| Indomethacin is a clinically important potent non-steroidal anti-inflammatory agent. Currently, it is marketed as a controlled release capsule in strength of 75 mg to provide several advantages over conventional dosage forms. Such drug administration reduces the frequency of dosage, the strength of the required dose, and number of side effects while increasing the effectiveness of the drug, improving patient compliance and providing a constant prolonged and uniform therapeutic effect.; Thousands of drug substances are marketed with varied physical, chemical and pharmacokinetic properties. It is imperative that formulators continue to use innovative techniques to improve upon the existing ways to develop these pharmaceutical dosage forms. Solid dispersion systems initially focused on producing increased dissolution rates and bioavailability of water insoluble drugs. Recent attempts have been aimed at achieving other goals such as sustained release of drugs, enhanced release of drugs and improved solubility and stability.; The main objective of the study was to explore the applications of solid dispersion technique to simplify the art of sustaining the drug release from solid dosage forms. Solid dispersions were prepared by solvent method, using formulations containing various ratios of drug and rate-controlling polymers. Drug release profiles were determined by the USP I rotating basket method.; Among all the formulations evaluated, the solid dispersion containing Drug/EudragitRTM RS PO (1:1.5 w/w) gave the desirable in-vitro drug dissolution profile over an extended period of time. In addition, when compared against the physical mixture of the same formulation, the results showed that the drug release was only controlled with the dispersion formulation. This attested to the fact that it was not the presence of rate-controlling materials in the formulation, but the formation of solid dispersion which sustained the drug release.; Another objective of this study was to evaluate the feasibility of solid dispersions to produce products of varied strengths using the same, single formulation. Varied strengths of 25 mg, 50 mg and 75 mg of solid dispersion powder from the same formulation were tested for their in-vitro dissolution profiles. The experimental data revealed that the percentage drug release and the drug release patterns were similar regardless of the dosage strength. This supports the fact that a single solid dispersion powder enables one to conveniently develop the multiple strength dosage forms of this drug.; In addition, the solid dispersion powder was evaluated for physical characteristics using Fourier Transform Infrared spectroscopy, X-ray diffraction, Differential Scanning Calorimetric studies. These studies supported that the drug exists in the amorphous form and there are no chemical interaction among the drug and polymeric materials. |
