery.

Dissolution Behavior of Flufenamic Acid in Heated Mixtures with Nanocellulose

Flufenamic acid (FFA) is a problem drug that has up to eight different polymorphs and shows poor solubility. Variability in bioavailability has been reported in the past resulting in limited use of FFA in the oral solid dosage form. The goal of this article was to investigate the polymorphism and amorphization behavior of FFA in non-heated and heated mixtures with high surface area nanocellulose, i.e., Cladophora cellulose (CLAD). As a benchmark, low surface area microcrystalline cellulose (MCC) was used. The solid-state properties of mixtures were characterized with X-ray diffraction, Fourier-transform infrared spectroscopy, and differential scanning calorimetry. The dissolution behavior of mixtures was studied in three biorelevant media, i.e., fasted state simulated gastric fluid, fasted state simulated intestinal fluid, and fed state simulated intestinal fluid. Additional thermal analysis and dissolution tests were carried out following 4 months of storage at 75% RH and room temperature. Heated mixtures of FFA with CLAD resulted in complete amorphization of the drug, whereas that with MCC produced a mixture of up to four different polymorphs. The amorphous FFA mixture with CLAD exhibited rapid and invariable fasted/fed state dissolution in simulated intestinal fluids, whereas that of MCC mixtures was highly dependent on the biorelevant medium. The storage of the heated FFA-CLAD mixture did not result in recrystallization or changes in dissolution profile, whereas heated FFA-MCC mixture showed polymorphic changes. The straightforward dry powder formulation strategy presented here bears great promise for reformulating a number of problem drugs to enhance their dissolution properties and reduce the fasted/fed state variability.

Powder bed packing and API content homogeneity of granules in single drop granule formation

Single drop granule formation on a static powder bed of pharmaceutical mixtures was studied to investigate the effects of hydrophobicity and primary particle size distribution on the powder bed packing structure and the content homogeneity of active pharmaceutical ingredient (API) in granules formed. The granule formation mechanisms, drop penetration time, granule morphology and internal structure have been previously investigated in a mixture of coarse microcrystalline cellulose (MCC) and fine acetaminophen (APAP). When the APAP amount increased (decreasing particle size and increasing hydrophobicity), drop penetration time increased, formation mechanisms transitioned from Spreading to Tunneling, the granules became smaller in size, and the internal porosity of the granules decreased (Gao et al., 2018). In the current study, single drop granulation on mixtures of MCC and APAP with different particle sizes were investigated for formation mechanisms and granule morphology. Additionally, the powder bed packing structure was characterized by X-ray micro-CT and the API content uniformity was measured by UV–vis spectrometry. It was found that in the mixture made from coarse MCC and fine APAP, the internal structure became heterogeneous and there were dense aggregate regions in both the powder bed and granules from 25% APAP proportion, where the transition from Spreading to Tunneling occurs. The content uniformities of granules from fine powder beds are much more compromised (indicating a discrepancy between the actual value and theoretical value) than those from coarse powder beds. This content discrepancy becomes much larger when the APAP proportion in the powder bed is higher (above 50%). This was previously observed by other researchers (Nguyen et al., 2010) and was attributed to the preferential wetting of the ingredients. It is believed that the primary particle size of the powder bed is more significant than the hydrophobicity in affecting the formation mechanism, granule internal structure, and content uniformity.

Fibrillated Cellulose via High Pressure Homogenization: Analysis and Application for Orodispersible Films.

Powdered cellulose (PC) and microcrystalline cellulose (MCC) are common excipients in pharmaceuticals. Recent investigations imply that particle size is the most critical parameter for the different performance in many processes. High-pressure homogenization (HPH) was used to reduce fiber size of both grades. The effect of the homogenization parameters on suspension viscosity, particle size, and mechanical properties of casted films was investigated. PC suspensions showed higher apparent viscosities and yield stresses under the same process conditions than MCC. SLS reduced shear viscosity and thixotropic behavior of both cellulose grades probably due to increased electrostatic repulsion. Homogenization reduced cellulose particle sizes, but re-agglomeration was too strong to analyze the particle size correctly. MCC films showed a tensile strength of up to 16.0MPa and PC films up to 4.1MPa. PC films disintegrated within 30s whereas MCC films did not. Mixtures of MCC and PC led to more stable films than PC alone, but these films did not disintegrate anymore. Diclofenac sodium was incorporated in therapeutic dose with drug load of 47% into orodispersible PC films. The content uniformity of these films fulfilled requirements of Ph.Eur and the films disintegrated in 12s. In summary, PC and MCC showed comparable results after HPH and most differences could be explained by the smaller particle size of MCC suspensions. These results confirm the hypothesis that mainly the fiber size during processing is responsible for the existing differences of MCC and PC in pharmaceutical process, e.g., wet-extrusion/spheronization.

