Formulation process spray drying

In addition to detergency performance and feedstock economics, other factors related to the processing of these powder formulations must be considered, such as sulfonation/sulfation, crutcher slurry preparation, and spray drying. AS and AES are thermally and hydrolytically less stable than LAS. Care must be taken in spray drying to avoid decomposition and pluming problems. This may place a limitation on the levels of AS and AES in spray-dried laundry powders. 

Interestingly, the choice of LSDA is immaterial as long as its LSDR is 10 or less. The superior detergency of the above formulation using MES (TMS) as dispersant was confirmed by actual laundry bundle tests. It was also found that this type of formulation could be processed by spray-drying, drum-drying, or by various soap-drying processes. 

It was observed that this technique was able to produce microparticles with a mean diameter of approximately 10.17 + 3.02 pm in a reasonable to satisfactory yield depending on the formulation. This value was observed to be higher for the polymer weight ratio of 1 3 (87.00 + 4.25 %), which indicates that ESIOO improves the final result of the spray-drying process. According to the SEM analysis, the polymeric microparticles were shown to be quite similar in shape. Regardless of the formulation, they appeared to be mostly concave and asymmetric (Figure 12). 

Fine particle powders can be produced by various methods, such as micronization or spray drying. The physicochemical nature of these fine particles largely defines the stability of the bnlk powder, which in turn is critical to the long-term effective performance of the dry powder product. The section Fine Particles and the Solid State in this article is an introduction to understanding better the fundamental properties that underlie the behavior of bulk powders. Commentary on the various means of producing fine powders follows in the section Powder Production Formulation and Processing. ... 

Each spray-dried droplet forms a single particle whose size is determined by the droplet size, the dissolved solids of the feed solution, and the density of the resulting solid particle. For a given formulation and process, both the solid content and density of the powder remain constant within a batch and from batch to batch therefore, the distribution of the primary particle size is determined by the droplet size distribution. A narrowly distributed particle size can be achieved with a well-designed atomizer and controlled process parameters. 

Spray freeze drying also has been proposed as an alternative technology to produce light and porous particles for peptide and protein delivery. Liquid nitrogen is used as recipient agent, into which the formulation is sprayed. The formed microparticles are harvested and lyophilized eventually. DNase and monoclonal anti-IgE antibodies have been used to demonstrate the feasibility of this concept (Maa et al. 1999). Promaxx microspheres are manufactured in a phase-separation process between water-soluble polymers and therapeutically active protein that results in particles having a high protein payload of up to 90 percent (Brown et al. 1999). 

The first direct compression excipient, spray-dried lactose, was introduced in the early 1960s as a filler specifically designed for direct compression processes. Over many years, more direct compression API and excipients, especially diluents and binders, were developed. Since these are now commercially available, design of direct compression formulations is readily possible. However, despite the simplicity of the direct compression process, the pharmaceutical industry still produces most tablets by wet granulation methods.1... 

Microcrystalline Cellulose. Microcrystalline cellulose is a purified, partially depolymerized cellulose that occurs as a white, odorless, tasteless, crystalline powder composed of porous particles. It is widely used in pharmaceutical dosage forms, primarily as a filler-binder in oral tablets and capsules with both wet granulation and direct compression processes. Microcrystalline cellulose was marketed first in 1964 by the FMC Corporation under name Avicel PH in four different particle size grades, each with different properties.37 Addition of Avicel into a spray-dried lactose-based formulation overcame compressibility problems. At the same time, the lactose enhanced the flowability of the Avicel products available at that time. The direct compression tableting process became a reality, rather than a concept, partially because of the availability of Avicel. As of 2007, Avicel PH is commercially available in 10 types with different particle size, density, and moisture grades that have different properties and applications (Table 7.6).38 Other brands of microcrystalline cellulose are also available on the pharmaceutical market, including Pharmacel 101 and 102 from DMV International and Emcocel 50 M and 90 M from JRS Pharma. 

Microcrystalline cellulose is one of the most commonly used filler-binders in direct compression formulations because it provides good binding properties as a dry binder, excellent compactibility, and a high dilution potential. It also contributes good disintegration and lubrication characteristics to direct compression formulas. When compressed, microcrystalline cellulose undergoes plastic deformation. The acid hydrolysis portion of the production process introduces slip planes and dislocations into the material. Slip planes, dislocations, and the small size of the individual crystals aid in the plastic flow that takes place. The spray-dried particle itself, which has a higher porosity compared with the absolute porosity of cellulose, also deforms... 

Microcrystalline cellulose is the most compressible of any direct compression excipient. Producing a tablet of a given hardness requires less compression force for other materials. Therefore, it is usually mixed with another filler to achieve ideal compactibility and flowability of a direct compression formulation. Large particle size grades of microcrystalline cellulose are made by spray-dried processes to form dry and porous particle surfaces. The porous surfaces provide adsorption sites needed for fine dmg particles in low-dose formulations. However, microcrystalline cellulose contains trace amounts of peroxides that may lead to chemical incompatibility with oxidatively sensitive dmg substances.34... 

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