Progesterone dispersion

The hormone-releasing devices have a closer resemblance to standard methods of sustained release because they involve the release of a steroid compound by diffusion [198,199]. The Progestasert, a reservoir system, is shown in Fig. 16. Progesterone, the active ingredient, is dispersed in the inner reservoir, surrounded by an ethylene/vinyl acetate copolymer membrane. The release of progesterone from this system is maintained almost constant for 1 year. The effects of release are local, with none of the systematic side effects observed with orally administered contraceptives [200-207]. 

Incorporation of the steroidal drugs hydrocortisone and progesterone in complex with p-CD and HP-P-CD reduced the particle size for solid lipid nanoparticles (SLNs) below lOOnm. Steroids were demonstrated to be dispersed in the amorphous state. Compexation to CDs resulted in higher drug-loading properties for the more hydrophobic drug hydrocortisone and lower in vitro release for both drugs when they are complexed to CDs rather than their free form [31]. 

The PRID (progesterone-releasing intravaginal device), which consists of a stainless steel spiral covered with a silicone elastomer, with micronized progesterone (1.55 or 2.25 g) uniformly dispersed throughout. 

The CIDR 1380 Cattle Insert, which is a T-shaped delivery system comprising a nylon spine that gives form to the device, over which a layer of silicone is cured, and 1.38 g (10%w/w) of USP grade micronized progesterone is dispersed homogeneously throughout it. 

The Pig CIDR, which contains 2 g of progesterone that is homogeneously dispersed throughout a silicone matrix cured at low temperatures (below 120°C) over a polyester spine. 

This chapter will discuss (a) the production and characterization of LS formed by the melt dispersion technique, by the solvent evaporation method, and by the water/oil/water (w/o/w) double-emulsion method (b) the influence of preparation parameters on liposphere morphology and (c) the encapsulation efficiency and the release characteristics of two lipophilic model drugs, such as retinyl acetate and progesterone, and one hydrophilic drug, sodium cromoglycate (SCG), from the prepared LS. 

Two hydrophobic compounds, such as retinyl acetate and progesterone, and one hydrophilic drug, SCG, were considered as model drugs. LS were produced by the melt dispersion technique. 

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