Injection suspensions

One of the most difficult parenteral dosage forms to formulate is a suspension. It requires a delicate balance of variables to formulate a product that is easily resuspended and can be ejected through an 18-to 21-gauge needle through its shelf life. To achieve these properties it is necessary to select and carefully maintain particle size distribution, zeta potential, and rheological properties, as well as the manufacturing steps that control wettability and surface tension. The requirements for, limitations in, and differences between the design of injectable suspensions and other suspensions have been previously summarized [17b, 18,19]. 

Two basic methods are used to prepare parenteral suspensions (a) sterile vehicle and powder are combined aseptically, or (b) sterile solutions are combined and the crystals formed in situ. Examples of these procedures may be illustrated using Penicillin G Procaine Injectable Suspension USP and Sterile Testosterone Injectable Suspension USP. 

Finally, one of fhe most recent and most interesting approvals of a new formulation of paclifaxel was fhe approval of the agent ABl-007 (Abraxane ) (Abraxis Oncology, Schaumburg, IL, U.S.A.) (paclifaxel protein-bound particles for injectable suspension [albumin-bmmd]). It is indicated for treatment of breast cancer after failure of combination chemotherapy for metastatic disease or relapse within 6 months of adjuvant chemotherapy. Prior therapy should have included an anthracycline unless clinically contraindicated. The endpoint for that pivotal trial of Abraxane vs. paclitaxel was a... 

Injection Suspension (Beta-Phos/AC, Celestone Soluspan) 3 mg acetate/3 mg betamethasone sodium phosphate. 

Injection Suspension 20 mg/ml (Depo-Medrol), 40 mg/ml (Adlone-40, Depo-Medrol, Depopred, Depmedalone, Med-Jec-40, Methylcotol), 80 mg/ml (Adlone-80, Depmedalone, Dep Medalone 80, Depoject-80, Depopred, Depo-Medrol, Medral-one 80, Methacort 80, Methyl cotolone). 

Recommended dosage and monitoring requirements Sandostatin injectable solution is usually administered subcutaneously in initial doses of 50 to 100 pg two or three times daily. Upward dose titration is frequently required. Sandostatin LAR Depot injectable suspension should never be administered intravenously or subcutaneously. Patients not currently receiving octreotide acetate should begin therapy with subcutaneous injections and then can be switched to the depot injection of 20mg intragluteally at 4-week intervals for 3 months. 

Debruyne F et al Abarelix for injectable suspension first-in-class gonadotropin-releasing hormone antagonist for prostate cancer. Future Oncol 2006 2 677. [PMID 17155895]... 

Testosterone injectable suspension Testamone, Testaqua Androgen deficiency breast cancer delayed puberty in boys Intramuscular... 

Octreotide acetate injectable suspension (octreotide long-acting release Sandostatin LAR) is a slow-release formulation in which octreotide is incorporated into microspheres. It is instituted only after a brief course of shorter-acting octreotide has been demonstrated to be effective and tolerated. The microspheres must be carefully put into suspension and immediately injected into a gluteal muscle. Injections into alternate gluteal muscles are repeated at 4-week intervals in doses of 20-40 mg. Octreotide is extremely costly. 

Somatropin injectable suspension (Nutropin Depot) is a long-acting preparation of rhGH enclosed within biodegradable microspheres. These microspheres degrade slowly after subcutaneous injection such that the rhGH is released over about 1 month. 

Side effects of the long-acting somatropin injectable suspension have included injection-site nodules that persist for 5-7 days (96%), edema, arthralgias, transient fatigue (24%), mild-moderate nausea (24%), and headache (36%). 

Conifer needles also contain volatile products which are mainly composed of mono- and sesquiterpenoids. The volatile turpentine constituents are used in the production of flavors and perfumes and in various technical and pharmaceutical products. The turpentine and rosin production of trees can be increased considerably by injecting suspensions of pitch canker fungus or chemicals such as "paraquat" (1,r-dimethyl-4,4 -bipyridinium salt) which has been found to be very effective. 

Highest High Inhalation aerosols and solutions injection injectable suspensions Ophthalmic solutions and suspensions transdermal ointments and patches nasal aerosols and sprays Sterile powders and powders for injections and inhalation powders ... 

Injection, Suspension A liquid preparation, suitable for injection, which consists of solid particles dispersed throughout a liquid phase in which the particles are not soluble. It can also consist of an oil phase dispersed throughout an aqueous phase, or vice-versa. 

Sterile suspensions (injectable and ophthalmic) have characteristics that are not commonly shared by other suspension systems, such as ease of resuspension, drainage, absence of foreign particulate matter and pyrogens, and syringeability in the case of injectable suspensions. 

Hussain MA, Aungst BJ, Maurin MB, Wu LS. Injectable suspensions for prolonged release nalbuphine. Drug Dev Ind Pharm 1991 17(1) 67-76. 

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