Effects of moisture on the pressing of pharmaceutical powders

Abstract

The effects of moisture on the rheological and elastic-plastic characteristics of compressible powders and the qualitative characteristics of tablets of aspartame-containing sweetener were studied. Theoretical and experimental studies identified the need for additional stages of moistening tableting material in pressing techniques.Aspartame-containing sweetener tablets have a number of advantages over others, namely the absence of energy content, a taste which is virtually identical to that of sugar, and the absence of the aftertaste typical of other sweeteners.Introduction of aspartame-containing sweetener tablet production involves a number of complications, making pressing difficult. It is therefore necessary to identify their causes and to optimize the technical process.Moisture is known to have direct effects on the plastic properties of particles -more moist materials are generally more plastic, while dry materials have elastic properties [1]. The presence of free moisture on particle surfaces helps to reduce friction when particles come closer together and also between the powder and the surface of the matrix. This leads to increases in the fluidity of powders [2] and decreases in friction when tablets are extruded from the matrix. Absorbed water also decreases the surface energy of crystals and increases the adhesion of tablets to the matrix and die surfaces and decreases their strength [3].Thus, published data provide evidence that the moisture of powders is an important factor in direct pressing technology, optimization of which allows increases in equipment productivity, increases in the quality of the ready product, and reductions in cost.The aim of the present work was to optimize the technology for tableting a standard sweetener containing 33.3% aspartame, 4.0% leucine, 4.0% sodium carboxymethylcellulose (NaCMC), and 58.7% lactose [4].The effects of moisture on the following were studied:-the rheological properties of tableting material (flowability, bulk density); -the energy characteristics of direct pressing (plastic particle deformation onset pressure and the pressure of extrusion of tablets from the matrix;-the quality parameters of tablets. MATERIALS AND METHODS Materials.Anhydrous lactose for direct pressing, Granulac-70 (Meggle, Germany) with a moisture content of 4.5 -5.5%, aspartame Powder-200 (HSC, Holland), leucine (USP 26), NaCMC (Cecol 5000), and water (Pharmacopoeia Article FS-42-2619-97) were used.Apparatus. A laboratory-scale hydraulic press with pressing pressures of up to 250 kgf/cm 2 , a matrix, a 5.2-mm diameter die, an MKI pointer micrometer with a precision of 0.01 mm, a Shimadzu balance model 200 (precision 0.001 g), an RTM-41 tableting press, and apparatus for assessing erosion, disintegration, and dissolution as specified in the State Pharmacopoeia, 11th Edition, were used.Methods. Experimental mixtures were prepared by placing 5.87 g of lactose in a mortar and moistening with different quantities of water. This was followed by addition of 3.33 g of aspartame, 0.40 g of leu...

Role of FDG‐PET as a biological marker for predicting the hypoxic status of tongue cancer

“…This mixture was stored at 50% relative humidity and ambient temperature for 1 month. The moisture equalizes electric charges on the particle surfaces26 and therefore increases the flowability 27. In addition water can act as lubricant during tableting and even be part of bonding (hydrogen bonding and liquid bridges) during compression 26.…”

Water Determination in Solid Pharmaceutical Products Utilizing Ionic Liquids and Headspace Gas Chromatography

“…When pharmaceutical compounds contain different concentrations of water, it affects the physiochemical properties of the finished drug formula. [1][2][3][4][5][6] If the water content is increased above a critical threshold, microorganisms are able to grow in drug formulations. 5 Microorganisms can be harmful, causing medications to have adverse effects.…”

“…During manufacturing, the presence of water on the surface of drug formulation will modify the electrostatic charge and surface energy causing variations in solid flow properties. [2][3][4][5][6] However, when there is excessive water, an increase in cohesion and adhesion is observed which decreases the flow properties. 4,5 When there is a disruption in flow in the hoppers (i.e., arching and bridging), it can lead to halts in production or compound segregation.…”