Processing a detergent powder formulation: Direct compression, and high shear wet granulation followed by compression

Hydrogel-based matrices for controlled drug delivery of etamsylate: Prediction of in-vivo plasma profiles

Objectives

To design oral controlled release (CR) hydrogel matrix tablets of etamsylate using various hydrophilic polymers. Additionally, to predict plasma concentration-time profiles of etamsylate released from different CR matrices.

Methods

Characterization of the in-vitro release rate was performed by various model dependent and model independent approaches. A simple numerical convolution strategy was adopted to predict the in-vivo performance of all matrices from their in-vitro percent released data. The statistical analysis was conducted utilizing a student t-test and ANOVA.

Results

The release of etamsylate from all matrices showed a deviation from Fickian transport mechanism except; F2 followed Case II release whereas, F9 and F11 obeyed Fickian diffusion. CR hydrogel based-matrices (F4 and F11) demonstrated the maximum drug retardation and satisfied the USP release limits. Concentration-time profiles of etamsylate were predicted successfully from the in-vitro release data of all prepared matrices. Pharmacokinetic parameters of etamsylate CR hydrogel matrices were significantly changed with comparison to reference product except F1.

Conclusion

The designed (F2-F11) matrices had the capability to extend the plasma level of etamsylate for an adequate time. However, F4 and F11 were considered the most ideal formulations for once daily application of etamsylate. The prediction of in-vivo pharmacokinetics of etamsylate was very useful to assess the rationality of the designed matrices for the practical application in humans.

Self-microemulsifying systems of Finasteride with enhanced oral bioavailability: multivariate statistical evaluation, characterization, spray-drying and in vivo studies in human volunteers

AIM

To develop Finasteride-loaded self micro-emulsifying drug delivery systems (SMEDDS) for the treatment of hormonal associated problems.

MATERIALS & METHODS

Ternary phase diagrams were constructed to obtain self-emulsification regions. Multivariate statistical methods viz. Principal component analysis and agglomerative hierarchy clustering analysis were used to evaluate the microemulsions stability. In vitro redispersibility study was adopted and two formulations were selected for spray-drying. Further investigations were performed (Fourier transform infrared, x-ray diffraction and transmission electron microscopy). Finally, the in vivo performance was tested in human volunteers.

RESULTS

Multivariate statistical methods selected stable SMEDDS. Spray-drying utilizing maltodextrin/leucin carrier system yielded a flowable product. Selected solid SMEDDS scored 129.35% relative bioavailability compared with a commercial tablet.

CONCLUSION

The developed SMEDDS poses successful platform for glucosteroid analogs oral delivery.

Two different approaches for the prediction of in vivo plasma concentration-time profile from in vitro release data of once daily formulations of diltiazem hydrochloride

The aim of this study was to employ two different mathematical approaches: first, a convolution approach using computer software; second, a mathematical calculation exploiting Wagner-Nelson calculation to predict in vivo plasma concentration-time profile from the in vitro release study for the once daily formulations of a model drug diltiazem hydrochloride. The once daily extended release tablets (120 mg) were prepared by the wet granulation technique. Ethanol or ethanolic solutions of ethylcellulose (N22), were used as granulating agents along with hydrophilic matrix polymers like hydroxypropyl methylcellulose (HPMC) (K 15M). The granules showed satisfactory flow properties, compressibility, moisture content and drug content. All the tablet formulations showed acceptable properties and complied with pharmacopeial limits. The in vitro drug release study revealed that formula F7-T which contains drug: HPMC ratio 1:1 and 20 mg of ethylcellulose was able to sustain the drug release for 24 h and satisfied the USP dissolution limits. Fitting the in vitro drug release data to Korsmeyer-Peppas equation indicated that the mechanism of drug release could be zero-order. The capsule formulation F14-C which consists of drug: HPMC ratio 1:2, 12 mg of ethylcellulose and 20 mg of polyox 100 showed in vitro drug release similar to the tablet F7-T using the similarity factor (f 2). The mechanism of drug release could be coupled diffusion, and polymer matrix relaxation. The percent dissolved data from the two formulations were used as input function to predict the in vivo plasma data by the two approaches (Convolution by Kinetica software and Wagner-Nelson calculation). The two methods were validated by prediction of plasma data from in vitro release data of FDA approved 300 mg extended release capsule. Prediction errors were estimated for Cmax and area under the curve (AUC) to determine the validity of the methods. The percent prediction error for each parameter is not exceeding 15%.

Preparation and evaluation of self-nanoemulsifying tablets of carvedilol

The purpose of this study was to combine the advantages of self-nanoemulsifying drug delivery systems and tablets as a conventional dosage form emphasizing the excipients' effect on the development of a new dosage form. Systems composed of HCO-40, Transcutol HP, and medium-chain triglyceride were prepared. Essential properties of the prepared systems regarding carvedilol solubility, a model drug, and self-emulsification time were determined. In order to optimize self-nanoemulsifying drug delivery systems (SNEDDS), formulation dispersion-drug precipitation test was performed in the absence and presence of cellulosic polymers. Furthermore, SNEDDS was loaded onto liquisolid powders. P-glycoprotein (P-gp) activity of the selected SNEDDS was tested using HCT-116 cells. Carvedilol showed acceptable solubility in the selected excipients. It also demonstrated improvement in the stability upon dilution with aqueous media in the presence of cellulosic polymers. Use of granulated silicon dioxide improved the physical properties of liquisolid powders containing SNEDDS. It improved the compressibility of the selected powders and the tested SNEDDS showed marked P-gp inhibition activity. Prepared self-nanoemulsifying tablet produced acceptable properties of immediate-release dosage forms and expected to increase the bioavailability of carvedilol.