title: Investigating effects of hydroxypropyl methylcellulose (HPMC) molecular weight grades on lag time of press-coated ethylcellulose tablets.
abstract: The research undertaken exemplifies the effects of hydroxypropyl methylcellulose (HPMC) molecular weight (MW) grades of on lag time of press-coated ethylcellulose (EC) tablets. The formulation comprised an immediate release core (containing prednisone as a model drug) surrounded by compression coating with variegated EC-HPMC blends. Five selected HPMC grades (E5, E15, E50, K100LV and K4M) were explored at three different concentrations (10% w/w, 20% w/w and 30% w/w in outer coat) to understand their effects on lag time and drug release. In vitro drug release testing demonstrated that, with increase in concentration of E5 and E15, up to 30% w/w, the mean lag time decreased progressively; whereas with remaining grades, the mean lag time initially decreased up to 20% w/w level and thereafter increased for 30% w/w level. Importantly, with increase in HPMC concentration in the outer coat, the variability in lag time (%RSD; n = 6) was decreased for each of E5, E15 and E50, whereas increased for K100LV and K4M. In general, the variability in lag time was increased with increase in HPMC MW at studied concentration levels. Markedly, tablets with 30% w/w K4M in outer coat exhibited slight premature release (before the rupture of outer coat) along with high variability in lag time. Overall, the study concluded that low MW HPMCs (E5, E15 and E50) were found rather efficient than higher MW HPMCs for developing robust EC-based press-coated pulsatile release formulations where precise lag time followed by sharp burst release is desired.
authors.affiliation: a Pharmacy Department, Faculty of Technology and Engineering , The Maharaja Sayajirao University of Baroda , Kalabhavan, Vadodara , Gujarat , India.
authors.forename: Riddhish
authors.initials: R
authors.lastname: Patadia
authors.affiliation: a Pharmacy Department, Faculty of Technology and Engineering , The Maharaja Sayajirao University of Baroda , Kalabhavan, Vadodara , Gujarat , India.
authors.forename: Chintan
authors.initials: C
authors.lastname: Vora
authors.affiliation: a Pharmacy Department, Faculty of Technology and Engineering , The Maharaja Sayajirao University of Baroda , Kalabhavan, Vadodara , Gujarat , India.
authors.forename: Karan
authors.initials: K
authors.lastname: Mittal
authors.affiliation: a Pharmacy Department, Faculty of Technology and Engineering , The Maharaja Sayajirao University of Baroda , Kalabhavan, Vadodara , Gujarat , India.
authors.forename: Rajashree
authors.initials: R
authors.lastname: Mashru
mesh_terms: D002482:Cellulose / Q000031:analogs & derivatives* / Q000737:chemistry; D002626:Chemistry, Pharmaceutical / Q000379:methods; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D016503:Drug Delivery Systems / Q000379:methods; D005079:Excipients / Q000737:chemistry; D065347:Hypromellose Derivatives / Q000737:chemistry*; D008970:Molecular Weight; D012995:Solubility; D013607:Tablets / Q000737:chemistry*
chemical_list: D020099:Coated Materials, Biocompatible; D005079:Excipients; D013607:Tablets; D065347:Hypromellose Derivatives; C013517:ethyl cellulose; D002482:Cellulose
keywords: Chronotherapeutic; compression coating; excipient; pulsatile release; time-controlled formulation