ABSTRACT
The aim of the study presented is to formulate and evaluate Acarbose controlled release matrix tablets by means of different grades of polymer Ethocel and different co-excipients with the intention to see their effects on drug release profile during in vitro dissolution studies. Controlled release dosage forms is gaining rapid popularity due to its positive aspect of reduction in dosage frequency and curtailing side effects. Controlled released tablets of Acarbose were prepared by direct compression method, using Ethocel[registered sign] Standard 7 Premium and Ethocel[registered sign] Standard 7 FP premium polymer. The effect of co-excipients including hydroxypropyl methylcellulose [HPMC], Carboxymethyl cellulose [CMC] and starch on the drug placing 30% lactose were also examined. In-vitro studies were carried out with the help of phosphate buffer [PH 7.4] as dissolution medium. Drug release mechanism was assessed by applying various kinetic models. Similarly / dissimilarity factor f[2]/ f[1] were applied for determination of dissolution profile of the test and reference formulations. Physiochemical characteristics were in the USP satisfactory limits. Conventional Acarbose tablet released 97% of the drug within 2 hrs. Ethocel[registered sign] Standard 7 premium and Ethocel[registered sign] standard 7 FP released 59.9% and 47.01% of the drug within 6 and 99.9% and 97% within 24 hours, respectively. This effect possibly has been aceived owing to the smaller particle size of the Ethocel[registered sign] Standard 7 FP premium which show evidence of anomalous, nonfickian release kinetics. Co-excipients like HPMC, CMC and starch augment the drug release rates from the matrices which may be attributed to their hydrophilic nature. Ethocel[registered sign] Standard 7 Premium and Ethocel[registered sign] Standard premium 7 FP polymers show a promising response in fruitful production of controlled release tablets by direct compression method
ABSTRACT
A UPLC-ESIMS method was developed for simultaneous analysis of seven major bioactive flavonolignans in silymarin including silychristins A(1) and B(2), silydianin(3), silybins A(4) and B(5), and isosilybins A(6) and B(7). In this study, the seven major active flavonolignans including the diastereomers 1/2, 4/5, and 6/7 were completely separated using UPLC with an ACQUITY UPLC C18 column and MeOH-water (formic acid) mobile phase system. The collision-induced dissociation (CID) MS/MS spectra of these flavonolignans were studied systematically using ESI-MS. The results with the present methodology showed that UPLC-MS/MS can be used for general screening of active natural products from plant extracts and for the specific quality control of silymarin.