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A directly compressible excipient has been developed by co-processing starch with magnesium silicate. The foregoing was achieved either by co-precipitation of magnesium silicate onto different types of starch or by dry granulation of maize starch with magnesium silicate. A variety of techniques (permeability, water retention/swelling, compression analysis, scanning electron microscopy, tensile strength and disintegration/dissolution studies) were used to characterize these systems. The permeability of the formulations produced using the two methods was evaluated experimentally using Darcy's permeability law. Magnesium silicate, as an anti-adhering agent, increases the permeability of both maize and partially pregelatinized starch, resulting in compacts of high mechanical strength, short disintegration time and low lubricant sensitivity. Such advantages are evident when the properties of the physical mixture of maize starch with magnesium silicate are compared with the co-precipitation and dry granulation techniques. Formulation with this novel excipient system, using paracetamol as a model drug, indicated its suitability as a single multifunctional excipient., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Chitin-silica represents a potentially useful superdisintegrant in many pharmaceutical applications. The "intimate" association between chitin and silica, without evidence of chemical reaction, creates an insoluble, hydrophilic, highly absorbent inert material. The new superdisintegrant is characterized by superiority in water uptake and water penetration, with no gelling hindrance effects, as well as compatibility with pharmaceutical drugs. In addition, it has an outstanding functionality that does not depend on swelling properties, as in the case of most conventional superdisintegrants. Chitin-silica offers good compressibility and compactability characteristics that may allow it to function as a pharmaceutical filler. Studies have shown that chitin-silica, as a superdisintegrant, is effective at all concentrations tested in tablet formulation.

Disintegrants and fillers represent important excipients for immediate-release solid dosage forms in many pharmaceutical applications. A new excipient based on the coprecipitation of chitosan and silica has been achieved. The "intimate" physical association between chitosan and silica creates an insoluble, hydrophilic, highly absorbent material, consequently, resulting in superiority in water uptake, water saturation for gelling formation, and compactability among other superdisintegrants. The new excipient has an outstanding functionality that does not primarily depend on water wicking and swelling properties. In fact, it translates it into superior disintegration characteristics with improved powder flow and compaction properties. Thus, the new excipient could act as a superdisintegrant and pharmaceutical filler at the same time. Studies have shown that chitosan-silica delivers superior performance in wet granulation formulations and is the only disintegrant that is effective at all concentrations in tablet formulation.

A new excipient was prepared using natural resources and bio-wastes such as sodium silicate, brine and date palm cellulose. The prepared excipient is water-insoluble silicate salt precipitated in date palm cellulose (WISS-DPC). The aim of this study was to evaluate the potential use of this new material as an excipient for formulating oral solid dosage forms. Diclofenac sodium and paracetamol tablets were manufactured using direct compression and wet granulation methods, respectively. The surface of the tablets was studied using AFM and SEM. FTIR and DSC provided a guarantee of compatibility of the excipient with the model drugs. The prepared tablets passed Pharmacopeial and Non-Pharmacopeial tests. Tablets prepared using WISS-DPC were harder, had rapid disintegration and rapidly dissolved compared to those produced with microcrystalline cellulose. The compactibility of the WISS-DPC was not affected by dilution with drugs or wet granulation. This new excipient could be used in pharmaceutical industry. [ABSTRACT FROM AUTHOR]

The aim of this research was to develop a cost effective and innovative pharmaceutical additive for multipurpose use in the pharmaceutical industry using Saudi Arabia's natural resources and bio-wastes. The waste substance, brine, and the naturally occurring compound, sodium silica, were reacted together to produce water insoluble calcium and magnesium silicate salts (WISS). The purity index WISS was compared with synthetic Mg silicae. The produced particle size was 1.994 µm. Date palm cellulose (DPC) with a high purity index (0.99) was produced from the biomass waste of the date palm tree. The DPC was used as a host for coprecipitation of synthetic calcium magnesium silicate within its chemical structure. The interaction between the cellulose polymer and silicates is physical in nature. The WISS-DPC was more flowable than DPC alone. SEM pictures show that the particles of the DPC were fibrous and irregular in shape, whilst the the WISSDPC showed more regular shape than DPC. Tablets prepared using WISS-DPC were harder and had lower disintegration time at all compression forces compared to those made with DPC. The produced excipient had excellent compaction and disintegration properties and could be used as a superdisintegrant and tablet binder in pharmaceutical industries. [ABSTRACT FROM AUTHOR]

An oral controlled release (CR) matrix system of Ambroxol hydrochloride was developed using a binary hydrophilic polymer mixture of chitosan (CH) and xanthan gum (XG) (1:1 w/w ratio). Two test tablet formulations were prepared using drug to polymer mixture ratios (D:P) of 1:1 and 1:3 (w/w), designated as T1 and T2, respectively. The in vitro drug release data was best fitted to the Higuchi equation. The 1:1 ratio (T1) demonstrated in vitro dissolution similarity with the commercial product, Mucosolvan LA. A preliminary in vivo study was performed using six volunteers. The study was designed to include open, randomized, single- dose, three-treatment, six-sequence, crossover (Williams design) under fasting conditions. The data showed that T1 was bioequivalent to Mucosolvan LA® after the administration of a single 75mg oral dose. Two in vivo, in vitro correlations (IVIVC) were established between Cmax versus the fraction of drug dissolved (FRD) after 4 hours, and AUC versus the ratio of fraction of drug dissolved (FRD) after 10 hours where a multiple point level C correlation of IVIVC was obtained. [ABSTRACT FROM AUTHOR]