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Design of systems for oral controlled release of drug could take advantages from the knowledge of which phenomena take place. In this work matrices obtained by powders compression (50:50, hydroxypropyl methylcellulose, a swelling hydrogel, and theophylline, a model drug) were immersed in water at 37°C, allowing the water uptake and the drug release by lateral surface, confining the cylindrical matrices between glass slides. The tablets, after given immersion times, were withdrawn, cut in several annuli, and subsequently analyzed for the drug and the water concentration radial profiles. The data confirmed the pseudo-diffusive nature of the process, allowing to give a deep insight into the drug release process from swellable hydrogel matrices. In particular, it was confirmed the presence of nonhomogeneous gel layer, rich in water and poor in drug, with a profile of drug concentration which agrees well with a pseudo-diffusion phenomenon. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:4100–4110, 2009 [ABSTRACT FROM AUTHOR]

Abstract: The water swellable hydrogels are commonly used in the production of solid pharmaceutical dosage systems for oral administration (matrices). Their use allows to obtain the controlled drug release. The key role is played by the transport phenomena which take place: water up-take, gel swelling and erosion, increase in diffusivity due to hydration. Thus, knowledge of these phenomena is fundamental in designing and realizing the pharmaceutical systems. In this work, tablets made of pure hydrogel, HydroxyPropyl-MethylCellulose (HPMC), were produced and immersed in a thermostatic bath filled with stirred distilled water (37°C). The water up-take was allowed only by radial direction (from the lateral surface) by confining the tablet between two glass slides. Two distinct methods, an optical technique already described in a previous work, and a gravimetric procedure described here, were applied to measure the water concentration profiles along the radial direction in the tablets. The data obtained were used both to clarify the nature of the transport phenomena involved, and to perform a better tuning of a mathematical model previously proposed. [Copyright &y& Elsevier]

Abstract: Drying constitutes a critical unit operation in the manufacturing of pharmaceutical powders and their associated products. In this work, the drying processes of cellulose derivative (hydroxypropyl methyl cellulose, HPMC) granules were investigated. Granules of HPMC powders were produced by a wet granulation process using a hydro-alcoholic solution as binder phase, then they were dried with different drying methods based on traditional (by convective heating) and innovative (by microwave heating) techniques. To compare drying kinetics, experimental data were fitted by Lewis equation obtaining drying coefficients, and time/temperature process parameters were investigated. Microwave assisted drying showed reduced process times and, under some conditions, it allowed no drastic process temperatures. Since granular solids have a great relevance in pharmaceutical solid dosage form preparations, novel methods of drying with better performances appeared an issue of great interest for industry. [Copyright &y& Elsevier]

Abstract: This paper presents a tandem technique, based on the combination of prilling and microwave (MW) assisted treatments, to produce biodegradable alginate carriers of piroxicam with different drug controlled release behaviours. Results showed that alginate/piroxicam beads demonstrated high encapsulation efficiency and very narrow dimensional distribution. Beads dried by MW retained shape and size distribution of the hydrated particles while drying rate was strongly increased compared to convective drying processes. Moreover, different MW irradiation regimes promoted interactions between the drug and alginate matrix, affected drug polymorphism as well as inner and surface matrix structure leading to different piroxicam release profiles. High level MW irradiation led to beads with highly porous and swellable matrix able to release piroxicam in few minutes in the intestine while convective drying produced gastro-resistant beads that exhibit sustained piroxicam release (total release in 5.5h) in intestinal environment. On these results the tandem technique prilling/MW irradiation appears to be promising to obtain alginate carrier with tailored NSAIDs release depending on drug characteristics and MW irradiation. [Copyright &y& Elsevier]

Abstract Wet granulation is a size-enlargement process applied in many industrial fields, such as pharmaceutical, nutraceutical, zootecnichal, to improve flowability and compressibility properties of powders. In this work analysis of the particle size distribution (PSD) of granules was performed to understand the phenomena involved during the granulation process and to optimize the operating conditions. Hydroxypropyl methylcellulose (HPMC) granules were produced spraying distilled water as liquid binder on powders in a low-shear granulator. The experimental campaign was planned using the full factorial design statistical technique varying two factors (impeller rotation speed and binder flow rate), each at three intensities. PSDs of HPMC granules at different granulation times were obtained by an ad hoc dynamic image analysis device based on the free falling particle scheme. PSD measurements showed that wet granules size depends on the simultaneous presence of nucleation, agglomeration and breakage phenomena. The process parameters optimization was carried out using response surface methodology (RSM) and using the granulation yield (% w/w of wet granules within the size range 2000–10,000 μm) as the main variable of interest. Graphical abstract Unlabelled Image Highlights • Dynamic Image Analysis is a useful tool to monitor the time evolution of the PSD. • The PSD evolution allows to study the phenomenology of a wet granulation process. • Agglomeration, breakage and nucleation are present in the HPMCwet-granulation. • PSD and response surface methodology allow to optimize the process parameters. [ABSTRACT FROM AUTHOR]

