Oral self emulsifying powder of lercanidipine hydrochloride: Formulation and evaluation Venkata Raman Kallakunta, Suresh Bandari ⁎, Raju Jukanti, Prabhakar Reddy Veerareddy Department of Pharmaceutics and Industrial Pharmacy, St. Peter's Institute of Pharmaceutical Sciences, Warangal-506001, Andhra Pradesh, India abstract article info Article history: Received 30 April 2011 Received in revised form 20 January 2012 Accepted 21 January 2012 Available online 28 January 2012 Keywords: Self emulsifying powder Solubility Ternary phase diagram Dissolution efficiency Neusilin The current investigation was aimed to improve the solubility of poorly soluble lercanidipine hydrochloride as self emulsifying powder (SEP). Liquid SEDDS of LCH was formulated with Capmul MCM L8 as oil, Tween (R) 80 as surfactant and PEG 400 as co surfactant after screening various vehicles. The prepared formulations were evaluated for self emulsifying ability and phase diagram was constructed to optimize the system. These systems were further characterized for globule size, effect of pH and robustness to dilution, cloud point, ther- modynamic stability, surface morphology and drug release. The system was robust to different pH media and dilution volumes. The optimized system possessed a mean globule size of 169 ± 06 nm and cloud point of 76 °C. The self emulsifying powder was prepared by adsorbing the liquid SEDDS on to neusilin as carrier. The SEP formulated was free flowing with similar emulsification characteristics as that of liquid SEDDS. The X-ray diffraction, Differential Scanning Calorimetric studies of SEP revealed transformation of crystalline structure of LCH because of its molecularly dissolved state in the liquid SEDDS. This was further confirmed by scanning electron microscopy. High dissolution efficiency value of SEP compared with pure drug indicated the increase in dissolution characteristics of LCH in SEP. © 2012 Elsevier B.V. All rights reserved. 1. Introduction Most of the new chemical entities and existing drug candidates display low water solubility, which leads to poor bioavailability, high intrasubject/intersubject variability and lack of dose proportion- ality [1]. Thus the oral delivery of these low soluble drugs is hindered where dissolution is rate limiting step [2]. The various strategies such as solid dispersions [3], complexation with cyclodextrin [4], lipid- based formulations [5] and self emulsifying drug delivery systems (SEDDS) [6] have been reported in literature. Of various strategies reported self emulsifying drug delivery systems are found to be the prominent approach to improve solubility. Self-emulsifying drug delivery systems (SEDDS) improve the oral bioavailability of poorly soluble drugs by improving the solubility and maintaining the drug in a dissolved state, in small droplets of oil, all over its transit through the gastrointestinal tract [7]. SEDDS is an isotropic mixture of oils and surfactants that has the ability to form fine oil in water (o/w) emulsions or micro emulsions upon gen- tle agitation following dilution with the aqueous phase. Thus SEDDS disperse drug in gastric fluids of the stomach and presents the drug in small droplets of oil (b 5 μm) and improves drug dissolution by providing a large interfacial area for partitioning of the drug between the oil and aqueous gastro intestinal fluids [8]. However the traditional SEDDS as liquid dosage forms has limita- tions such as low drug loading capacity, drug leakage, low stability, few choices of dosage forms, excipient-capsule incompatibility and possibility of irreversible drugs/excipients precipitation[9]. To over- come these complications the liquid SEDDS are adsorbed on to inert carriers to produce solid SEDDS. This approach of solid SEDDS has advantages like stability, facility of manufacturing process, accuracy and patient compliance. Thus incorporation of liquid SEDDS into solid dosage forms combines the advantages of lipid based drug deliv- ery systems with those of solid dosage forms. Lercanidipine hydrochloride (LCH) a highly lipophilic calcium channel antagonist used in treatment of hypertension. The oral bio- availability of LCH is approximately 10% and shows erratic absorption from gastrointestinal tract which is attributed due to extensive first pass metabolism and low solubility [10]. In general limited investigations are reported to prepare solid SEDDS from liquid SEDDS. In the current study we developed liquid SEDDS with Capmul MCM L8 as oil, Tween (R) 80 as surfactant and PEG 400 as co surfactant. The prepared liquid SEDDS were formulated in to solid SEDDS as self emulsifying powder (SEP) by adsorbing on to powder Neusilin as carrier. Powder Technology 221 (2012) 375–382 ⁎ Corresponding author. Tel.: + 91 870 2567303; fax: + 91 870 2567304. E-mail address: reachbandari@gmail.com (S. Bandari). 0032-5910/$ – see front matter © 2012 Elsevier B.V. All rights reserved. doi:10.1016/j.powtec.2012.01.032 Contents lists available at SciVerse ScienceDirect Powder Technology journal homepage: www.elsevier.com/locate/powtec