Effect of Moisture on Powder Flow Properties of Theophylline

Application of the SeDeM system for the preparation of antiparasitic tablets from mesquite flour for use in sheep

The use of herbal medicine to treat various diseases is becoming increasingly important as an alternative therapy. Numerous plants have been traditionally used for different purposes, including antiparasitic in humans and animals. Diseases caused by gastrointestinal parasites in ruminants, especially by the nematode Haemonchus contortus, cause large economic losses to the producers, whether by complications of the diseases or the cost of treatment. The main way of handling nematodiasis is by administering anthelmintic drugs, but their excessive use has the disadvantage of causing drug resistance; therefore, an alternative is the use of herbal medicine for this purpose. Mesquite (Prosopis spp.) has been used in Mexico to treat gastrointestinal diseases attributed to helminths. The present study aimed to characterize the rheological properties of mesquite flour using the SeDeM Expert System to determine its suitability for tablet production by direct compression. Direct compression technology facilitates the tableting process by reducing manufacturing costs. The results of the present study indicate that mesquite flour can be processed by direct compression. The latter could allow the manufacturing of economic tablets to treat infections by H. contortus in ruminants.

Modulation of the Capillary Force Profile at the Solid-Solid Interface through Topographical Modifications

Modulations of interfacial adhesion at solid-solid contacts are desired in many multidisciplinary applications. This study aims at the creation of reproducible solid-solid interfaces with significantly mitigated capillary adhesion through physical modifications. First, a continuum boundary element-based mathematical model to predict capillary forces at solid-solid contacts was developed and validated. Next, the model was utilized to simulate the capillary adhesion between a glass substrate with hypothetical surface topographies, in the form of nanopillars and nanowells, and silica particles of various sizes at varied humidity conditions. This study revealed that the nanopillar surface topography was much more effective than the nanowell in suppressing the capillary condensation and could lower the capillary forces by more than one order of magnitude for the micrometer-scale and nanoscale particulates. This study suggested that topographical tuning at the solid-solid interface can significantly reduce interfacial adhesion and promote the dust-resistance characteristic of a substrate. Finally, this simulation study can guide the fabrication of solid surfaces with reproducible topography and optimized geometrical parameters to yield an extremely reduced interfacial capillary adhesion.

Co-Crystallization Approach to Enhance the Stability of Moisture-Sensitive Drugs

Stability is an essential quality attribute of any pharmaceutical formulation. Poor stability can change the color and physical appearance of a drug, directly impacting the patient's perception. Unstable drug products may also face loss of active pharmaceutical ingredients (APIs) and degradation, making the medicine ineffective and toxic. Moisture content is known to be the leading cause of the degradation of nearly 50% of medicinal products, leading to impurities in solid dose formulations. The polarity of the atoms in an API and the surface chemistry of API particles majorly influence the affinity towards water molecules. Moisture induces chemical reactions, including free water that has also been identified as an important factor in determining drug product stability. Among the various approaches, crystal engineering and specifically co-crystals, have a proven ability to increase the stability of moisture-sensitive APIs. Other approaches, such as changing the salt form, can lead to solubility issues, thus making the co-crystal approach more suited to enhancing hygroscopic stability. There are many reported studies where co-crystals have exhibited reduced hygroscopicity compared to pure API, thereby improving the product's stability. In this review, the authors focus on recent updates and trends in these studies related to improving the hygroscopic stability of compounds, discuss the reasons behind the enhanced stability, and briefly discuss the screening of co-formers for moisture-sensitive drugs.

Oxidative stability and sensory evaluation of sodium caseinate-based yak butter powder

