The present study delineate the formulation of microemulsion composed of TX-100:AcOH(1:1), Chloroform, Water and to investigate its potential as drug delivery system for an antitubercular drug isoniazid. The pseudo-ternary phase diagram (Gibbs Triangle) were constructed for these systems with and without isoniazid. Microemulsion system showed the occurrence of structural changes from water-in-oil to oil-in-water microemulsion. It has been observed that the microemulsion remained stable after the incorporation of isoniazid. After dilution a controlled release of drug is expected from o/w emulsion droplet. Further to study the incorporation of drug in TX100 based microemulsion in presence of cetyl trimethyl ammonium dichromate (CTADC), a lipophylic oxidant, phase diagrams of systems containing TX-100:AcOH(1:1), Chloroform, CTADC, Water has been constructed in the presence and absence of isoniazid. The results suggested that isoniazid binds to the CTADC in o/w and w/o microemulsion. Thus drug release is possible where there is demand for the drug. The present TX 100 based microemulsion in presence of CTADC appears beneficial for the delivery of the isoniazid