@article { ISI:000266640800030,
	title = {Modulation and optimization of drug release from uncoated low density porous carrier based delivery system},
	journal = {AAPS Pharmscitech},
	volume = {10},
	number = {2},
	year = {2009},
	month = {JUN},
	pages = {547-558},
	publisher = {SPRINGER},
	address = {233 SPRING ST, NEW YORK, NY 10013 USA},
	abstract = {<p>The purpose of this research work was to explore an application of uncoated porous drug carrier prepared by single-step drug adsorption for a delivery system based on integration of floating and pulsatile principles intended for chronotherapy. This objective was achieved by utilizing 3(2) factorial design, solvent volume (X (1)) and drug amount (X (2)) as selected variables, for drug adsorption using solvents, methanol, and dichloromethane (DCM), of varying polarity. Nitrogen adsorption (N(2)), scanning electron microscopy of cross-sections, and atomic force microscopy were done to study adsorption patterns and their effect on release pattern. Drug release study was customized by performing for 6 h in acidic environment to mimic gastroretention followed by basic environment akin to transit phase. Correlation between porous data from mercury and N(2) adsorption was probably studied for the first time. Observed regression analysis values for pore volume, surface area, and drug release indicated the influence of selected variables. Total release range in acidic medium was 12.77-24.57\% for methanol, 8.79-15.26\% for DCM, and final release of 69.45-92.23\% for methanol, and 60.16-99.99\% for DCM influenced by varying internal geometries was observed. Present form of drug delivery system devoid of any additives/excipients influencing drug release shows distinct behavior from other approaches/technologies in chronotherapy by (a) observing desired low drug release (8\%) in acidic medium, (b) overcoming the limitations of process variables caused by multiple formulation steps and different characteristic polymers, (c) reducing time consumption due to single step process, and (d) extending as controlled/extended release.</p>},
	keywords = {chronotherapy, floating pulsatile drug delivery system, low density porous carrier, pore data, solvent polarity},
	issn = {1530-9932},
	doi = {10.1208/s12249-009-9239-9},
	author = {Sher, Praveen and Ingavle, Ganesh C. and Ponrathnam, Surendra and Poddar, Pankaj and Pawar, Atmaram P.}
}
@article { ISI:000273174300036,
	title = {Novel/conceptual floating pulsatile system using high internal phase emulsion based porous material intended for chronotherapy},
	journal = {AAPS Pharmscitech},
	volume = {10},
	number = {4},
	year = {2009},
	month = {DEC},
	pages = {1368-1380},
	publisher = {SPRINGER},
	address = {233 SPRING ST, NEW YORK, NY 10013 USA},
	abstract = {<p>The aim of the present study was to design a novel/conceptual delivery system using ibuprofen, anticipated for chronotherapy in arthritis with porous material to overcome the formulation limits (multiple steps, polymers, excipients) and to optimize drug loading for a desired release profile suitable for in vitro investigations. The objective of this delivery system lies in the availability of maximum drug amount for absorption in the wee hours as recommended. Drug loading using 3(2) factorial design on porous carrier, synthesized by high internal phase emulsion technique using styrene and divinylbenzene, was done via solvent evaporation using methanol and dichloromethane. The system was evaluated in vitro for drug loading, encapsulation efficiency, and surface characterization by scanning electron, atomic force microscopy, and customized drug release study. This study examined critical parameters such as solvent volume, drug amount, and solvent polarity on investigations related to drug adsorption and release mostly favoring low-polarity solvent dichloromethane. Overall release in all batches ranged 0.98-52\% in acidic medium and 71-94\% in basic medium. These results exhibit uniqueness in achieving the least drug release of 0.98\%, an ideal one, without using any release modifiers, making it distinct from other approaches/technologies for time and controlled release and for chronotherapy.</p>},
	keywords = {chronotherapy, floating pulsatile drug delivery system, high internal phase emulsion, ibuprofen, multiparticulate porous carriers},
	issn = {1530-9932},
	doi = {10.1208/s12249-009-9331-1},
	author = {Sher, Praveen and Ingavle, Ganesh C. and Ponrathnam, Surendra and Benson, James R. and Li, Nai-Hong and Pawar, Atmaram P.}
}
