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Theophylline (TF) was preferably used for the treatment of asthma and chronic obstructive pulmonary diseases. However, it has a limited therapeutic range. So the controlled release of theophylline is required. In this study, TF was encapsulated with poly (vinyl alcohol) (PVA) and sodium carboxy methyl cellulose (NaCMC) polymers by using ionic gelation and liquid ripening method and iron III chloride (FeCl3) was used as crosslinking agent. Prepared microspheres were characterized and also defined by equilibrium swelling values and release profiles. Microspheres, in which the most suitable release conditions were determined, coated with EC and drug release studies were carried out. [ABSTRACT FROM AUTHOR]

Starch is a natural polymer that is among the sustainable materials and has the characteristics of being a green material in harmony with nature. In this study, a potential transdermal release system was evaluated by investigating 5‐fluorouracil (5‐FU) transfer through starch/poly(vinyl alcohol) (PVA) membranes in vitro. The effects of membrane thickness, starch/PVA blending ratio, pH, and temperature on the release of 5‐FU from the membranes were studied. At the end of the study, it was deduced that decrease in pH reduces the released amount of 5‐FU from starch/PVA membranes and 5‐FU transfer from membranes could be controlled within a fairly constant range. The diffusion coefficient was determined as 4.84× 10−3, 4.49× 10−3 and 2.54× 10−3 cm2 s−1 for the pH of 7.4, 5.5, and 3.5, respectively. The activation energy for the permeation 5‐FU from starch/PVA membrane (60/40, v/v) was found to be 9.72 kJ mol−1. [ABSTRACT FROM AUTHOR]

In this study, we aimed to produce pH-sensitive microspheres for the controlled release of the nonsteroidal anti-inflammatory drug, ketorolac tromethamine (KT). For this purpose, an interpenetrating polymer network (IPN) of microspheres of poly(vinyl alcohol) (PVA)/sodium carboxymethyl cellulose (NaCMC) were prepared, based on different formulations using glutaraldehyde (GA) (0.66 M) and hydrochloric acid (HCl) (3%, v/v). The preparation conditions of the microspheres were optimized by considering the percentage of entrapment efficiency and swelling capacity of the microspheres, and their release data. The effects of PVA and NaCMC ratio on the release of KT for over a period of 6 h, at three pH values (1.2, 6.8, and 7.4), have been discussed. [ABSTRACT FROM AUTHOR]