The objective of this study is to synthesize and evaluate acute toxicity of the bacterial cellulose (BC)/acrylamide (Am) hydrogels as noncytotoxic and biocompatible oral drug delivery vehicles. A novel series of solubilized BC/Am hydrogels were synthesized using a microwave irradiation method. The hydrogels were characterized by Fourier transform infrared spectroscopy (FTIR), swelling ratio, porosity, drug release, and in vitro and in vivo biocompatibility experiments. FTIR spectra revealed that the BC crystallinity and gel fraction decreased as the NaOH concentration increased from 2% to 10% w/v, whereas the optical transparency, pH sensitivity, and porosity were enhanced with increasing alkali concentration. Theophylline was used as a model drug for drug loading and release studies. The percentage of drug released was higher at pH 7.4 compared to pH 1.5. In vitro cytotoxicity and hemolytic tests indicated that the BC/Am hydrogel is noncytotoxic and hemocompatible. Results of acute oral toxicity tests on ICR mice suggested that the hydrogels are nontoxic up to 2000 mg/kg when administered orally, as no toxic response or histopathological changes were observed in comparison to control mice. The results of this study demonstrated that the pH-sensitive smart hydrogel makes it a possible safe carrier for oral drug delivery.
Inhalation therapy of lipid-based carriers has great potential in direct target towards the root of respiratory diseases, which make them superior over other drug deliveries. With the successful entry of lipid carriers into the target cells, drugs can be absorbed in a sustained release manner and yield extended medicinal effects. Nevertheless, translation of inhalation therapy from laboratory to clinic especially in drug delivery remains a key challenge to the formulators. An ideal drug vehicle should safeguard the drugs from any premature elimination, facilitate cellular uptake, and promote maximum drug absorption with negligible toxicity. Despite knowing that lung treatment can be done via systemic delivery, pulmonary administration is capable of enhancing drug retention within the lungs, while minimizing systemic toxicity with local targeting. Current inhalation therapy of lipid-based carriers can be administered either intratracheally or intranasally to reach deep lung. However, the complex dimensions of lung architectural and natural defense mechanism poise major barriers towards targeted pulmonary delivery. Delivery systems have to be engineered in a way to tackle various diseases according to their biological conditions. This review highlights on the developmental considerations of lipid-based delivery systems cater for the pulmonary intervention of different lung illnesses.