Pellets sustained-release

Capsules, sustained-release pellets 20, 30, 50, 60, 100 mg (c-//) Kadian (Alpharma)... 

The other related subcutaneous routes are dermojet (by which, drug is projected from a microfine orifice using a high velocity jet) and pellet implantation (which provides sustained release of the drug over weeks and months e.g. testosterone). 

Tapia C, Buckton G, Newton JM. Eactors influencing the mechanism of release from sustained release matrix pellets, produced by extrusion/spheronization. Int J Pharm 1993 92 211-218. 

Fig. 2—Absorption of verapamil after a single dose of a sustained release pellet formulation in six healthy volunteers. The position of the majority of pellets at each blood sampling was detected by X-rays. S, stomach I, intestine C, colon o, fasting , non-fasting.

Tramadol (Tramadolor long) is also available as sustained-release pellets with an identical release profile. 

Sustained Release Coating of Caffeine Pellets page 2... 

See also Sustained Release Coating of Diclofenac Pellets ... 

Diclofenac Spheronized Pellets for Sustained Release Coating (30%)... 

Scott, D., and Hollenbeck, R. Design and manufacture of a zero-order sustained-release pellet dosage form through nonuniform drug distribution in a diffusional matrix. Pharm. Res. 8 156-161, 1991. 

The pharmaceutical and biological availability of eight commercial furose-mide preparations was compared including two products with modified release properties [67], an enteric-coated tablet and a sustained-release preparation, in the form of a capsule containing diffusion pellets [28], A correlation between the rate of dissolution of different techniques and the area under the plasma concentration time curve was documented. The sustained-release preparation and the enteric-coated formulation clearly showed different pharmacokinetic behavior compared with conventional tablets. Although the literature mentions the maximal absorption at pH 5.5, the modified release formulations only showed a relative bioavailability of 80%. 

Sustained release intravitreal dexamethasone implants have a potential use in reducing ocular inflammation and treating PVR. The device consists of a 5 mg pellet of dexamethasone coated with 10% PVA and EVA giving a mean release rate of 1.2 0.1 pg/hr over a period of 5 months. A slow release daunomycin implant was fabricated by loading the polysulfone capillary fibre with 1% w/w of daunomycin in tristearin. The controlled release is attributed to the diffusion-retardant properties of the fat. An experimental evaluation of the kinetics and efficacy of this device in a rabbit model at 15 fig and 30 fig/ device resulted in a therapeutically sustained level of daunomycin for up to 21 days after device implantation. Exhausted devices have to be removed surgically, which is an important limitation. 

J. G. Devane, M. Kavanagh, and J. G, Kelly, Dose proportionality and steady-state bioequivalence of rerapamil sustained-release pellet-filled capsules, Cur. Ther. Res., 50 720-730 (1991). 

Joseph, A.A. Hill, J.L. Patel, J. Patel, S. Kincel, F.A. Sustained release hormonal preparations xv release of progesterone from cholesterol pellets in vivo. J. Pharm. Sci. 1977, 66, 490-A93. 

Amighi, K. Moes, A. Influence of plasticizer concentration and storage conditions on the drug release rate from Eudragit RD30D fihn-coated sustained-release theophylline pellets. Fur. J. Pharm. Biopharm. 1996, 42 (1), 29-35. 

Lorck, C.A. Grunenberg, P.C. lunger, H. Laicher, A. Influence of process parameters on sustained-release theophylline pellets coated with aqueous polymer dispersions and organic solvent-based polymer solutions. Eur. J. Pharm. Biopharm. 1997, 43, 149-157. 

Until recently, hot-melt extrusion had not received much attention in the pharmaceutical literature. Pellets comprising cellulose acetate phthalate were prepared using a rudimentary ram extruder in 1969 and studied for dissolution rates in relation to pellet geometry. More recently, production of matrices based on polyethylene and polycaprolactone were investigated using extruders of laboratory scale. Mank et al. reported in 1989 and 1990 on the extrusion of a number of thermoplastic polymers to produce sustained release pellets.A melt-extrusion process for manufacturing matrix drug delivery systems was reported by Sprockel and coworkers.As one can see, a review of the pharmaceutical scientific literature does not elucidate many applications for hot-melt extrusion in this field. 

Follonier, N. Doelker, E. Cole, E.T. Evaluation of hot-melt extrusion as a new technique for the production of polymer-based pellets for sustained release capsules containing high loading of freely soluble drugs. Drug Dev. Ind. Pharm. 1994, 20 (8), 1323-1339. 

Factors Affecting Drug Release from Sustained-Release Film-Coated Pellets Using Acrylic Aqueous Dispersions, 6th International Conference on Pharmaceutical Technology, June, 2, 1992. 

Schmidt, P.C. Niemann, F. The miniwid-coater. HI. Effect of application temperature on the dissolution profile of sustained-release theophylhne pellets coated with eudragit RS 30 D. Drug Dev. Ind. Pharm. 1993, 19, 1603-1612. 

In contrast to layering processes, extrusion-spheronization can be used to manufacture pellets with sustained-release characteristics without the application... 

Immediate-release formulations typically consist of the drug substance, fillers such as mannitol and lactose and binders such as gelatin, gelatin hydrolysates, and polyvinylpyrolidone. Cross-linked biopolymers based on collagen derivatives are used for sustained-release pellets. See Refs. ° for a detailed discussion on the formulation and processing variables. 

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