Drug Release In pH Research Articles

Thermal, mechanical and functional properties of cellulose acetate phthalate (CAP) coatings obtained from neutralized aqueous solutions

This study investigated the thermal, mechanical and functional properties of cellulose acetate phthalate (CAP) film coatings obtained from neutralized aqueous solutions. A novel salt forming agent, 2-amino-2-methyl-l-propanol (MAP), was used for the neutralization and dissolution of CAP in water. Triethylcitrate (TEC) was used as the plasticizer at 10–35% levels. Thermal and mechanical properties of free films plasticized with 10–35% TEC were evaluated by thermogravimetric analysis (TGA), thermal mechanical analysis (TMA) and dynamic mechanical spectroscopy (DMS). The physical stability of CAP/MAP films stored at 40 and 50°C was compared to ammoniated CAP films with respect to dissolution times in pH 6.8 buffer. Plasticized CAP/MAP films were also sprayed at three weight gains (6, 8 and 10%) onto acetylsalicylic acid (ASA) tablets (650 mg) using pan coating technology. The functional properties of the films were assessed for enteric integrity in 0.1 N HCI, drug release in pH 6.8 phosphate buffer and water permeability. Results have shown that CAP/MAP films plasticized with 25–35% TEC released ≤1% ASA after 2 h in 0.1 N HCl and > 95% after 1 h in buffer, thereby demonstrating their excellent functional properties. These films had high permeability to water/acid which makes them unsuitable for acid-labile drugs, since water/HCl would penetrate rapidly into the tablet core and degrade the drug. Neither the T g nor E′ values differed significantly for films that showed satisfactory functional properties. Films were stiff and brittle with E′ values in the range of 2–3 × 10 9 Pa and T g values of 108–112°C. TEC appeared to have limited solubility in the CAP/MAP polymer with reduced plasticization effects at concentrations higher than 20–25%. CAP/MAP free films were found to be superior to ammoniated CAP films with respect to extent of aging when stored at 40°C. The results clearly showed the potential use of plasticized CAP/MAP films as an enteric film former for pharmaceutical products.

Spray Dried Mucoadhesive Microspheres of Ondansetron for Nasal Administration

Systemic delivery of drugs via nasal route has many advantages for protein and peptide drug molecules as well as conventional molecules. Mucoadhesive drug delivery systems are those that provide intimate contact of the drug are those that provide intimate contact of the drug with the mucosa for an extended period of time. In this current work chitosan mucoadhesive microspheres of ondansetron HCL were prepared by spray-drying method, with an aim to avoid first pass effect and to improve therapeutic efficacy of Ondansetron in treatment of nauseas and vomiting. Preformulation studies were carried out in order to find out the drug excipient interaction in order to find out the drug excipients. I.R. spectrum and TLC method was used to find out the interaction between drug and excipient. Formulations were evaluated for physical characteristics such as particle size, incorporation efficiency, swelling ability in vitro bioadhesion and in vitro drug release in pH 6.6 phosphate buffer. Average particle size of microspheres was found to be in size of microspheres was found to be in size range 7-9 µm. All microspheres had good percentage of entrapment efficiency between 88% and 97% chitosan microspheres showed very good mucoadhesion due to electrostatic attraction between chitosan and mucin. The Fourier transformed infrared (FTIR) spectra obtained from various formulations of spray-dried microspheres showed no interaction within these formulations. The release of ondansetron hydrochloride from these microspheres was fast. These in vitro results show that spray-dried microspheres based on chitosan could be suitable nasal mucoadhesive delivery system for administration of ondansetron hydrochloride.