Yak butter's high unsaturated fatty acid level predisposes it to oxidation, hence must be converted into more stable forms like powder. This study aimed to spray dry yak butter using 10% yak butter and four sodium caseinate (NaCas) formulations: sample A: 100% NaCas; sample B: 50% NaCas, 50% lactose; sample C: 75% NaCas, 25% lactose; and sample D: 25% NaCas, 75% maltodextrin. The powders were vacuum and hermetically sealed, and evaluated for oxidative stability, physical and sensory properties during storage at 65 ℃ for 30 days. The results showed that samples B and D had similar and most favorable physical properties (such as, moisture, water activity, particle size, bulk density re-dispersion time, and encapsulation efficiency); though sample B, together with sample C, browned the most during storage. The majority of the sensory panelists preferred samples B and D; observed high caking in samples C and B; and the least whiteness loss and caking in samples D and A but high off-flavors in samples A and C. After storage, peroxide and thiobarbituric acid values of powder samples ranged from 34.98 to 69.54 meqO2/kg and 1.85-9.43 mg MD/kg, respectively, in the decreasing order of A, C, B, and D. Sample D, followed by B, showed the highest radical scavenging activity. Therefore, for optimum yak butter powder physical properties and oxidative stability, 50%:50%, NaCas: lactose, and 25%:75%, NaCas: maltodextrin formulations should be used. This study provides essential knowledge for butter powder processors.

Quantifying the Soil Arthropod Diversity in Urban Forest in Dera Ghazi Khan

Arthropods can be either large or too small to be seen from the microscope. Their legs are jointed and perform a specific function in the soil. Several arthropods have been identified to date. Therefore, it is essential to identify them in a different type of soil. An experiment to quantify the soil arthropods in the urban forests of D.G. Khan was conducted at the Zoology lab of Ghazi University on four tree plants, i.e., neem (Azadirachta indica), mango (Mangifera indica), guava (Psidium guajava), and phalsa (Grewia asiatica). Soil samples were taken from different areas and on different months. The diversity of arthropods was analyzed through the Shannon index. The results were all significant. The total number of arthropods found in the experiment was 5151, with the following distributions: millipedes were 132 in neem, 133 in guava, 113 in mango, and 121 in phalsa; centipedes were 136 in neem, 142 in guava, 118 in mango, and 132 in phalsa; springtails were 138 in neem, 130 in guava, 120 in mango, and 134 in phalsa. There were a total of 12 different species of arthropods found. Neem (Azadirachta indica) have mites, centipede, and ants; guava (Psidium guajava) have centipedes and ants. Mango (Mangifera indica) have millipedes, centipedes, mites, springtail, and ants, and phalsa (Grewia asiatica) have mites, ants, and centipedes. The study reveals that millipedes, centipedes, springtails, and ants were found abundantly in the urban forest area of D.G. Khan, resulting in increased organic matter decomposition and appropriate distribution of nutrients through the soil having beneficial effects on the terrestrial ecosystem.

Formation and Physico-Chemical Evaluation of Nifedipine-hydroxypropyl-β-cyclodextrin and Nifedipine-methyl-β-cyclodextrin: The Development of Orodispersible Tablets

The novelty in this study is the development of new orodispersible tablets containing nifedipine (NIF) as the active ingredient. Initially, the formation of inclusion complexes between nifedipine and two derivatives of beta-cyclodextrin, namely, hydroxypropyl-β-cyclodextrin (HP-β-CD) and methyl-β-cyclodextrin (Me-β-CD), was established. Inclusion complexes of nifedipine were prepared by different procedures: kneading, coprecipitation and lyophilization methods, using a 1:1 molar ratio among the drug and cyclodextrin compounds. A physical mixture was also developed for comparison, with the same molar ratio. The physicochemical and structural properties of these obtained complexes were subsequently analysed using Fourier-transform infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry and X-ray diffraction techniques. The lyophilization method of preparation leads to obtaining the complete inclusion of nifedipine in the used cyclodextrin cavity, for both the derivative cyclodextrins. After that, preformulation studies and manufacturing of orodispersible tablets containing NIF-HP-β-CD and NIF-Me-β-CD, respectively, inclusion complexes were advanced. The obtained findings show that only F3 (which contains NIF-HP-β-CD) and F6 (which contains NIF-Me-β-CD) have a suitable flowability for the direct compression materials.

