Abstract:

Lisinopril is a potent ACE (angiotensin-converting enzyme) inhibitor used to treat hypertension and congestive heart failure. It exhibits 25% of low bioavailability. Hence, in the current study, the major objective was to increase the gastric transient time of lisinopril and develop in situ gel formulation for better absorption and modulating release behavior of lisinopril. Different formulations of lisinopril were prepared by using gelling polymers such as Carboxymethyl cellulose (CMC), pectin, and calcium carbonate. Sodium citrate was used to prevent gelation outside the gastric environment. The formulation was studied using Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC) to interpret the interaction between drugsand polymers. For optimization of in situ gelling system 32 full factorial design was employed to study the effect of independent variables, the concentration of CMC (X1) and concentration of sodium alginate (X2), on the dependent variables viscosity, and % drug content. Formulation (F5) containing 1.25% of sodium alginate, and 0.75% of CMC showed good gelling ability. The composition F5 was optimized on the basis of viscosity (5.03 Pa.s), drug content (94.06±1.0%), and cumulative drug release (95±0.73%) at 12 h. Floating in situ gelling system improved bioavailability and gastric transit time of lisinopril. A stability study indicated the absence of any noticeable change in the formulation. Thus, in situ gel formulation is a promising approach for gastro-retentive sustained delivery of lisinopril. These results ensure that the developed system is an alternative to conventional drug delivery systems and can enhance patient compliance.

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