Evaluation of Khaya gum (Khaya senegalensis) as a polymer in the formulation of floating in situ gels of metoprolol succinate

Metoprolol succinate, a β-selectiveadrenergic blocker, has a short half-life, low bioavailability, and high dosingfrequency. In-situ gel drug delivery is a good approach to achieve sustained release for once-daily administration thatwill prolong drugretention time at the stomach and increase absorption. Thus,the aim of the study is to formulate floatingin-situ gel formulations of metoprolol succinate using Khaya gum (Khayasenegalensis, family Meliaceae) as a polymer. Khaya gum wascharacterized and used in formulating in situ gels of metoprololsuccinate in comparison with Hydroxyl Propyl Methyl Cellulose (HPMC K15M) andXanthan gum. The in-situ gel formulations were characterized forappearance, swelling, in- vitro buoyancy and in-vitro drugrelease. FTIR revealed major peaks characteristic of the gum. Khaya gum showedhigh swelling and good flow properties. In-situ gel formulations of metoprolol succinatecontaining Khaya were light brown with near neutral pH, higher swelling and a total floating time >24 h,comparable to those containing HPMC and Xanthan gums. Dissolution time t80was 60.50 to >240 min with ranking Khaya <HPMC <Xanthan. Khaya gum providesa cheaper, suitable polymer for formulating floating in-situ gels with prolonged buoyancy and drug release.