Formulation and Evaluation of Lisinopril Double Layer Tablet

Lisinopril is an antihypertensive drug that is primarily used in the treatment of hypertension, congestive heart failure, heart attacks and also in preventing renal and retinal complication of diabetes that acts by inhibiting angiotension converting enzyme (ACE). The present investigation deals with the formulation of lisinopril double layer tablet containing 100 mg fast release layer and 100 mg sustained release layer to be formulated using wet granulation method. Twelve formulations are prepared for bilayered tablets; 6 formulas for fast release layer study (FF1 to FF6) and another 6 formulas for the sustained release layer study. Friability of all formulation was less than 1%, which indicates the tablets had good mechanical resistance. Drug content was found to be uniform in all formulas. The tablet thickness was found to be 5.12 to 5.31 mm. Acceptable weight variation and content uniformity. Hardness was low for fast release lisinopril layer formulas FF1 to FF6, while it was high for formulas used to study the sustained release layer (SF1 to SF6). On the other hand disintegration time was short for formulas containing super disintegrant as crospovidone 15, and 10 seconds, croscarmelose 27, and 24 seconds and sodium starch glycolate 24, and 19 seconds and the shortest time for disintegration was for crospovidone containing formulas (FF1, and FF4); 15, and 10 seconds respectively for fast release layer study with no disintegration for the formulas used to study the sustained release of lisinopril. At the same time the release study for formulas containing crospovidone was within 20 minutes, while formulas containing HPMC K100 was 12 hours release. To be concluded that double layer tablets were attempted to be prepared for controlled drug delivery. The first layer of lisinopril provides the initial drug release while the second layer provides sustained release of lisinopril for increase patient compliance and decrease frequency of dosing for more control of hyper tension.