Estradiol transdermal system

Estradiol transdermal system is designed to deliver 17(beta)-estradiol continuously and consistently over a 3-or 4-day interval on application to intact skin. Three strengths of Alora systems are available, having nominal in vivo delivery of 0.05, 0.075, and 0.1 mg estradiol per day through skin of average permeability (interindividual variation in skin permeability is approximately 20%). Alora systems have contact surface areas of 18, 27, and 36 cm2 and contain 1.5, 2.3, and 3.0 mg of estradiol USP, respectively. The composition of the systems per unit active surface area is identical. Estradiol USP [17(beta -estradiol] is a white, crystalline powder that is chemically described as estra-l,3,5(10)-triene-3,17(beta)-diol, has an empirical formula of and has a molecular 

Estradiol-containing matrices are prepared by mixing acrylic adhesive (National Starch Durotac 1194), sorbitan monooleate (Arlacel 80), and estradiol at a ratio of 80-XK20IX), where X is the proportion (wt%) of estradiol. The matrix contains 25 estradiol (8% estradiol was saturated) for optimal permeation. 

Handbook of Pharmaceutical Manufacturing Formulations Semisolid Products 

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FIGURE 52-1. This low-dose estrogen transdermal patch, available as the trade name Estraderm (Estradiol Transdermal System), is transparent and about the size of a silver dollar. It releases small amounts of estrogen directly into the bloodstream at a constant and controlled rate to a female requiring estrogen replacement therapy for postmenopausal symptoms. 

A 47-year-old postmenopausal woman developed eczematous lesions at the sites of application of an estradiol transdermal system and subsequently at the sites of application of an estradiol gel (55). She was therefore given oral estrogen instead, but this promptly elicited a systemic pruritic rash. The causal link was in all instances confirmed by patch-testing. 

The estradiol transdermal system is indicated in the treatment of vasomotor symptoms associated with menopause. It is also used to treat female hypogonadism, primary ovarian failure, atrophic conditions (atrophic vaginitis or kraurosis vulvae), and in the prevention of osteoporosis (see Estrogen and Figure 48). 

An estradiol transdermal system made to contain 90.0-110.0% of the labeled amount of estradiol (C18H24O2) is analyzed using a sample solvent containing acetonitrile and water in a ratio of 50/50 (v/v) and mobile phase composition... 

This new dosage form recently was introduced to the pharmaceutical industry. Transdermal preparations now are commercially available for the alleviation of the symptoms of motion sickness (scopolamine), to provide symptomatic relief of angina pectoris (nitroglycerin), and for replacement estrogen therapy (estradiol), Transdermal systems offer advantages commonly associated with con-... 

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