title: Effect of Rheology and Poloxamers Properties on Release of Drugs from Silicon Dioxide Gel-Filled Hard Gelatin Capsules-A Further Enhancement of Viability of Liquid Semisolid Matrix Technology.
abstract: The liquid and semisolid matrix technology, filling liquids, semi-solids and gels in hard gelatin capsule are promising, thus, there is a need of enhanced research interest in the technology. Therefore, the present study was aimed to investigate isoniazid (freely soluble) and metronidazole (slightly soluble) gels filled in hard gelatin capsules for the effect of poloxamers of different viscosities on release of the drugs. Gel of each drug (10% w/w, particle size 180-250 μm), prepared by mixing poloxamer and 8% w/w hydrophilic silicon dioxide (Aerosil® A200), was assessed for rheology, dispersion stability and release profile. Both the drugs remained dispersed in majority of gels for more than 30 days, and dispersions were depended on gels' viscosity, which was further depended on viscosity of poloxamers. A small change in viscosity was noted in gels on storage. FTIR spectra indicated no interactions between components of the gels. The gels exhibited thixotropic and shear-thinning behaviour, which were suitable for filling in hard gelatin capsules without any leakage from the capsules. The release of both drugs from the phase-stable gels for 30 days followed first-order kinetics and was found to be correlated to drugs' solubility, poloxamers' viscosity, polyoxyethylene contents and proportion of block copolymer (poloxamers) in the gels. The findings of the present study indicated that release of drugs of different solubilities (isoniazid and metronidazole) might be modified from gels using different poloxamers and Aerosil® A200.
authors.affiliation: Punjab University College of Pharmacy, University of the Punjab, Allama Iqbal Campus, Lahore, 54000, Pakistan.
authors.forename: Misbah
authors.initials: M
authors.lastname: Sultana
authors.affiliation: Punjab University College of Pharmacy, University of the Punjab, Allama Iqbal Campus, Lahore, 54000, Pakistan.
authors.forename: Mobashar Ahmad
authors.initials: MA
authors.lastname: Butt
authors.affiliation: Punjab University College of Pharmacy, University of the Punjab, Allama Iqbal Campus, Lahore, 54000, Pakistan.
authors.forename: Tariq
authors.initials: T
authors.lastname: Saeed
authors.affiliation: Highnoon Laboratory, Multan Road, Lahore, Pakistan.
authors.forename: Rizwan
authors.initials: R
authors.lastname: Mahmood
authors.affiliation: Faculty of Pharmacy, University of Lahore, Lahore, Pakistan.
authors.forename: Saeed
authors.initials: S
authors.lastname: Ul Hassan
authors.affiliation: Punjab University College of Pharmacy, University of the Punjab, Allama Iqbal Campus, Lahore, 54000, Pakistan.
authors.forename: Khalid
authors.initials: K
authors.lastname: Hussain
authors.affiliation: Punjab University College of Pharmacy, University of the Punjab, Allama Iqbal Campus, Lahore, 54000, Pakistan.
authors.forename: Syed Atif
authors.initials: SA
authors.lastname: Raza
authors.affiliation: Punjab University College of Pharmacy, University of the Punjab, Allama Iqbal Campus, Lahore, 54000, Pakistan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Ahsan
authors.affiliation: Punjab University College of Pharmacy, University of the Punjab, Allama Iqbal Campus, Lahore, 54000, Pakistan. nadeem_irfan@hotmail.com.
authors.forename: Nadeem Irfan
authors.identifier: http://orcid.org/0000-0001-5710-9574
authors.initials: NI
authors.lastname: Bukhari
mesh_terms: D002214:Capsules; D005780:Gelatin / Q000737:chemistry / Q000493:pharmacokinetics*; D005782:Gels; D010316:Particle Size; D020442:Poloxamer / Q000737:chemistry / Q000493:pharmacokinetics*; D012212:Rheology / Q000379:methods*; D012822:Silicon Dioxide / Q000737:chemistry / Q000493:pharmacokinetics*; D012995:Solubility; D014783:Viscosity
chemical_list: D002214:Capsules; D005782:Gels; D020442:Poloxamer; D012822:Silicon Dioxide; D005780:Gelatin
keywords: Aerosil 200; isoniazid; liquid semisolid matrix; metronidazole; poloxamer; rheology; thixotropy