In vitro and in vivo evaluation of multilayered pastilles for chronotherapeutic management of nocturnal asthma.

OBJECTIVE: The present work was undertaken with an objective to design a multilayered dosage form of doxofylline, using pastillation technology, for the chronotherapeutic management of nocturnal asthma. RESEARCH DESIGN & METHODS: Pastilles consisting of the drug, polyethylene glycol and colloidal silicon dioxide, were generated using an in-house laboratory-scale pastillation device. The pastilles were further coated with enteric polymers and a floating layer, using conventional coater. The pastilles were subjected to physicochemical analysis, morphological characterization, in vitro drug release studies and in vivo pharmacokinetic studies in rats. RESULTS: It was observed that colloidal silicon dioxide was instrumental in improving the contact angle of the pastilles. The uncoated pastilles released the drug immediately, while the enteric-coated (10% w/w) pastilles were found to have sufficient acid resistance when the coat is applied with 5% (v/v) triethyl citrate as plasticizer. The in vivo blood serum profile indicated that the pastilles coated with the enteric coat and the additional floating coat were effective in significantly delaying the in vivo drug release required for the chronotherapeutic treatment of nocturnal asthma. CONCLUSION: The present work opens a new alternative to the conventional tablet or capsule dosage form for the development of both immediate-release and modified-release drug delivery systems.

Berberine: a potential phytochemical with multispectrum therapeutic activities.

IMPORTANCE OF THE FIELD: The use of traditional medicines of natural origin is being encouraged for the treatment of chronic disorders, as synthetic drugs in such cases may cause unpredictable adverse effects. Berberine, a traditional plant alkaloid, is used in Ayurvedic and Chinese medicine for its antimicrobial and antiprotozoal properties. Interestingly, current clinical research on berberine has revealed its various pharmacological properties and multi-spectrum therapeutic applications. AREAS COVERED IN THIS REVIEW: An extensive search in three electronic databases (Unbound Medline, PubMed and ScienceDirect) and internet search engines (Scirus and Google Scholar) were used to identify the clinical studies on berberine, without any time constraints. This review elaborates the recent studies which reveal that with time, the drug has evolved with superior therapeutic activities. In addition, this review will also attract the attention of formulation scientists towards the issues and challenges associated in its drug delivery and the probable approaches that may be explored to help patients reap the maximum benefit of this potentially useful drug. WHAT THE READER WILL GAIN: A relatively large number of studies discussed here have revealed the possible areas where this phytochemical constituent can exhibit its therapeutic activities in the treatment of chronic ailments or diseases including diabetes, cancer, depression, hypertension and hypercholesterolemia. TAKE HOME MESSAGE: The potential of the drug remains to be harvested by designing a suitable formulation that could overcome its inherent low bioavailability.