Formulation and in Vitro Characterisation of Glipizide Loaded Mucoadhesive Gelatin Microspheres

The Present study an attempt was made to formulate glipizide loaded microspheres using Gelatin as a mucoadhesive polymer by emulsion cross linking method using 25%v/v glutaraldehyde as a cross linking agent for management of type 2 diabetes mellitus. The literature survey reveals that extensive research has been carried out on development of mucoadhesive microspheres containing anti-diabetic drug by various methods. It is noteworthy that there was no literature review available describing the formulation of glipizide loaded mucoadhesive microspheres prepared using Gelatin hence the study was further preceded. In formulations were prepared using gelatin as a polymer (1:20, 1:15, 1:10, 1:7.5, 1:5 and 1:2.5) in six different ratios. The effect of polymer as well as decreasing concentration of gelatin on microspheres was studied by subjecting all the formulations to various evaluation parameters. The FTIR study was carried out for the drug, polymer, physical mixture and optimized formulation in FTIR study, all characteristic peaks in the spectra appeared without any remarkable changes showing that there is no chemical interaction between the drug and polymer used in the preparation of microspheres. The mean particle size study was carried out by using microscopic analysis and found that the range for all formulations was varied from 525 to 792 μm due to change in drug and polymer ratio. The morphology of optimized formulation was studied by SEM analysis and found that shape of microspheres were spongy, discrete, almost spherical and found to be satisfactory. The drug content for all the formulations was found to be in the range of 81 to 87% w/w. The formulation F5 had the highest drug content of 87% w/w. The entrapment efficiency of all formulations was found to be in the range of 81 to 87.35%. The entrapment efficiency of formulation F5 was found to be higher. The drug loading was found to be in the range 3.58 to 17.5%.The formulation F5 had the maximum loading efficiency. The mucoadhesive microspheres of Glipizide were prepared by Emulsion cross linking method using natural polymer Gelatin utilizing temperature change and cross linking agent glutaraldehyde was able to sustain the drug release efficacy. By varying the drug: polymer concentration ratio, the drug release was sustained. The evaluation parameters like morphological analysis, drug content, entrapment efficiency, drug loading capacity, swelling ratio, in vitro mucoadhesion studies and invitro drug release studies was done for the microspheres and found to be satisfactory. The stability study results shows that the formulation F5 was stable at temperature 40 ± 2°C/75% RH at the end of 3 months. The comparative study with the marketed SR formulation results showed that the F5 microsphere formulation had a sustained and prolonged drug release at the end of 24 h than the marketed glipizide SR formulation. The results of the study revealed that the use of natural polymer Gelatin is an effective strategy for the designing and development of glipizide loaded mucoadhesive microspheres for easy, reproducible and effective oral controlled drug delivery for the treatment of type II Diabetes mellitus