Due to its versatile properties, hydroxypropyl methylcellulose (HPMC) is largely used in many applications and deeply studied in the various fields such as pharmaceuticals, biomaterials, agriculture, food, water purification. In this work, vitamin B12 loaded HPMC granules were produced to investigate their potential application as nutraceutical products. To this aim the impact of vitamin load on physico-chemical, mechanical and release properties of granules, achieved by wet granulation process, was investigated. In particular, three different loads of B12 (1%, 2.3% and 5% w/w) were assayed. Unloaded granules (used as control) and loaded granules were dried, sieved, and then the suitable fraction for practical uses, 0.45–2 mm in size, was fully characterized. Results showed that the vitamin incorporation of 5% reduced the granulation performance in the range size of 0.45–2 mm and led granules with higher porosity, more rigid and less elastic structures compared to unloaded granules and those loaded at 1% and 2.3% of B12. Vitamin release kinetics of fresh and aged granules were roughly found the same trends for all the prepared lots; however, the vitamin B12 was released more slowly when added with a load at 1% w/w, suggesting a better incorporation. [ABSTRACT FROM AUTHOR]

Highlights: [•] A fast method to assay the water concentration in HPMC matrices was proposed. [•] The method is based on penetration force derivative with distance measurements. [•] The method was tuned by comparison with the measurements in uniform hydrogels. [•] The novel tool is of interest for pharmaceutical and food applications. [ABSTRACT FROM AUTHOR]

Abstract: In this work, a fast and accurate method to evaluate the water content in a cellulose derivative-based matrix subjected to controlled hydration was proposed and tuned. The method is based on the evaluation of the work of penetration required in the needle compression test. The work of penetration was successfully related to the hydrogel water content, assayed by a gravimetric technique. Moreover, a fitting model was proposed to correlate the two variables (the water content and the work of penetration). The availability of a reliable tool is useful both in the quantification of the water uptake phenomena, both in the management of the testing processes of novel pharmaceutical solid dosage forms. [Copyright &y& Elsevier]

Abstract: In this study the feasibility of joining prilling and microwave (MW) assisted treatments as combined technique to produce controlled release alginate beads was tested. Beads were produced by prilling (laminar jet break-up) using different polymer concentrations and loaded with ketoprofen, a slightly soluble non-steroidal anti-inflammatory BCS class II drug characterized by low melting point. MW assisted treatments applied using different irradiating conditions were performed as drying/curing step. The effect of formulation conditions and process variables on drying kinetics, particle micromeritics, shape, surface and inner characteristics of the matrix as well as drug loading and drug release behaviour was studied (USP pH change method). The properties of MW dried particles were compared to those dehydrated by convective methods (room conditions and tray oven 105°C). Results showed that MW dried ketoprofen loaded beads were obtained in a very narrow dimensional range retaining shape and size distribution of the hydrates particles. Compared to the traditional drying methods, MW treatments were able to strongly increase drying rate of the hydrated beads achieving faster and controllable dehydration kinetics. Moreover, different regimes of irradiation affected structural properties of the particles such as matrix porosity as well as the solid state of the loaded drug. DSC, X-ray and FTIR analyses indicated complex chemical interactions between the drug and polymer matrix induced by MW, related with the regime of irradiation, that contributes to the differences in release profiles. In fact, MW treatments under different time and irradiating regimes are able to modulate drug release from alginate beads; high levels of irradiation led to beads suitable for immediate release oral dosage forms whereas the lowest regime of irradiation led to beads that achieved a prolonged/sustained release of the drug till 8h in simulated intestinal medium. This study showed that prilling in combination with microwave treatments is a useful and simple tandem technique to prepare dextran-based dried beads. [Copyright &y& Elsevier]

Abstract: Functional extracts from Fadogia ancylantha, Melissa officinalis and Tussilago farfara posses excellent antioxidant and good antimicrobial properties. The unprocessed extracts occur as sticky and low-water-soluble materials with penetrating smell. The loading onto maltodextrins matrix, widely used by food and cosmetic industries, is often unsatisfying. The industrial products are not always enough stable to preserve the functional properties of natural compounds, also giving practical difficulties for the manufacturing. This paper reports on the plant extracts encapsulation by spray-drying in a maltodextrin/apple-pectin based matrix. Physicochemical and technological characteristics, organoleptic and antioxidant properties of the resulting powders, were examined and compared to both unprocessed extracts and industrial products. The selected carrier and process conditions led to stable and handling microencapsulated powder forms with improved water dissolution rate. The made up powder also masked the extracts unpleasant smell making them suitable for successive manufacturing to produce functional components for foods or nutraceuticals purposes. [Copyright &y& Elsevier]