Formulation and evaluation of olanzapine matrix pellets for controlled release

Olanzapine is an antipsychotic used in treatment of schizophrenia. This research was carried out to design oral controlled release matrix pellets of water insoluble drug Olanzapine [OZ], using blend of Sodium Alginate [SA] and Glyceryl Palmito-Stearate [GPS] as matrix polymers, micro crystalline cellulose [MCC] as spheronizer enhancer and Sodium Lauryl Sulphate [SLS] as pore forming agent. OZ formulations were developed by the pelletization technique by drug loaded pellets and characterized with regard to the drug content, size distribution, Scanning Electron Microscopy [SEM], Differential Scanning Calorimetry [DSC], Fourier Transform Infrared Spectroscopy [FTIR] and X-ray Diffraction study [XRD]. Stability studies were carried out on the optimized formulation for a period of 90 days at 40 +/- 2°C and 75 +/- 5% relative humidity. The drug content was in the range of 93.34-98.12%. The mean particle size of the drug loaded pellets was in the range 1024 to 1087 micro m. SEM photographs and calculated sphericity factor confirmed that the prepared formulations were spherical in nature. The compatibility between drug and polymers in the drug loaded pellets was confirmed by DSC and FTIR studies. Stability studies indicated that pellets are stable. XRD patterns revealed the crystalline nature of the pure OZ. Loose surface crystal study indicated that crystalline OZ is present in all formulations and more clear in formulation F5. Drug release was controlled for more than 24 hrs and mechanism of the drug release followed by Fickian diffusion. It may be concluded that F5 is an ideal formulation for once a day administration

Encapsulation of theophylline into binary blend of ethylcellulose and eudragit microparticles: development, characterization and kinetic release

The objective of this study was to prepare and evaluate microparticles of Eudragit and Ethyl cellulose binary blend loaded with theophylline for controlled release. Microparticles were prepared by Phase separation method. The method is quite simple, rapid, and economical and does not imply the use of toxic organic solvents. Solid, discrete, reproducible free flowing microparticles were obtained. The yield of the microparticles was up to 92%. More than 85% of the isolated microparticles were of particle size range of 325 to 455 micro m. The obtained angle of repose,% carr's index and tapped density values were well within the limits, indicating that prepared microparticles had smooth surface, free flowing and good packing properties. Scanning Electron Microscopy photographs and calculated sphericity factor confirms that the prepared formulations are spherical in nature. Prepared microparticles were sTab. and compatible, as confirmed by DSC and FT-IR studies. The prepared formulations were quantitatively analyzed for the amount of encapsulated drug. It was observed that there is no significant release of the drug at gastric pH. The drug release was controlled more than 12 h. Intestinal drug release from microparticles was studied and compared with the release behavior of commercially available oral formulation Duralyn CR 400. The release kinetics followed different transport mechanisms

Effect of hydrophilic natural gums in formulation of oral-controlled release matrix tablets of propranolol hydrochloride

In order to develop a controlled delivery of highly water-soluble propranolol hydrochloride [PPHCl] using hydrophilic natural gums [xanthan gum [X] and locust bean gum [LBG]] as cost-effective, nontoxic, easily available. The granules of PPHCl were prepared by wet granulation method using a different ratios drug: gum ratios of X, LBG and XLBG[X and LBG in 1:1 ratios]. To increase the flowability and compressibility of the granules, and to prevent its adhesion to punch and die, magnesium stearate and talc were added to the granules in 1:2 ratios before punching. The tablets was analysed to determine hardness, friability,% assay and invitro release study was carried out. The release of PPHCl from a gelatinous swollen mass, which controls the diffusion of drug molecules through the polymeric material into aqueous medium. The XLBG matrices shows precise controlled release than the X and LBG matrices because of burst effect and fast release in case of X and LBG matrices respectively and there was no chemical interaction between drug and polymers in XLBG formulation as confirmed by FTIR studies. First pass effect of PPHCl can be avoided by these formulations. Matrices with XLBG show zero-order release via swelling, diffusion and relaxation mechanism. The XLBG matrices leads to more precise result than X and LBG alone by the utilization of synergistic interaction between two biopolymers and uniformity in the hydration layer in dissolution media. However, according to the similarity factor [f2] XLBG3 were the most similar formulation to Lol-SR as the reference standard

Encapsulation of theophylline in waxes/fat microspheres: preparation, characterization and release kinetics of microspheres

The objectives of the present study is to prepare waxes/Tat microspheres loaded with Theophylline, [TP] a well known xanthine bronchodilator, was entrapped into gastro-resistant, biodegradable waxes such as beeswax [BW], cetostearyl alcohol [CSA], spermaceti [SC] and fat cetyl alcohol [CA] microspheres using meltable emulsified dispersion cooling induced solidification technique utilizing wetting agents. Solid, discrete, reproducible free flowing microspheres were obtained converting the liquid drug droplets into solid materials. Prepared waxes/fat microspheres are spherical in shape, have smooth surfaces with free flowing and good packing properties, as evidenced by scanning electron microscope [SEM]. The microspheres were characterized for their particle size, micromeritic properties and encapsulation efficiency. Size of the obtained waxes/fat microspheres ranged between 115 to 850 micro m. Molecular level drug distribution and compatibility of the drug after encapsulation in the waxes/fat microspheres was confirmed by differential scanning calorimetry [DSC] and FT1R spectral studies. The prepared microspheres were analyzed quantitatively for the amount of encapsulated drug. Maximum yield was produced by TP loaded in beeswax [AT] and minimum amount of TP was encapsulated into cetyl alcohol [DT] microspheres. The release of drug was controlled for more than 8 hours. Intestinal discharge of TP from waxes/fat microspheres was studied and compared with the oral formulation of TP [Unieontin[R]-n-400]. Among all the systems studied, TP loaded in cetostearyl alcohol [BT] have shown fastest release whereas slowest release by TP loaded in spermaceti [CT]. The release kinetics followed different transport mechanisms. The release performance was greatly affected by the materials used in microspheres preparations, which allows maximum absorption in the intestine