Semi-solid filling

Capsules have traditionally been used to contain powder or granule formulations but in recent years have been adapted to contain oily liquid as soft gelatin capsules. However, hard gelatin capsules, stored under the high temperature and high humidity conditions, tend to be more brittle than soft capsules because the capsule shell is thinner. 

Excipients Gelatin capsules Appearance % broken HPMC capsules Appearance % broken  

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Shah, N.H. Phuapradit, W. Ahmed, H. Liquid/semi-solid filling in hard gelatin capsules formulation and processing considerations. Bulletin Technique Gattefosse 1996, 89, 27-37. 

One-piece capsules containing a liquid or semi-solid fill. 

There are a number of applications for liquid/semi-solid filled capsules ... 

Solvents (A.S.C., 1986 Dick, 1987) - Solvents are used in evaporation type adhesives and sealants. They act as the carrier in which the base polymer is dissolved to provide low viscosity solutions that can accommodate fillers and otheradditives. Butyl rubber solutions are made with 50 to 70% rubber and 30 to 50% solvent. These are the bases of products which vary from unfilled viscous liquids to semi-solid filled sealants. Solvent release sealants generally range from 70 to 80% total solids. The solvent level is chosen so that adhesive or sealant is easy to apply and wets the adherend surface. After application, the solvent evaporates from the glue-line leaving the polymer bonded to the adherend. 

Table 4. Stability of liquid or semi-solid filling capsules after storage. The value in...

Softened water is often used for washing containers before filling with liquid or semi-solid preparations and for cooling systems. Unless precautions are taken, the microbial count in a cooling system or jacketed vessel will rise rapidly and if faults develop in the cooling plates or vessel wall, contamination of the product may occur. 

Nonaqueous liquids, semi-solids, and dry powders dry heat at 160°C/120 minutes then dry heat under alternative conditions of time and temperature to achieve a sterility assurance level of 10 6 then an alternative to dry heat, e.g., ionizing radiation with a minimum absorbed dose of not less than 25 kGy then a validated alternative irradiation dose (according to ISO 11137) then aseptic filtration and aseptic processing and then the use of presterilized components and aseptic compounding or filling... 

Orai concentrate soiutions Roxicodone intensoi, OxyFAST, and Oxydose 20 mg/mL solution are highly concentrated solutions. Take care in prescribing and dispensing this solution strength. Fill dropper to the level of the prescribed dose (1 mL = 20 mg 0.75 mL = 15 mg 0.5 mL = 10 mg 0.25 mL = 5 mg). For ease of administration, add dose to approximately 30 mL (1 fluid oz) or more of juice or other liquid. May also be added to applesauce, pudding, or other semi-solid foods. The drug-food mixture should be used immediately and not stored for future use. 

Rowley, G. 2004. Filling of liquids and semi-solids into hard two-piece capsulSSidrmaceutical Capsules, eds. F. Podczeck, and B. E. Jones, 2nd ed. 169-194. Bath The Batch Press. 

The mixtiue is cooled to room temperature, the flask is filled two-thirds full with water, and stirring is continued for five minutes. The xylene solution is separated, washed with water, dried over calcium chloride, filtered, and distilled under reduced pressure. After removal of the solvent, the tricarbomethoXy-methane distils at 128-142°/i8 mm. The yield of crude product is 50-51 g. (47-48 per cent of the theoretical amount). This material becomes semi-solid on cooling. 

Two-piece capsule shells which can be filled with powders, pellets, semi-solids or liquids. 

The fill can be either a solution or a suspension, liquid or semi-solid. The main limitation is that the fill must be compatible with the shell. The main incompatibilities are high... 

Semi-solid products have been traditionally packed in collapsible tin tubes. Metal tubes are a potential source of metal particles in ophthalmic products, and so the tubes have to be cleaned carefully prior to sterilisation. Also, the final product must meet limits for the number of metal particles found. Plastic tubes are not suitable because of their non-collapsible nature, which causes air to enter the tube after withdrawal of each dose. However, collapsible tubes made from laminates of plastic, aluminium foil and paper are a good alternative to tin tubes. Laminated tubes fitted with polypropylene caps can be sterilised by autoclaving, whereas tubes fitted with polyethylene caps are sterilised by gamma irradiation. The tubes are usually filled aseptically, sealed with an adhesive and then crimped. 

If. in place of bringing two solutions in contact with each other, they be separated by a solid or semi-solid, moist, colloid layer, diffusion takes place in the same way through the interposed layer. Advantage is taken of this hurt to separate cryst oids from colloids the process of dialyeis. The mixed solutions of crystalloid and coUoid are brought into the inner vessel of a dialyser. Fig. 13, whose bottom consists of a layer of moist parchment paper, while tiae outer vessel is filled with pure water. Water... 

At the start of a test the cylinder is completely filled by the solid/liquid mixture which can exhibit the characteristics of a slurry, where both filtration and consolidation processes take place, or by a networked semi-solid where consolidation commences from the start of the test. In general the mixture will be concentrated and/or composed of fine particulates that do not settle appreciably under gravity. The piston is introduced to the open end of the cylinder and the constant applied force causes pressure to be generated within the cylinder. Liquid is expelled through the filter medium and collected in either a measuring cylinder or, in more sophisticated units, a vessel mounted on a load cell or electronic balance. The volume or mass of liquid is measured at various time intervals from the start of expression. The thickness of suspension (or cake towards the end of the test) in the cylinder can be calculated from a knowledge of the volume of liquid removed from the cylinder, or from measurements of the piston displacement from the beginning of the test should an appropriate transducer be fitted. 

Gas-filled plastics are polymer materials — disperse systems of the solid-gas type. They are usually divided into foam plastics (which contain mostly closed pores and cells) and porous plastics (which contain mostly open communicating pores). Depending on elasticity, gas-filled plastics are conventionally classified into rigid, semi-rigid, and elastic, categories. In principle, they can be synthesized on the basis of any polymer the most widely used materials are polystyrene, polyvinyl chloride, polyurethanes, polyethylene, polyepoxides, phenol- and carbamideformaldehyde resins, and, of course, certain organosilicon polymers. 

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