Tailoring functional spray-dried powder platform for efficient donepezil nose-to-brain delivery

Shortcomings of oral donepezil administration in the treatment of Alzheimer's disease have paved the way for ongoing investigations towards more efficient and safe donepezil nose-to-brain delivery. Herein we present the development of advantageous powder platform for donepezil nose-to-brain delivery, coupling careful design of chitosan and mannitol-based carrier matrix with spray-drying technology advantages and early consideration of adequate nasal administration mode, employing QbD approach. Unprecedentedly, ultrasonic nozzle was used to atomise the drying feed in response to size-related requirements for nasal aerosol particles. The optimised spray-drying process resulted in free-flowable dry powder with a great majority of particles larger than 10 µm, ensuring localised nasal deposition upon aerosolization, as evidenced by using 3D-printed nasal cavity model. QbD approach coupling formulation, process and administration parameters enabled optimisation of drug deposition profile reaching tremendously high 65.5 % of the applied dose deposited in the olfactory region. The leading formulation exhibited favourable swelling, mucoadhesion, drug release and permeation-enhancing properties, suiting the needs for efficient brain-targeted delivery. Results of in vitro biocompatibility and physico-chemical stability studies confirmed the leading formulation potential for safe and efficient donepezil nose-to-brain delivery. The obtained results encourage extending the study to an appropriate in vivo model needed for the final proof-of-concept.

Impact of Amylose-Amylopectin Ratio of Starches on the Mechanical Strength and Stability of Acetylsalicylic Acid Tablets

The two main components of starch - amylose and amylopectin, are responsible for its interaction with moisture. This study investigated how moisture sorption properties of the starches with different amylose-amylopectin ratio impacted tablet properties including drug stability. The starch samples were equilibrated to 33, 53, and 75% relative humidity (RH) and then assessed for tabletability, compactibility, and yield pressure. Effect of humidity on viscoelastic recovery was also evaluated. Tabletability and compactibility of high-amylose starch were better than that of high-amylopectin starch at 33 and 53% RH. However, at 75% RH, the reverse was observed. In terms of yield pressure, high-amylose starch had lower yield pressure than high-amylopectin starch. High-amylose starch tablets also exhibited lower extent of viscoelastic recovery than high-amylopectin starch tablets. The variations in the tableting properties were found to be related to relative locality of the sorbed moisture. Degradation of acetylsalicylic acid in high-amylose starch tablets at 75% RH, 40°C was less than the tablets with high-amylopectin starch. This observation could be attributed to the greater amount of water molecules binding sites in high-amylose starch. Furthermore, most of the sorbed moisture of high-amylose starch was internally absorbed moisture, therefore limiting the availability of diffusible sorbed moisture for degradation reaction. Findings from this study could provide better insights on the influence of amylose-amylopectin ratio on tableting properties and stability of moisture-sensitive drugs. This is of particular importance as starch is a common excipient in solid dosage forms.

DDSolver Software Application for Quantitative Analysis of In Vitro Drug Release Behavior of the Gastroretentive Floating Tablets Combined with Radiological Study in Rabbits

Background:

Gastroretentive drug delivery systems (GRDDSs) are designed to release the drug in the stomach over a prolonged time; thus, they can reduce drug dosing frequency and dose size and improve patient compliance. GRDDSs are also highly effective in enhancing the bioavailability of the drug that exhibits window absorption in specific segments of the gastrointestinal (GI) tract. Famotidine (FMT), an H2 receptor antagonist, is an example of these drugs. FMT is a slightly water-soluble drug but well soluble in an acidic medium. This research aims to formulate FMT gastro-retentive floating tablets (FMT-GRFTs) to improve the bioavailability and therapeutic activity of the drug and increase patients' adherence to treatment. In addition, the in vitro release behavior of the prepared FMT-GRFTs was quantitatively analyzed using the DDSolver software to assist in selecting the successful formulation that was then evaluated in vivo.

Methods:

The direct compression technique prepared numerous tablet formulations and was subjected to the pre-and post-compression evaluation. Data of FMT dissolution in the simulated gastric medium was analyzed by various kinetic models built in the DDSolver program. In addition, the simulated pharmacokinetics (AUC, MDT, and MRT), R2 adjusted, AIC, MSC, correlation of the residuals, and similarity factor (f2) were also generated.

