Formulation and Evaluation of Nasal In Situ Gel for Cyproheptadine HCl

The main aim of the formulation was to prepare Nasal in situ gel for cyproheptadine HCl using an admixture of pH sensitive polymer i.e. carbopol 940 and viscosifying agent i.e. HPMC K100 M in order to achieve a sustained release of drug. The Nasal in situ gel containing cyproheptadine HCl was prepared by taking carbopol 940 and HPMC K100 M in different ratios. The concentrations of carbopol 940 and HPMC K100 M were investigated using 32 full factorial design. The parameters determined were pH, physical appearance, drug content, gelling capacity, Mucoadhesive strength, viscosity, in vitro drug release. The drug excipient compatibility study was carried out by using Fourier transform infrared spectroscopy(FTIR). The pH values in situ gels were between 5.0 to 6.0. Drug content values were between 98% to 100%. The release profile of in situ gels exhibited a sustained release of cyproheptadine HCl. Drug release was dependent on the concentration of carbopol 940 and concentration of HPMC K100 M. Cyproheptadine HCl was successfully formulated as an nasal in situ gel to deliver drug for 8 h. The drug release of the nasal in situ gel decreased with decrease in concentration carbopol 940 and viscosity increased with increasing levels of HPMC K100 M. The drug release and viscosity could be adjusted and modified by varying the ratio of polymer and viscosifying agent. The optimized formulation F8 (0.6 % w/v carbopol 940 and 0.4 % w/v of HPMC K100 M) provide drug release of 8 h and release drug immediately after it is instilled into the nose. Formulation F8 was seen to be stable after one month of stability study.