G.Kumaraswamy et al./ Elixir Pharmacy 79 (2015) 30637-30641 30637 Introduction Amlodipine Besylate 1 , chemically is 3-ethyl 5-methyl (4RS)-2-[(2-aminoethoxy) methyl]-4-(2chlorophenyl)-6-methyl- 1,4-dihydropyridine-3,5-dicarboxylate benzene sulphonate, belongs to the class of Calcium channel blocker, used as anti- anginal. Molecular Formula – C 26 H 31 ClN 2 O 8 S , Molecular Weight – 567.1 Solubility - Slightly soluble in water and in isopropyl alcohol, sparingly soluble in dehydrated alcohol, freely soluble in methanol. Fig 01. Chemical structure of Amlodipine Besylate Atenolol: chemical name: (RS)-4-(2-hydroxy-3- Isopropylaminopropoxy) phenylacetamide, belongs to the class of β-adrenergic blocker, used as an antihypertensive drug. Molecular Formula – C 14 H 22 N 2 O 3 Molecular Weight – 266.34 Solubility – Soluble in ethanol, sparingly soluble in water. Fig 02.Chemical structure of Atenolol Fig.No.03.Chemical structure of Hydrochlorothiazide: Chemical name 6-chloro-3,4-dihydro-2H-1, 2, 4- benzothiadiazine-7-sulfonamide 1,1-dioxide Molecular formula: C 7 H 8 ClN 3 O 4 S 2 Solubile in water, methanol, ethanol, acetone ,Dimethyl formamide. From the literature survey it was found that many methods are available for determination of Amlodipine Besylate, Hydrochlorothiazide and Atenolol individually and few methods in combination with other drugs. However, no stability indicating HPLC has been reported for simultaneous determination of Amlodipine Besylate, Hydrochlorothiazide and Atenolol in combination. In the proposed study an attempt will be made to develop a stability indicating HPLC method for simultaneous estimation of Simultaneous estimation of amlodipine, atenolol and hydrochlorothiazide in bulk and tablet dosage form by RP-HPLC Method G.Kumaraswamy*, N.Ravindra and K.B.Pradeesha Department of Pharmaceutical Analysis, Chilkur Balaji College of Pharmacy, Aziz Nagar –Hyderabad. 500075, Telangana. ABSTRACT A simple, accurate, rapid and precise isocratic reversed-phase high-performance liquid chromatographic method has been developed and validated for simultaneous determination of Amlodipine, Atenolol and Hydrochlorothiazide in capsules. The chromatographic separation was carried out on an cosmosil packed column 5C18-MS-I I analytical column (250×4.6 mm; 5 m) with a mixture of Phosphate buffer:Acetonitrile:Methanol pH 6 adjusted with Ortho phosphoric acid (30:20:50, v/v) as mobile phase; at a flow rate of 1 ml/min. UV detection was performed at 240nm. The retention times were 2.637, 3.148 and 8.492min. for Hydrochlorothiazide, Atenolol and Amlodipine respectively. Calibration plots e linear (r 2 >0.998) over the concentration range 2-12μg/ml for Amlodipine , 10-60g/ml Atenolol and 2-12μg/ml for Hydrochlorothiazide. The method was validated for accuracy, precision, specificity, linearity, and sensitivity. The proposed method was successfully used for quantitative analysis of capsules. No interference from any component of pharmaceutical dosage form was observed. Validation studies revealed that method is specific, rapid, reliable, and reproducible. The high recovery and low relative standard deviation confirm the suitability of the method for routine determination of Hydrochlorothiazide, Amlodipine and Atenolol in bulk drug and capsule dosage form. © 2015 Elixir All rights reserved. ARTICLE INFO Article history: Received: 6 September 2014; Received in revised form: 15 February 2015; Accepted: 24 February 2015; Keywords Hydrochlorothiazide, Amlodipine, Atenolol, HPLC. Elixir Pharmacy 79 (2015) 30637-30641 Pharmacy Available online at www.elixirpublishers.com (Elixir International Journal) Tele: E-mail addresses: kumaraswamy.gandla@gmail.com © 2015 Elixir All rights reserved