Preparation and evaluation of valsartan by a novel semi-solid self-microemulsifying delivery system using Gelucire 44/14

Development of a Solid Supersaturable Micelle of Revaprazan for Improved Dissolution and Oral Bioavailability Using Box-Behnken Design

PURPOSE

To enhance the oral bioavailability of revaprazan (RVP), a novel solid, supersaturable micelle (SSuM) was developed.

METHODS

Surfactants and solid carriers were screened based on a solubility and a flowability test, respectively. Supersaturating agents, including Poloxamer 407 (P407), were screened. The SSuM was optimized using a Box-Behnken design with three independent variables, including Gelucire 44/14:Brij L4 (G44/BL4; X1) and the amounts of Florite PS-10 (FLO; X2) and Vivapur 105 (VP105; X3), and three response variables, ie, dissolution efficiency at 30 min (Y1), dissolution enhancing capacity (Y2), and Carr's index (Y3). The solid state property was evaluated, and a dissolution test was conducted. RVP, Revanex®, solid micelle (P407-free from the composition of SSuM), and SSuM were orally administrated to rats (RVP 20 mg equivalent/kg) for in vivo pharmacokinetic study.

RESULTS

G44 and BL4 showed great solubility, with a critical micelle concentration range of 119.2-333.0 μg/mL. P407 had an excellent supersaturating effect. FLO and VP105 were selected as solid carriers, with a critical solidifying ratio (g/mL) of 0.30 and 0.91, respectively. With optimized values of X1 (-0.41), X2 (0.31), and X3 (-0.78), RVP (200 mg)-containing SSuM consisting of G44 (253.8 mg), BL4 (106.2 mg), FLO (99.3 mg), VP105 (199.8 mg), and P407 (40 mg) was developed, resulting in Y1 (40.3%), Y2 (0.008), and Y3 (12.3%). RVP existed in an amorphous state in the optimized SSuM, and the SSuM formed a nanosized dispersion in the aqueous phase, with approximately 71.7% dissolution at 2 h. The optimized SSuM improved the relative bioavailability of RVP in rats by approximately 478%, 276%, and 161% compared to raw RVP, Revanex®, and solid micelle, respectively.

CONCLUSION

The optimized SSuM has great potential for the development of solidified formulations of poorly water-soluble drugs with improved oral absorption.

Preparation, evaluation, and in vitro release of chitosan-alginate tanshinone self-microemulsifying sustained-release microcapsules

OBJECTIVE

In this study we explore the method to prepare tanshinone self-microemulsifying sustained-release microcapsules using tanshinone self-microemulsion as the core material, and chitosan and alginate as capsule materials.

METHODS

The optimal preparation technology of chitosan-alginate tanshinone self-microemulsifying sustained-release microcapsules was determined by using the orthogonal design experiment and single-factor analysis. The drug loading and entrapment rate were used as evaluation indexes to assess the quality of the drug, and the in vitro release rate was used to evaluate the drug release performance.

RESULTS

The best technology of chitosan-alginate tanshinone self-microemulsifying sustained-release microcapsules is as follows: the concentration of alginate is 1.5%, the ratio of tanshinone self-microemulsion volume to alginate volume to chitosan mass is 1:1:0.5 (ml: ml: g), and the best concentration of calcium chloride is 2.0%. To prepare the microcapsules using this technology, the drug loading will be 0.046%, the entrapment rate will be 80.23%, and the 24-hour in vitro cumulative release rate will be 97.4%.

CONCLUSION

The release of the microcapsules conforms to the Higuchi equation and the first-order drug release model and has a good sustained-release performance.

Amelioration of lipophilic compounds in regards to bioavailability as self-emulsifying drug delivery system (SEDDS)

Background

High lipophilicity and poor aqueous solubility are the endemic problems of new drug molecules. Sixty to seventy percent of these drugs are unable to solubilize completely in aqueous media, or have very low permeability. This hampers their oral absorption and further leads to their poor bioavailability. Various researches are in progress to overcome these limitations. Novel technologies like nano-carrier systems have become popular for improving the solubility of drugs.

Main body

Lipid-based formulations, among nano systems, are taking pace for the enhancement of solubility, oral absorption, and hence the bioavailability of drugs. Among the lipid formulations, self-emulsification systems are gaining popularity by offering various advantages to delivery systems. Self-emulsifying drug delivery systems (SEDDS) are isotropic blends of oil and surfactant/co-surfactants. These ingredients upon gentle agitation in aqueous media results in the formation of o/w emulsion. In spite of many works published in SEDDS, the major concerns of this article are to discuss the various approaches to formulate a good lipid-based carrier system for poorly aqueous soluble drugs, role of various polymers, and their categories used in the formulation along-with the modern technologies used for enhancing the stability of liquid SEDDS. This review majorly focuses upon the problems related to the poor aqueous solubility of the newer lipid molecules and the solutions to overcome their solubility and in addition bioavailability.

Conclusion

As per the researches done in formulation and optimization of SEDDS for the enhancement of bioavailability of lipophilic molecules, it can be stated that the aqueous solubility as well as bioavailability can be increased by many folds compared to their marketed or other oral formulations.

