Padala Narasimha Murthy

The present study aims at investigating the different combinations of polymers with inclusion complex of Carvedilol (CR)-Hydroxypropyl betacyclodextrin (HPβCD) prepared in a ratio of 1:1 by use of various analytical techniques like Fourier Transformation Infrared spectroscopy (FTIR), X-ray diffraction technique (XRD), Digital scanning calorimetry (DSC), Thermo gravimetric analysis (TGA) as a part of preformulation studies. Various polymers used for the present study were Sodium alginate (SA), Hydroxy propyl beta cyclodextrin (HPBCD), Hydroxy propyl methyl cellulose LV E-15(HPMC), Pectin (P), Eudragit NE30D (EU). This study indicated that Carvedilol formed inclusion complex with the HPβCD, but in combination with other polymers, drug did not show any other interactions.

In the present investigation, pH-dependent and controlled drug release polymeric microspheres of Ornidazole were developed to deliver the active molecule to the colonic region. Microspheres were prepared by emulsion cross-linking method with some modifications, using different proportions of Ornidazole and Polymers (guar gum and gelatin). Gelatin microspheres were coated with Acrycoat L100 to achieve pH sensitive properties and specific biodegradability for colon targeted delivery of Ornidazole. Microspheres were evaluated for size, morphology, sphericity study, % yield, loose surface crystal study, drug content and entrapment efficiency. In vitro drug release study was conducted by buffer change method to mimic GIT environment using buffer solutions of varying pH. The investigations revealed that microspheres prepared with Ornidazole: guar gum ratio (1:2) shows only 10.003±0.885 % drug was released in first 5 hours and 38.849 ± 0.62 % in 12 hours, which proves the potentiality of guar gum for colonic delivery of drugs. While for microspheres prepared with Ornidazole: gelatin (1:2) and coated with Arycoat L100 shows 16.596 ± 3.18 % drug release in first 5 hours and 45.921 ± 3.07 % in 12 hours. Key Words: colon specific drug delivery, biodegradable polymers, pH-dependent release, In vitro drug release