Results:

The results revealed that FMT release from the candidate formula (FH3) fitted to the first-order kinetic model, with a high value of R2 adjusted and MSC and a low AIC. The release behavior exhibited the Fickian diffusion mechanism. The similarity factor showed no significant difference (p < 0.05) of the test sample compared to the reference product. Nevertheless, the simulated pharmacokinetic parameter, AUC, proved a two-fold enhancement in FMT bioavailability, with a significant increment in the MDT and MRT compared with the reference product. The FT-IR spectroscopy analysis indicated the absence of drug-excipients/polymer interaction. The in vivo X-ray studies on rabbits confirmed that the floating tablets showed nearly eight hours of gastric residence.

Conclusion:

DDSolver software was helpful in deciding the optimized formulation of FMT floating tablets. The radiological examination in rabbits for gastric retention was consistent with the release data analysis in vitro.

Experimental and Numerical Study of the Discharge Performance of Particle-Laden Turbulent Flow

In the marine fire suppression system, continuous delivery of dry chemical powder to the fire source with long powder discharge range and high dispersion concentration is essential. The work is devoted to experimental and numerical studies of the flow characteristics of the dry chemical powder jet from a horizontal injector with a wide range of Stokes numbers between 6 to 30 and Reynolds numbers between 4792 to 23,960 by considering the effect of gravitational acceleration. A CFD-based Eulerian–Eulerian multiphase model combined with Standard k-ω turbulence model was used to predict flow characteristics of particle-laden jet using dimensionless numbers, including the solid volume fraction, the normalized velocity magnitude, and the turbulent viscosity ratio. Experimental studies have been carried out for three different inflow velocities (2.06, 2.45, and 2.81 m/s). The results indicate that the particle density plays a significant role in the dispersion of the particles in the radial and axial directions. The transition from U-shaped to V-shaped solid dispersion structure on the ground can be captured with the increase of particle density. Moreover, the higher level turbulence intensity enhances the solid dispersion concentration. Finally, it was found that the Portland cement powder exhibits better discharge performance in terms of solid discharge range and dispersion concentration in comparison with other dry powders. These results have implications in the design of powder-based fire suppression system. Further studies should aim to the in-depth research on the fire extinguishing mechanism of the Portland cement powder, especially the fire suppression effectiveness and thermal decomposition process.

D-Sorbitol Physical Properties Effects on Filaments Used by 3D Printing Process for Personalized Medicine

Fused filament fabrication (FFF) is a process used to manufacture oral forms adapted to the needs of patients. Polyethylene oxide (PEO) filaments were produced by hot melt extrusion (HME) to obtain a filament suitable for the production of amiodarone hydrochloride oral forms by FFF 3D printing. In order to produce personalized oral forms adapted to the patient characteristics, filaments used by FFF must be controlled in terms of mass homogeneity along filament. This work highlights the relation between filament mass homogeneity and its diameter. This is why the impact of filler excipients physical properties was studied. It has been showed that the particle’s size distribution of the filler can modify the filament diameter variability which has had an impact on the mass of oral forms produced by FFF. Through this work it was shown that D-Sorbitol from Carlo Erba allows to obtain a diameter variability of less than 2% due to its unique particle’s size distribution. Using the filament produced by HME and an innovating calibration method based on the filament length, it has been possible to carry out three dosages of 125 mg, 750 mg and 1000 mg by 3D printing with acceptable mass uniformity.

Effect of colloidal silicon dioxide and moisture on powder flow properties: Predicting in-process performance using image-based analysis

The effect of colloidal silicon dioxide (CSD) on powder flow properties of poor-flowing excipient lactose 200 M was investigated. Binary mixtures of different ratios of CSD as glidant were examined using a modern image-based flow measuring technique. Special attention was placed to subtle variations in powder flow from small changes in glidant concentration (0.025% w/w). Understanding the modes of interaction of particles and their effects on flowability using the method predicted the die filling performance during tablet manufacture. In addition, the importance of moisture content on powder flow properties was empirically underlined. A more efficient range of CSD was detected from 0.10 to 0.50% w/w in most of the tested conditions, which revealed a significant improvement in powder flow performance compared to higher amounts typically handled in the pharmaceutical industry.

