482 Indian Journal of Pharmaceutical Education and Research | Vol 50 | Issue 3 | Jul-Sep, 2016 Original Artcle www.ijper.org Application of TLC-Densitometry for Analysis of Estradiol Hemihydrate in Dosage Forms Dobrina Doncheva Tsvetkova 1 , Danka Petrova Obreshkova 1,2 , Stefka Achkova Ivanova 1,2 , Bozhidarka Hadjieva 3 , Peter Yordanov Atanasov 4 1 Medical University-Sofa, Faculty of Pharmacy, Department of Pharmaceutical Chemistry, 2 Medical University-Plovdiv, Faculty of Pharmacy, Department of Pharmacognosy and Pharmaceutical Chemistry, 15A Vasil Aprilov Str., Plovdiv 4002, BULGARIA. 3 Medical University-Plovdiv, Medical College, 15A Vasil Aprilov Str., Plovdiv 4002, BULGARIA. 4 Clinic of Internal Diseases UMHATEM ”N. I. Pirogov”-SOFIA, BULGARIA. ABSTRACT The aim of current study was the application of validated TLC-densitometric method for identification and determination of Estradiol hemihydrate in dosage forms. The applied TLC conditions were: Silicagel G 60 F 254 glass plates; mobile phase: chloroform : acetone = 90 : 10 v/v, migration distance of mobile phase: 120 mm, UV-detection at  = 254 nm. All of the experimental results for the content of Estradiol hemihydrate correspond to the respective confidence interval: Estrofem table: 1.78 mg ÷ 2.12 mg; Femoston F1 table: 1.88 mg ÷ 2.2 mg; Femoston F2 table: 1.99 mg ÷ 2.19 mg; Trisequens T1 table: 1.78 mg ÷ 2.18 mg; Trisequens T2 table: 1.92 mg ÷ 2.12 mg; Trisequens T3 table: 0.97 mg ÷ 1.17 mg. The proposed validated TLC-densitometric method is appropriate for quality control of Estradiol hemihydrate in commercially available tablets. Key words: Estradiol hemihydrate, TLC, Densitometry, Tablets, analysis, Determination. DOI: 10.5530/ijper.50.3.23 Correspondence: Dobrina Tsvetkova, Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Medical University-Sofia, Dunav str. N : 2, 1000, Sofia, BULGARIA. Tel no: +359 02 9236 566 E-mail: dobrinka30@abv.bg INTRODUCTION Osteoporosis is designated as the third socially signifcant disease in the world, after cardiovascular and oncological diseases and the forecast is to take second place in 2020. 1 Osteoporosis is caused by the reduced levels of estrogen, which in postmenopausal women are 1/10 of the levels in premenopausal women. 2 Lowered levels of estrogen lead to: 1) increase of oxidative stress; 2) apoptosis of osteoblasts; 3) rapid loss of bone mass due to increased rate of degradation of the bone tissue by osteoclasts; 4) a long life of osteoclasts compared to osteoblasts; 5) reduction of the absorption and utiliza- tion of calcium in bones. 3 Most pharma- cological agents used in the prevention and treatment of osteoporosis reduce bone resor ption or delay the total rate of bone turnover. For the prevention of fractures are applied: inhibitors of the activity of osteoclasts – bisphosphonates Rizedronate and Zoledro- nate, 4 selective estrogen receptor modulators Bazedoxifene 5 and Lasofoxifene 6 para- thyroid hormone, 7 Strontium ranelate 8 and antiresorptive agent Denosumab – a human monoclonal antibody IgG 2 . 9 Bisphosphonates cause adverse effects on gastrointestinal tract 10 : nausea, heartburn, scleritis and iritis (Alendronate). 11 Selective estrogen receptor modulators Bazedoxifene 12 and Raloxifene 13 reduce resorption activity by inhibition of the production of interleukin 6, tumor necrosis factor α and the number of osteo- clasts. Preclinical studies indicate that Strontium ranelate has a dual mechanism of action: 1) induces the bone formation by synthesis of bone collagen, alkaline phosphatase and osteocalcin; 2) inhibits the osteoclastogenesis by suppressing the differentiation and activity of osteoclasts. 14 Submission Date : 23-04-2016 Revision Date : 20-06-2016 Accepted Date : 23-06-2016