Powder formulations

Table 2. Melt-Mixed PVC Coating Powder Formulation ...

The colorant s chief disadvantages ate its iaabiUty to blend well with the other iagredients usually found ia powder formulations, its tendency to produce blue undertones, and its abiUty to catalyze the oxidation of perfumes. 

Only one detergent lipase, ie, Lipolase introduced by Novo in 1988, has been marketed. The first household powder detergent containing Upase was introduced in Japan in the same year in Europe and the United States in 1990—1991. Lipase is often incorporated into the new compact powder formulations. 

Production in the USA is 350000 tonnes annually of which 30% is used in baking-powder formulations, 20% in animal feedstuffs, 15% in chemicals manufacture, 11% in pharmaceuticals, 9% in fire extinguishers and the remaiiung 15% in the textile, leather and paper industries and in soaps, detergents and neutralizing agents. 

Several of these compounds and their derivatives are commercially and industrially important. Urea has already been mentioned on p. 311. Again, world production of chloroisocyanurates, (C1NC=0)3, in 1987 was ca. 80000 tonnes (50000 tonnes in USA alone, of which 75% went for swimming pool disinfection and most of the rest for scouring powders, household bleaches and dishwashing powder formulations). 

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. 

Wettable powder formulations can be mixed using the procedure described above with the exception that some of the second half of the water should be used to cream the test item into a paste type mixture which can then be poured into the first half of the water. Numerous rinsings will again be required to ensure that the entire test item is removed from its original container and, hence, thoroughly mixed with the second half of the water. 

As the concentration of parathion in the propylene glycol solutions is increased, it follows that the area covered by the solution is decreased. That this is a factor in toxicity is indicated by the greater toxicity of the 10 mg. per ml. solution than the 50 mg. per ml. solution. This relationship appears to be true also of the various dry preparations, in that the 1% powder is somewhat more toxic than the 15%. The addition of water to convert the powder to paste does not appreciably influence the toxicity. In comparable concentrations the wettable powder formulation is less toxic than the propylene glycol solution. 

The use of pure gamma isomer of hexachlorocyclohexane on livestock has also been worked out. It has been found possible to use the wettable powder formulation dispersed in water as a spray on livestock for control of flies, lice, and ticks. Proper dosage and application must be used, of course, but this is again indicative of the safety factor of this insecticide. 

This section addresses the design of immediate-re-lease powder formulations for hard gelatin capsules. In general, powder formulations for encapsulation should be developed in consideration of the particular filling principle involved. The requirements imposed on the formulation by the filling process, such as lubricity, compressibility and/or compactibility, and fluidity can vary between machine types. Furthermore, the... 

The average value of the transfer factor (approximately 2300 cm2/hr) derived from all data in our study differs somewhat from the transfer factor of 3300 cm2/hr observed in a preceding study during the cultivation of carnations (Brouwer et al., 1992). However, that transfer factor had been derived from data on both high-volume spray (as in the present study) and dusting operations. The powder formulations showed an effective transfer of the residue to the body. Recalculated transfer factors for only high-volume applications showed an average of approximately 2500 cm2/hr. 

Routes of administration other than dietary ingestion should not be discounted. Livestock found dead near a cyanide disposal site had been drinking surface water runoff from the area that contained up to 365 mg HCN/L (USEPA 1980). The use of cyanide fumigant powder formulations may be... 

Arthur, F.H. 1994. Residual efficacy of cyfluthrin emulsifiable concentrate and wettable powder formulations applied to sealed and unsealed concrete. J. Stored Prod. Res. 30, 79-86. 

Nagel, K. M., Peck, G. E. Investigating the effects of excipients on the powder flow characteristics of theophyline anhydrous powder formulations. Drug Dev. Ind. Pharm., 29, 2003, 277-287. 

Liquid instillation and nebulised aerosols are the most common methods for pulmonary administration to experimental animals [22, 54, 109, 134], The use of pressurised metered dose inhaler (pMDIs) and dry powder inhaler (DPIs) in preclinical studies is limited by the need for formulation development, which often cannot be performed in early drug discovery due to short supply of test materials. A number of alternative techniques for intra-tracheal administration of coarse sprays and powder formulations have been described [9, 15, 21, 36, 71, 80, 99, 138],... 

Okamoto H, Aoki M, Danjo K (2000) A novel apparatus for rat in vivo evaluation of dry powder formulations for pulmonary administration. J Pharm Sci 89 1028-1035. 

Exubera (see also Exhibit 4.14) Exubera is an inhalable insulin for the treatment of type I and II diabetes. Each dose consists of 1 or 3 mg insulin in a powder formulation with sodium citrate (dehydrate), mannitol, glycine, and sodium hydroxide. 

The finished form is a sterile, lyophilized powder formulated with tri-methamine, mannitol, and sucrose as excipients. 

Effect of Physical State on the Stability of Dry Powder Formulations... 

Formulation of dry powders for inhalation must rely on a very short list of excipients to fulfill the customary roles of diluent, stabilizer, solubilizer, processing aid, and property modifier (e.g., flow enhancer). In the United States, only a few materials are approved for use in inhalation products, and of those (e.g., propellants, surfactants) many are of little help in dry powder formulation. 

Oechslein et al. [50] studied various powder formulations of mucoadhesive polymers for their efficacy to increase the nasal absorption of octreotide in rats. Although... 

In a study performed in rabbits, rhG-CSF in a powder formulation (aerodynamic diameter < 4 pm) was insufflated via an intratracheal tube and compared to intratracheal instillation of a solution of the drug. In this study it was shown that a direct relation exists between the amount of protein that was deposited deep into the lung and the relative bioavailability [33]. 

Dry powder inhalers are generally described as breath actuated devices, because the inspiratory airstream releases the dose from the dose system and supplies the energy for the generation of fine drug particles from the powder formulation. Because the efficiency of dose release and powder disintegration increases with increasing inspiratory flow rate for most DPIs, these devices would be better described as breath controlled devices. In Section 3.9, the effect of resistance and clinical conditions on the flow curve and relevant flow parameters for DPIs are discussed. 

Powder container. Dry powder inhalers may contain the dry powder formulation in many different forms. The first DPI, the Spinhaler contained single doses in capsules. Other systems, like the Diskus or Diskhaler may contain the metered dose in blisters, whereas systems like the Turbohaler , or Novolizer , have multi-dose containers. 

In Section 3.5.3, dry powder inhalers have been referred to as breath-controlled devices. The efficacy of dry powder inhalation is a function of many factors, influencing the delivered dose of fine particles and the deposition of these particles in the respiratory tract. Figure 3.4 shows that DPI performance is influenced both directly and indirectly by the design of the inhalation system. The powder formulation, the dose (measuring) system and the powder disintegration principle have to be designed correctly for release of sufficient fine drug particles in... 

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