Investigation into powder tribo-charging of pharmaceuticals. Part II: Sensitivity to relative humidity

Environmental conditions can have a profound impact on the bulk behaviour of pharmaceutical powders, including their tribo-charging tendency. Typically, high relative humidity (RH) has been associated to a reduction in the electrostatic charge of the material. However, the occurrence of charge mitigation seems to be related to the quantity of water molecules at the powder surface, which depends on intrinsic material attributes (i.e., water sorption propensity), and external factors (i.e., RH level). In the present study, pharmaceutical powders (i.e., microcrystalline cellulose, D-mannitol, paracetamol and magnesium stearate) were conditioned at three levels of RH, relevant for pharmaceutical operations, and their bulk behaviour, including charging propensity, was analyzed. Depending on the material type, powders sorbed water from the humid atmosphere to different extents, resulting in different charging behaviours. Overall, the charge density of the materials was found to decrease after a certain RH or monotonically decrease with an increase of RH, except for D-mannitol. For this material, a contrasting trend of increase in charging was observed with an increase in RH. Moreover, the powders showed a distinct tribo-charging sensitivity to RH, with paracetamol being the most affected. These findings suggest that a careful consideration on solid material-moisture interactions is needed when using RH as strategy to minimize electrostatic effects in powder processing.

An Investigation into the Influence of Process Parameters and Formulation Variables on Compaction Properties of Liquisolid Systems

Liquisolid technology, as a promising approach for bioavailability enhancement, has received increasing attention in recent years. However, literature reports addressing the challenges for its industrial application, particularly those related to compaction behavior of liquisolid systems, are scarce. The aim of this study was to investigate the influence of process parameters and formulation variables on the flowability, wetting, and compaction properties of the liquisolid systems prepared in a fluid bed processor. The experiments with microcrystalline cellulose, as a carrier, were performed according to 2³ full factorial design. The effects of liquid content, spray air pressure, and liquid feed rate on the properties of liquisolid systems were investigated. Liquisolid admixtures with microcrystalline cellulose were compared with those prepared with novel carriers, Fujicalin^® and Neusilin^® US2. "Out-die" Heckel, modified Walker, and Kuentz-Leuenberger models were used to analyze the compressibility of liquisolid admixtures. The results obtained showed that an increase in liquid content (in the range of 10 to 15%) led to a decrease in flowability of liquisolid admixtures with microcrystalline cellulose, as well as more pronounced influence of spraying conditions. On the other hand, higher liquid content led to higher compressibility. Fujicalin^® and Neusilin^® US2 liquisolid admixtures were found to have superior flowability and compressibility in comparison with those with microcrystalline cellulose, despite the considerably higher liquid load (50-55% liquid content in Neusilin^® US2 compacts). Acceptable compactibility of the investigated liquisolid systems was observed. The fluid bed processor was shown to be suitable equipment for production of liquisolid systems, but with careful adjustment of process parameters.

Conversion of Lignocellulosic Corn Agro-Waste into Cellulose Derivative and Its Potential Application as Pharmaceutical Excipient

Lignocellulosic biomass is widely grown in many agricultural-based countries. These are typically incinerated or discarded in open spaces, which further may cause severe health and environmental problems. Hence, the proper utilization and conversion of different parts of lignocellulosic biomasses (e.g., corn wastes derived leave, cob, stalk, and husk) into value-added materials could be a promising way of protecting both health and environments. In addition, they have high-potential for myriads applications (e.g., pharmaceuticals, cosmetics, textiles, and so on). In this context, herein, we isolated holocellulose (a mixture of alpha α, beta β, and gamma γ cellulose) from corn waste, and then it was converted into carboxymethyl cellulose (CMC). Subsequently, the prepared CMC was evaluated successfully to be used as a pharmaceutical excipient. Different characterization tools were employed for structural, morphological, and thermal properties of the extracted holocellulose and synthesized CMC. Results showed that the highest yield of CMC was obtained 187.5% along with the highest degree of substitution (DS i.e., 1.83) in a single stage (i.e., size reduction technique) with the lowest particle size of holocellulose (100 µm). This happened due to the use of a single stage instead of multiple stages. Finally, extracted CMC was successfully used as a pharmaceutical excipient with promising results compared to commercially available pharmaceutical-grade CMC.

