Various medicinal forms of levothyroxine are one of the most prescribed hormonal drugs in clinical practice. Thus, the products of thyroxine by the frequency of destination in the US are on the 13-th place.

The world market for products of thyroid hormones in terms of sales, according to IMS Healht, in 2002, amounted to 915 million euros, similar to the Russian market in 2001, according to RMBC, was 7,354 million dollars. For the period of 1997-2002 the growth of the volume of sales of drugs levothyroxine the world pharma market amounted to 18% (at an average annual rate of growth of +3,6%), which testifies to the fact that this market is stable and constantly growing.

Of significant prospects of development of the market is evidenced by the results of epidemiological studies. WHO estimates that about 600 million people on the earth suffer from diseases of the thyroid gland and 1.5 billion people are faced with the risk of iodine deficiency diseases [1, 40], which does not augur decrease in the number of consumers of the preparations of thyroid hormones in the next 10-15 years. When forming the forecast estimates the potential of development of the market of products of thyroid hormones should take into account several important factors.

First of all, the results of research in recent years testify to the wider dissemination of the syndrome, hypothyroidism with thyroid pathology in various cohorts of the population than previously thought. So, in particular, the results of the studies showed a higher frequency of latent and manifest hypothyroidism in different age groups of the population in the united states from 3 to 21% [16, 27], than it was supposed earlier. In Scotland frequency manifest hypothyroidism was detected in the 0.2-2%, and subclinical - from 2% to 10% of the population [28]. In Vikgemskom study [38], where were examined inhabitants of England (random sample), it was found that the frequency of new cases of spontaneous hypothyroidism is for women to 3.5 cases per 1000 persons in a year.

Growth of registration of the number of thyroid diseases in recent years, largely due to and improve the detection rate of this class of pathology, that is the result of the rapid development of diagnostic technologies, especially due to the introduction of the in medical practice of immunochemical methods for determining the concentration of tireotropina and methods of ultrasonic imaging of the thyroid gland.

Work in the field of evaluation of risk of development of thyroid pathology, including running with hypothyroidism syndrome, has identified high-risk groups that lawfully brought the issue of the conduct in these groups of the population screening [12]. Given the high medical and social significance of this pathology and the interest to it, it is clear that the conduct of screening, undoubtedly, affect the level of detection of thyroid pathology.

Deep concern about the health of the public caused by a situation with thyroid pathology and in the countries of the CIS. First of all worried about the huge increase in the incidence of various forms of non-toxic goiter. Thus, in some regions the incidence reaches 30-70% of the population [2, 3, 8]. Such a high level of morbidity is caused by two major factors, firstly, the social cataclysms that have led to a deterioration of the power of significant layers of the population, changes in the structure of power due to reduction of consumption yodnesuschih products; secondly, the destruction of the state system of the prevention of goiter and iodine deficiency states [13].

The situation has aggravated in some regions of Russia, Ukraine and Belarus combination of the impact of the above mentioned factors and radiation, which leads to the formation of a more severe variants of the disease.

Forecasts of development of the situation with thyroid pathology in the CIS countries are mainly to the fact, that will increase the frequency of hypothyroidism. Under the current severity of endemic process still remains low tension endemic settings, and in the structure of morbidity prevail early, initial forms of goiter. Previous experience suggests that there is a clear trend, with an increase of the length of the disease increases the frequency of such outcome as symptomatic hypothyroidism.

In addition, in the areas goitrous epidemics usually in parallel, an increasing number of surgical interventions on the hardware on the nodal forms of goiter, thyroid cancers, etc. As experience shows [1], hypothyroidism is the most common outcome of surgical treatment.

Is accumulating facts about the role of hypothyroidism as an independent risk factor for development of cardiovascular pathology. Shows the effects of development in hypothyroidism - hypercholesteremia, triglitseridemii, hyperhomocysteinemia [5, 22, 30], which usually are reduced exclusively when restoring hormone balance. These findings establish a more widespread use of drugs of levothyroxine with cardio-vascular pathology, but make new demands to the drugs of this group.

