Formulation and Evaluation of Liquid Self Micro Emulsifying Drug Delivery System of Trimipramine Maleate to Enhance Aqueous Solubility

Present research work was aimed to enhance aqueous solubility and dissolution rate of Trimipramine maleate by self micro emulsifying drug delivery system(SMEDDS), 40% of drugs in market are lipophilic having poor aqueous solubility and oral bioavailability with reduced dissolution rate, SMEDDS is a novel approach for enhancement of aqueous solubility, bioavailability and dissolution rate. Trimipramine maleate is a BCS class II drug having 65% oral bioavailability; it is used in the treatment of depression. Oils, Surfactants, Co surfactants were selected depending upon the saturated solubility of Trimipramine maleate in those components; excipients were screened depending on Trimipramine maleate solubility in various oils, surfactants and co surfactants. Surfactant: co surfactant {Smix} ratios i.e., 1:4 and 4:1 were prepared to determine micro emulsion regions and also to formulate liquid self micro emulsifying drug delivery system (L-SMEDDS). Pseudo ternary phase diagram were plotted by using Triplot version 4.1.2 software, micro emulsion region was determined and evaluated. Formulations were designed based on saturated solubility of Trimipramine maleate and Pseudo ternary phase diagram using various ratios of oils [Capryol 90], surfactants [Labrasol], co surfactants [Transcutol] depending on its solubility and micro emulsion formation two formulations were developed which are further selected for characterisation of L-SMEDDS like thermodynamic stability studies , self emulsification, determination of droplet size, PDI, zeta potential and also Invitro drug release. Among those two formulations, F1 (CL1T4 2:8) was optimum because compared to F2 (CL4T1 1:9) formulation F1 gave best results in terms of droplet size (250.3 d.nm) with PDI (0.390). The results of present study demonstrates that Trimipramine maleate SMEDDS has an ability and potential to enhance solubility and dissolution rate.