Lactose monohydrate flow characterization using shear cell method

The flow properties of pharmaceutical powders have a great importance in the manufacturing of solid dosage forms. In order to ensure the performance in the production line this parameter must be determined. There are several methods described in European Pharmacopeia that are used to measure these properties. Some of them were used in this study and the results obtained from conventional methods (Conv) and shear cell using the powder flow tester (PFT) showed differences that were more evident in fractions with smaller particle size (F < 63) and for bulk powder (F_Total). The various powder behaviors showed to be related with the size of the particles. An increase of the ff_c (Flow Index) was observed with the increase of the particle size. It was also found for the different fractions that the ff_c always increases with increasing major principal consolidation stress (σ₁). This study shown to be predictive because it also allowed the behavior profiles of other LactMN fractions to be known by interpolation of the median size (Dv50) or σ₁ values ranged between the studied intervals. Furthermore, it was also observed that ff_c of the F_Total was similar to the F < 63, showing the same behavior under σ₁. The occurrence of caking was not observed.

Swellable polymeric particles for the local delivery of budesonide in oral mucositis

Topical drug delivery in the oral mucosa has its set of challenges due to the unique anatomical and physiological features of the oral cavity. As such, the outcomes of local pharmacological treatments in oral disorders can fail due to unsuccessfully drug delivery. Oral mucositis, a severe inflammatory and ulcerative side effect of oncological treatments, is one of such diseases. Although the damaged tissue is within reach, no approved topical drug treatment is available. Several strategies based on its physiopathology have been implemented and clinically used. Even so, results tend to lack or be insufficient to improve patient's quality of life. The use of corticosteroids has been employed in such strategies due to their strong anti-inflammatory action. Typically, these are administrated in simple liquid formulations, where the drug is dispersed or solubilized, lacking the ability to maintain local concentration. In this work, we propose the development of a biocompatible delivery system with boosted abilities of retention and control release of budesonide, a corticosteroid with an elevated ratio of topical anti-inflammatory to systemic action. Through spray-drying, polymeric particles of Chitosan and Eudragit® E PO were produced and characterized for the vectorization of this drug.

Effects of Particle Surface Roughness on In-Die Flow and Tableting Behavior of Lactose

Particle rearrangement takes place during the initial phase of tablet compaction. In this study, rough lactose particles were prepared by roller compaction, and their surface roughness modified by partial surface dissolution using a fluidized bed processor. Flow characteristics of the particles were determined using various flow methods, and their compaction characteristics studied using a compaction simulator with punches of different geometry and compaction pressure. Rougher particles demonstrated poorer compressibility and powder flow due to the higher interparticulate frictional forces required for particle movement. Rearrangement energy during tablet compaction was found to be correlated with compressibility (R² = 0.92) and increased with surface roughness of the particles. Particle rearrangement was found to be dependent on interparticulate frictional forces, which could be measured using FT4 powder rheometer variable flow rate test and compressibility test. Plastic energy decreased as a result of the increased rearrangement energy requirements. Decrease in tensile strength as a result of decrease in plastic energy was not significantly different. Roller-compacted lactose particles produced tablets of higher tensile strength than crystalline lactose because of prefragmentation of the crystalline structure during roller compaction.

The Proportion of Fermented Milk in Dehydrated Fermented Milk⁻Parboiled Wheat Composites Significantly Affects Their Composition, Pasting Behaviour, and Flow Properties on Reconstitution

Dairy and cereal are frequently combined to create composite foods with enhanced nutritional benefits. Dehydrated fermented milk–wheat composites (FMWC) were prepared by blending fermented milk (FM) and parboiled wheat (W), incubating at 35 °C for 24 h, drying at 46 °C for 48 h, and milling to 1 mm. Increasing the weight ratio of FM to W from 1.5 to 4.0 resulted in reductions in total solids (from 96 to 92%) and starch (from 52 to 39%), and increases in protein (15.2–18.9%), fat (3.7–5.9%), lactose (6.4–11.4%), and lactic acid (2.7–4.2%). FMWC need to be reconstituted prior to consumption. The water-holding capacity, pasting viscosity, and setback viscosity of the reconstituted FMWC (16.7% total solids) decreased with the ratio of FM to W. The reconstituted FMWC exhibited pseudoplastic flow behaviour on shearing from 18 to 120 s⁻¹. Increasing the FM:W ratio coincided with a lower yield stress, consistency index, and viscosity at 120 s⁻¹. The results demonstrate the critical impact of the FM:W ratio on the composition, pasting behavior, and consistency of the reconstituted FMWC. The difference in consistency associated with varying the FM:W ratio is likely to impact on satiety and nutrient value of the FMWCs.

