Formulation and In Vitro Evaluation of Solid Lipid Microparticles of Candesartan Cilexetil Floating Tablets

High blood pressure (HBP) is a serious condition that can lead to coronary heart disease, stroke, kidney failure and other health problems. Management of HBP with the conventional dosage forms of the existing antihypertensive agents are challenging to the clinicians. Candesartan cilexetil (CC) is a newer class of antihypertensive agent which comes under angiotensin II receptor antagonist. The current commercial formulation of CC is an immediate release and is administered twice daily. However, CC exhibited low oral bioavailability (only 15%) due to its poor aqueous solubility. Therefore, in the present study our aim was to formulate controlled release floating tablets of CC to minimize the untoward effects, patient compliance and improve the drug bioavailability. Fusion technique was used to formulate the drug and excipients into solid lipid microparticles (SLMs), which were then formulated as floating tablets using ethylcellulose as a polymer, and sodium bicarbonate and citric acid were used as gas generating agent. The microparticles and floating tablets were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, scanning electron microscopy and x-ray diffractometry. The obtained solid lipid microparticles were spherical in shape with particle diameter ranging from 38 to 48 µm. No new peak was observed in the x-ray diffractogram, suggesting the absence of interaction between drug and excipients. Compared to other formulations (F1-F8), F5 showed maximum in vitro drug release of 96.19% for 24h. Thus, our results confirm that floating tablets of CC is a novel method of development to improve the bioavailability of the drug and hence the floating tablets of CC would be a new potential drug delivery for the treatment of HBP.