%0 Journal Article
%T Preparation and Characterization of Liquisolid Compacts for Improved Dissolution of Telmisartan
%A Naveen Chella
%A Nataraj Narra
%A Tadikonda Rama Rao
%J Journal of Drug Delivery
%D 2014
%I Hindawi Publishing Corporation
%R 10.1155/2014/692793
%X The objective of the present work was to obtain pH independent and improved dissolution profile for a poorly soluble drug, telmisartan using liquisolid compacts. Liquisolid compacts were prepared using Transcutol HP as vehicle, Avicel PH102 as carrier, and Aerosil 200 as a coating material. The formulations were evaluated for drug excipient interactions, change in crystallinity of drug, flow properties, and general quality control tests of tablets using Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), X-ray diffraction (XRD), angle of repose, and various pharmacopoeial tests. In vitro dissolution studies were performed at three pH conditions (1.2, 4.5 and 7.4). Stability studies were performed at 40¡ãC and 75% RH for three months. The formulation was found to comply with Indian pharmacopoeial limits for tablets. FTIR studies confirmed no interaction between drug and excipients. XRD and DSC studies indicate change/reduction in crystallinity of drug. Dissolution media were selected based on the solubility studies. The optimized formulation showed pH independent release profile with significant improvement in dissolution compared to plain drug and conventional marketed formulation. No significant difference was seen in the tablet properties, and drug release profile after storage for 3 months. 1. Introduction Recent developments in combinatorial chemistry and high-throughput screening used in drug discovery resulted in increased number of drugs with poor aqueous solubility. Approximately 90% of the new chemical entities (NCEs) are considered poorly soluble with either high or low permeability (Biopharmaceutics Classification System (BCS) class II and IV) [1]. BCS class II drugs have high absorption number and low dissolution number. The absorption/bioavailability is limited by dissolution rate. These drugs exhibit varying bioavailability and small increment in dissolution may result in substantial improvement in bioavailability. Hence, dissolution enhancement is the key factor in formulating BCS class II drugs [2]. Telmisartan, 4¡ä-[(1,4¡ä-dimethyl-2¡ä-propyl[2,6¡ä-bi-1H-benzimidazol]-1¡ä-yl)methyl][1,1¡ä-biphenyl]-2-carboxylic acid, is a potent and selective AT1 receptor antagonist used in the treatment of essential hypertension [3]. Telmisartan is a BCS class II drug (aqueous solubility is 0.09£¿¦Ìg/mL) [4] with pH-dependent solubility (practically insoluble in the range of pH 3¨C9) and is highly hydrophobic in nature (log ; n-octanol/buffer at pH 7.4) [5]. Preclinical studies on telmisartan pharmacokinetics also report
%U http://www.hindawi.com/journals/jdd/2014/692793/