Powder Flow Testing: Judicious Choice of Test Methods

Flow property of pharmaceutical powders can be assessed by various flow testers and test methods. In this study, eight commercially available lactose grades were sourced and tested for angles of repose, tapping studies, shear cell measurements, stirred powder rheometry, and avalanching powder measurements. The relationships between various flow parameters and particle size were analyzed. Deviations from the general trend could be attributed to either the insensitivity of the test or differences in particle shape. The basic flowability energy of the powder rheometer was unable to reconcile the effects of shape and particle size on powder flowability. Avalanche time of the revolving drum powder analyzer and angle of repose exhibited good correlation with each other (r = 0.92) but experienced poor resolution for samples of smaller particle sizes due to powder cohesiveness and the propensity for agglomerative flow. Flow test parameters could be categorized into three broad types, based on their relationship with particle size: (i) linear relationship, (ii) test parameter more sensitive to smaller sized particles, and (iii) test parameter more sensitive to larger sized particles. Choice of test parameters used to represent powder flow should be dependent on the sensitivity of the selected flow test methods to the sample types.

The Effects of Relative Humidity on the Flowability and Dispersion Performance of Lactose Mixtures

The flowability and dispersion behavior are two important physicochemical properties of pharmaceutical formulations for dry powder inhalers (DPIs). They are usually affected by the environmental conditions, such as temperature and relative humidity (RH). However, very few studies have been focused on the relationship between the two properties and their dependence on RH during storage. In this research, model pharmaceutical formulations were prepared using mixtures of coarse and fine lactose. The fractions of fines in the mixtures were 0%, 5%, 10%, and 20%, respectively. These blends were stored at four different RH levels, 0%, 30%, 58%, and 85%, for 48 h. The FT4 Powder Rheometer was used to evaluate the powder flowability, and the Malvern Spraytec^® laser diffraction system was employed to assess the powder dispersion performance. The results indicated that both the flow and dispersion properties of lactose blends deteriorate after being stored at 85% RH, but improved after being conditioned at 58% RH. The fine particle fractions (FPFs) of the blends with 5% and 10% fine fractions and the as-received coarse lactose decreased when they were conditioned at 30% RH. For the blend with 20% fine fraction, a high RH during storage (i.e., 85% RH) affected the dispersion property, but had a limited influence on its flowability, while, for the coarse lactose powder, the different RH conditions affected its flowability, but not the dispersion results. A strong correlation between the powder flowability and its dispersion performance was found.

In-line monitoring of compaction properties on a rotary tablet press during tablet manufacturing of hot-melt extruded amorphous solid dispersions

As the number of applications for polymers in pharmaceutical development is increasing, there is need for fundamental understanding on how such compounds behave during tableting. This research is focussed on the tableting behaviour of amorphous polymers, their solid dispersions and the impact of hot-melt extrusion on the compaction properties of these materials. Soluplus, Kollidon VA 64 and Eudragit EPO were selected as amorphous polymers since these are widely studied carriers for solid dispersions, while Celecoxib was chosen as BCS class II model drug. Neat polymers and physical mixtures (up to 35% drug load) were processed by hot-melt extrusion (HME), milled and sieved to obtain powders with comparable particle sizes as the neat polymer. A novel approach was used for in-line analysis of the compaction properties on a rotary tablet press (Modul P, GEA) using complementary sensors and software (CDAAS, GEA). By combining 'in-die' and 'out-of-die' techniques, it was possible to investigate in a comprehensive way the impact of HME on the tableting behaviour of amorphous polymers and their formulations. The formation of stable glassy solutions altered the formulations towards more fragmentary behaviour under compression which was beneficial for the tabletability. Principal component analysis (PCA) was applied to summarize the behaviour during compaction of the formulations, enabling the selection of Soluplus and Kollidon VA 64 as the most favourable polymers for compaction of glassy solutions.