Quality by Design Enabled Development of Oral Self-Nanoemulsifying Drug Delivery System of a Novel Calcimimetic Cinacalcet HCl Using a Porous Carrier: In Vitro and In Vivo Characterisation

In this present research, work quality by design-enabled development of cinacalcet HCl (CH)-loaded solid self-nanoemulsifying drug delivery system (S-SNEDDS) was conducted using a porous carrier in order to achieve immediate drug release and better oral bioavailability. Capmul MCM (CAP), Tween 20 (TW 20) and Transcutol P (TRP) were selected as excipients. Cumulative % drug release at 30 min (Q30), emulsification times (ET), mean globule size (GS) and polydispersity index (PDI) were identified as critical quality attributes (CQAs). Factor mode effect analysis (FMEA) and Taguchi screening design were applied for screening of factors. The optimised single dose of S-SNEDDS obtained using Box-Behnken design (BBD) consisted of 30 mg of CH, 50 mg of CAP, 149.75 mg of TW 20, 55 mg of TRP and 260.75 mg of Neusilin US2. It showed an average Q30 of 97.6%, ET of 23.3 min, GS of 89.5 nm and PDI of 0.211. DSC, XRD and SEM predict the amorphous form of S-SNEDDS. In vivo pharmacokinetic study revealed better pharmacokinetic parameters of S-SNEDDS. The above study concluded that the optimised S-SNEDDS is effective to achieve the desired objective. Graphical Abstract.

Improved Dissolution and Oral Bioavailability of Valsartan Using a Solidified Supersaturable Self-Microemulsifying Drug Delivery System Containing Gelucire® 44/14

To improve the dissolution and oral bioavailability of valsartan (VST), we previously formulated a supersaturable self-microemulsifying drug delivery system (SuSMED) composed of Capmul^® MCM (oil), Tween^® 80 (surfactant), Transcutol^® P (cosurfactant), and Poloxamer 407 (precipitation inhibitor) but encountered a stability problem (Transcutol^® P-induced weight loss in storage) after solidification. In the present study, replacing Transcutol^® P with Gelucire^® 44/14 resulted in a novel SuSMED formulation, wherein the total amount of surfactant/cosurfactant was less than that of the previous formulation. Solidified SuSMED (S-SuSMED) granules were prepared by blending VST-containing SuSMED with selective solid carriers, L-HPC and Florite^® PS-10, wherein VST existed in an amorphous state. S-SuSMED tablets fabricated by direct compression with additional excipients were sufficiently stable in terms of drug content and impurity changes after 6 months of storage at accelerated conditions (40 ± 2 °C and 75 ± 5% relative humidity). Consequently, enhanced dissolution was obtained (pH 1.2, 2 h): 6-fold for S-SuSMED granules against raw VST; 2.3-fold for S-SuSMED tablets against Diovan^® (reference tablet). S-SuSMED tablets increased oral bioavailability in rats (10 mg/kg VST dose): approximately 177–198% versus raw VST and Diovan^®. Therefore, VST-loaded S-SuSMED formulations might be good candidates for practical development in the pharmaceutical industry.

Different types, applications and limits of enabling excipients of pharmaceutical dosage forms

Along with the development of novel drug delivery systems the material science is also advancing. Conventional and novel synthetic or natural excipients provide opportunities to design dosage forms of the required features including their bioavailability. Emerging trends in the design and development of drug products indicate an increasing need for the functionality-related characterization of excipients. The purpose of this review is to provide an overview of different types of excipients in relation to their application possibilities in various dosage forms with special focus on the enabling excipients. The study also summarizes the applied excipient systems of research formulations and dosage forms available on the market.

Enhanced oral bioavailability of valsartan using a polymer-based supersaturable self-microemulsifying drug delivery system

A novel, supersaturable self-microemulsifying drug delivery system (S-SMEDDS) was successfully formulated to enhance the dissolution and oral absorption of valsartan (VST), a poorly water-soluble drug, while reducing the total quantity for administration. Poloxamer 407 is a selectable, supersaturating agent for VST-containing SMEDDS composed of 10% Capmul® MCM, 45% Tween® 20, and 45% Transcutol® P. The amounts of SMEDDS and Poloxamer 407 were chosen as formulation variables for a 3-level factorial design. Further optimization was established by weighting different levels of importance on response variables for dissolution and total quantity, resulting in an optimal S-SMEDDS in large quantity (S-SMEDDS_LQ; 352 mg in total) and S-SMEDDS in reduced quantity (S-SMEDDS_RQ; 144.6 mg in total). Good agreement was observed between predicted and experimental values for response variables. Consequently, compared with VST powder or suspension and SMEDDS, both S-SMEDDS_LQ and S-SMEDDS_RQ showed excellent in vitro dissolution and in vivo oral bioavailability in rats. The magnitude of dissolution and absorption-enhancing capacities using quantity-based comparisons was in the order S-SMEDDS_RQ > S-SMEDDS_LQ > SMEDDS > VST powder or suspension. Thus, we concluded that, in terms of developing an effective SMEDDS preparation with minimal total quantity, S-SMEDDS_RQ is a promising candidate.