Molecular partitioning in ternary solutions of cellulose

Neutron scattering measurements on the structure and dynamics of ternary solutions of microcrystalline cellulose (MC) in mixtures of an ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate and a polar organic solvent dimethylformamide (DMF) have shown that MC can be fully dissolved in solvent mixtures. Data also show the molecular partitioning of IL into coexisting states. The structure partitioning is manifested as IL adsorbed to cellulose molecules with additional IL self-assembled to form clusters in solution, while the dynamics partitioning shows dynamical heterogeneities of the IL with slow dynamics resembling neat IL and fast dynamics being coupled with the solvent. The composition dependence of the molecular partitioning results in a solubility gap in dilute cellulose solutions and a phase boundary criterion of the molar ratio of IL / MC ∼ 3 in more concentrated regimes. The two characteristics together define the main features of the dissolution phase diagram of ternary cellulose mixtures of MC / IL / DMF at the room temperature.

The Shielding Effect of Microcrystalline Cellulose on Drug Nanocrystal Particles During Compaction.

To elucidate the compaction behavior of drug nanocrystals based composite particles (NP) during tabletting, the compaction behavior of binary mixtures of microcrystalline cellulose (MCC) and nanocrystal particles was investigated. The force-displacement correlation of mixtures containing different ratios of MCC and micronized NP was studied in order to explain the nature on densification of NP during compaction, and the resultant compaction curves (pressure as function of in-die thickness) were systemically analyzed to elucidate the most important mechanisms of volume reduction for MCC and NP in different stages of compaction. The results showed that the close compaction of individual MCC was relatively quickly achieved, and the drug NP particles could slide into the intrinsic void spaces between MCC microparticles. This was the reason that the particles size of MCC used in this study was significantly larger compared to that of drug NP. This interstitial rearrangement phenomenon of NP occurred on a typical time scale and was strongly dependent on the speed of compaction. This migration behavior occurred on void spaces of MCC inter-particles might be identified as an elastic stress relaxation mechanism and be helpful to dissolution of NP. MCC can effectively shield the NP from significant aggregation during compaction process.

Multivariate calibration of energy-dispersive X-ray diffraction data for predicting the composition of pharmaceutical tablets in packaging

A system using energy-dispersive X-ray diffraction (EDXRD) has been developed and tested using multivariate calibration for the quantitative analysis of tablet-form mixtures of common pharmaceutical ingredients. A principal advantage of EDXRD over the more traditional and common angular dispersive X-ray diffraction technique (ADXRD) is the potential of EDXRD to analyse tablets within their packaging, due to the higher energy X-rays used.In the experiment, a series of caffeine, paracetamol and microcrystalline cellulose mixtures were prepared and pressed into tablets. EDXRD profiles were recorded on each sample and a principal component analysis (PCA) was carried out in both unpackaged and packaged scenarios. In both cases the first two principal components explained >98% of the between-sample variance. The PCA projected the sample profiles into two dimensional principal component space in close accordance to their ternary mixture design, demonstrating the discriminating potential of the EDXRD system.A partial least squares regression (PLSR) model was built with the samples and was validated using leave-one-out cross-validation. Low prediction errors of between 2% and 4% for both unpackaged and packaged tablets were obtained for all three chemical compounds. The prediction capability through packaging demonstrates a truly non-destructive method for quantifying tablet composition and demonstrates good potential for EDXRD to be applied in the field of counterfeit medicine screening and pharmaceutical quality control.

Development of a Novel Amorphous Agomelatine Formulation With Improved Storage Stability and Enhanced Bioavailability

The present work describes the development of a novel formulation of amorphous agomelatine (AGM) that exhibits enhanced in vitro dissolution rate and bioavailability, as well as improved storage stability. AGM was loaded on a mixture of microcrystalline cellulose with a high specific surface area excipient, namely colloidal silicon dioxide, employing a wet granulation method, and the resultant AGM granules were subsequently formulated into immediate release film-coated tablets. Modulated temperature differential scanning calorimetry, hot-state light microscopy, powder X-ray diffraction, attenuated total reflectance FTIR, and micro-Raman spectroscopy revealed that the active pharmaceutical ingredient existed primarily in the amorphous state within the prepared formulations, with some crystals of polymorph I also present. Accelerated stability studies for up to 6 months in alu-alu blisters showed good physicochemical stability during storage. Finally, in vitro dissolution studies and clinical trials in healthy human volunteers showed a remarkable increase in the in vitro dissolution rate and a ∼1.5-fold increase in bioavailability, respectively, compared to the marketed product.