Effect of Percent Relative Humidity, Moisture Content, and Compression Force on Light-Induced Fluorescence (LIF) Response as a Process Analytical Tool

The effect of percent relative humidity (16-84% RH), moisture content (4.2-6.5% w/w MC), and compression force (4.9-44.1 kN CF) on the light-induced fluorescence (LIF) response of 10% w/w active pharmaceutical ingredient (API) compacts is reported. The fluorescent response was evaluated using two separate central composite designs of experiments. The effect of % RH and CF on the LIF signal was highly significant with an adjusted R (2)  = 0.9436 and p < 0.0001. Percent relative humidity (p = 0.0022), CF (p < 0.0001), and % RH(2) (p = 0.0237) were statistically significant factors affecting the LIF response. The effects of MC and CF on LIF response were also statistically significant with a p value <0.0001 and adjusted R (2) value of 0.9874. The LIF response was highly impacted by MC (p < 0.0001), CF (p < 0.0001), and MC(2) (p = 0022). At 10% w/w API, increased % RH, MC, and CF led to a nonlinear decrease in LIF response. The derived quadratic model equations explained more than 94% of the data. Awareness of these effects on LIF response is critical when implementing LIF as a process analytical tool.

The effect of moisture on the flowability of pharmaceutical excipients

The effect of moisture content on flowability of six pharmaceutical powders (microcrystalline cellulose (MCC), hydroxypropyl methylcellulose (HPMC), carboxymethyl cellulose (CMC), polyvinylpyrrolidone (PVP), corn starch, and potato starch) was investigated. Powder flowability was measured using established static techniques and emerging dynamic avalanche behavior measurements. Static techniques did not provide enough resolution to clearly identify changes in flowability due to increasing powder moisture content. Avalanche time and its standard deviation showed that flowability of MCC, CMC, PVP, and potato starch decreased after a critical moisture content, flowability of corn starch increased and flowability did not significantly change for HPMC. The moisture decreased flowability by forming stronger interparticle liquid bridges and increased flowability by acting as a lubricant. The dynamic density of the celluloses and PVP decreased linearly with increasing moisture content as the particles swelled with water. The starches also swelled and decreased in dynamic density, but only after a moisture content corresponding to monolayer coverage of water around the particles was reached. As flowability and dynamic density change with moisture content, to ensure consistent production of high-quality tablets, the moisture content of the powders must be measured and controlled.

Formulation development and rheological studies of palatable cefetamet pivoxil hydrochloride dry powder suspension

BACKGROUND AND THE PURPOSE OF THE STUDY

Because of its intense bitter taste and susceptibility to moisture Cefetamet Pivoxil (CPH) is presently available only in the form of tablet. The aim of this study was to develop taste masked CPH dry powder suspension.

METHODS

METHODS EMPLOYED FOR FORMULATIONS WERE: a) Film coating of CPH using Eudragit E100 and subsequent adsorption on different carriers such as spray-dried lactose, sodium starch glycolate and spray-dried mannitol and b) Complexation of CPH with three different ion exchange resins indion 234 amberlite IRP64 and amberlite IRP69.

RESULTS

Taste viz evaluation as recognized by volunteers revealed that coating with Eudragit E100 and subsequent adsorption on different carriers do not mask the bitter taste of the drug. Suspensions prepared using amberlite IRP64 and amberlite IRP69 were extremely palatable with no bitter after taste. They showed pseudoplastic flow behavior and were too viscous even after shearing for sufficient duration of time and exhibited poor pourability. The suspension made with indion 234 was palatable with slight or no bitter after taste. It demonstrated plastic flow with negligible thixotropy. It had moderate viscosity at rest and could be poured after a reasonable amount of shaking. CPH dry powder suspensions were very unstable under different conditions except under refrigeration. A 5% degradation of drug was occurred in reconstituted suspension in 4 days period when stored at room temperature.

CONCLUSION

Dry powder suspension prepared with indion 234 having 5% overages was stable even after 4th day of reconstitution and palatable with slight or no bitter after taste.