Design and evaluation of controlled drug delivery system of buspirone using inorganic layered clay mineral

A new formulation for controlled delivery of buspirone hydrochloride (BUH) incorporating montmorillonite (MMT) and Eudragit® L 100 55 has been proposed. This paper demonstrates the beneficial effect of MMT in achieving controlled delivery of buspirone. The intercalation of MMT and BUH were studied under different reaction conditions, e.g., time, temperature, pH, and the initial concentration of BUH. Adsorption of BUH on MMT was described by Langmuir equation. X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR), and thermal analysis indicated that BUH molecules were stabilized in the interlayer galleries of MMT. The prepared MMT–BUH composite was further compounded with Eudragit® L 100 55 (methacrylic acid copolymer). The release behavior of BUH from MMT–BUH and MMT–BUH/Eudragit® L 100 55 in vitro conditions using buffer media of pH 6.8 showed the controlled release of intercalated drugs from MMT–BUH composite. The presence of Eudragit® L 100 55 decreased the rate and amount of drug release. BUH release reached to 54% and 23–29% within 12 h from MMT–BUH and MMT–BUH/Eudragit® L 100 55 composite, respectively. Different mathematical models were used, among them the best fitting was found for parabolic diffusion and Elovich equation.