All of the above arguments indicate, in our opinion, the prospect of the more widespread use of drugs of levothyroxine in medicine, which should lead to an increase in their sales. On the other hand, a higher frequency of use of the data of pharmaceuticals increased the frequency of their use in non-standard conditions. No doubt, will increase the number of cases of use of the combination of several diseases, increase the frequency combinations of destination with other drugs that sets new requirements to safety, predictability, reproducible effects and standardization of the products.

In spite of the rich history of the use of drugs of levothyroxine [35] for the treatment of diseases of the thyroid gland, many aspects of their pharmacodynamics, pharmacokinetics and Pharmtechnology remain poorly investigated or discussion. Therefore, in this publication we would like to outline a circle of the most important problems of the use of drugs of levothyroxine in endocrinology and evaluate the possibilities of modern Pharmtechnology in questions of optimization of the quality of the data medicines.

At the global pharmaceutical market of firms-manufacturers, more than 70 trade names of drugs of levothyroxine as a widely-known brands, but also generics, which puts before the doctors and organizers of public health challenge of choosing the optimal for the work of the drugs . On the Russian pharmaceutical market at the moment registered seven trade names of drugs of levothyroxine.

The most well-known trade names of drugs of levothyroxine (which comprise the largest sector of the sales world market) - eutiroks (Merck, Germany), Synthroid ("Abbott lab.", USA), Levotroid ("Roche", Switzerland), the promotion of which the market has implemented a policy of globalization, and each of these brands now presented on the markets of 50-70 countries of the world, which gives a number of advantages to analogues. Firstly, in connection with the fact that the people with the long-term (sometimes for life) take these medicines, when you move them to different regions do not suffer from the quality of their life and are the problems of translation into the local regional brand (which can sometimes be very significantly different in its pharmacodynamic and pharmacokinetics). Secondly, in connection with the large volume of production from these brands of drugs has a developed structure of the presented doses in the range of 12.5 to 175 micrograms (in increments of 12.5 mcg), to accurately and safely pick up the necessary modes of therapy . It should be noted that the presented on the pharmaceutical market of the producers of a wide range of dosage forms of levothyroxine - tablet, injection and suppositories, allows you to work effectively with children and heavy coma sick.

Unfortunately, so far in the arsenal of the Russian endocrinologists there are only a tableted dosage form of thyroxine, although there is a necessity of a conclusion to the market data and dosage forms of drugs. But it should be remembered that the pharmacodynamics and pharmacokinetics of such medicinal forms differs significantly from that of the tableted preparations and therefore require a substantial volume of methodological work and data of the literature on these issues, in order to avoid in the process of treatment of unwanted side effects. Along with a high quality and innovativeness of these drugs should be noted huge base of testing in different countries and at different cohorts of patients, as well as a large number of diverse scientific publications, which allows researchers to compare the results of the therapy. A significant number of examinations at the registration in various countries of the world also increases the safety profile of these drugs by reducing the capacity of the various errors.

The leading theme of the debate of the last years on the use of medicinal products with a low therapeutic index (showing the therapeutic effect only in a relatively narrow range of doses, when there is less than a 2-fold difference between the average lethal dose and the average effective, which include pharmaceuticals levothyroxine) - the safety and quality of generic drugs [14, 24]. The problem of generics is highly relevant for the Russian pharmaceutical market, where, according to RMBC, their sector in the group of levothyroxine was in 2003, 94%, which is significantly higher compared to that sector of the developed foreign countries.

History of use in medical practice of original and generic drugs reflects the permanent conflict between the real properties of drugs and economic background of the problem.

At the moment has accumulated a considerable number of works, the evidence of therapeutic effectiveness of a number of commercial preparations of levothyroxine [15, 19, 23, 25]. This question in the literature is discussed in two planes: the quality of the products and features of pharmacokinetics and pharmacodynamics of reproducible different trade names of drugs.

One of the problems is the exact dosing of microgram quantities of the active substance in the tablets. So, in a generic in the study Staffer, Szpunar (1980) shows the levothyroxine tablets only 57% of the declared and in the study of Dong et al. (1986) the content of the active substance ranged from 71 up to 127% from the declared.