Zero-order release and bioavailability enhancement of poorly water soluble Vinpocetine from self-nanoemulsifying osmotic pump tablet

SeDeM tool-driven full factorial design for osmotic drug delivery of tramadol HCl: Formulation development, physicochemical evaluation, and in-silico PBPK modeling for predictive pharmacokinetic evaluation using GastroPlus™

The study is based on using SeDeM expert system in developing controlled-release tramadol HCl osmotic tablets and its in-silico physiologically based pharmacokinetic (PBPK) modeling for in-vivo pharmacokinetic evaluation. A Quality by Design (QbD) based approach in developing SeDEM-driven full factorial osmotic drug delivery was applied. A 2⁴ Full-factorial design was used to make the trial formulations of tramadol HCl osmotic tablets using NaCl as osmogen, Methocel K4M as rate controlling polymer, and avicel pH 101 as diluent. The preformulation characteristics of formulations (F1-F16) were determined by applying SeDeM Expert Tool. The formulation was optimized followed by in-vivo predictive pharmacokinetic assessment using PBPK “ACAT” model of GastroPlus™. The FTIR results showed no interaction among the ingredients. The index of good compressibility (ICG) values of all trial formulation blends were ≥5, suggesting direct compression is the best-suited method. Formulation F3 and F4 were optimized based on drug release at 2, 10, and 16 h with a zero-order kinetic release (r² = 0.992 and 0.994). The SEM images confirmed micropores formation on the surface of the osmotic tablet after complete drug release. F3 and F4 were also stable (shelf life 29.41 and 23.46 months). The in vivo simulation of the pharmacokinetics of the PBPK in-silico model revealed excellent relative bioavailability of F3 and F4 with reference to tramadol HCl 50 mg IR formulations. The SeDeM expert tool was best utilized to evaluate the compression characteristics of selected formulation excipients and their blends for direct compression method in designing once-daily osmotically controlled-release tramadol HCl tablets. The in-silico GastroPlus™ PBPK modeling provided a thorough pharmacokinetic assessment of the optimized formulation as an alternative to tramadol HCl in vivo studies.

Major difference in particle size, minor difference in release profile: a case study of solid lipid nanoparticles

Solid lipid nanoparticles (SLN) have been widely used in a variety of drug delivery routes, which have the outstanding advantage of controlled drug release. The release of SLN is dominated by many factors, among which the particle size of SLN is a critical one. The aim of this project was to explore the relationship between drug release profile and particle size of SLN. SLN were synthesized via the hot high-pressure homogenization (HPH) method, budesonide (BUD) was used as the model drug, and BUD-SLN1-BUD-SLN4 with increasing particle size was obtained, i.e. 120, 240, 360, and 480 nm. The prepared SLN has good encapsulation efficiency, drug loading capacity, and stability. In vitro release behavior studies showed that the cumulative release of BUD-SLN in Tris-Maleate (Tris-M) media was negligible, while that in Tris-M plus pancreatin media or Tris-M-ethanol media obeyed Ritger-Peppas model or first-order kinetic model, respectively. Noticeably, the release behavior of SLN was to some extent related to the average particle size of SLN, but the correlation was insignificant when the intersection degree of particle size distribution was great. This study provides a new idea for the understanding of in vitro release of SLN and has a certain referencing value for the research and development of novel nanomedicines.

Osmotic-controlled release oral tablets: technology and functional insights

In recent years, oral osmotic tablets have sparked a therapeutic paradigm for controlled-release dosage forms due to their intrinsic insensitivity to physiological and physicochemical factors. Despite these benefits, the design of an optimal osmotic technology is precluded by various challenges. These limitations include manufacturing complexity, the lack of understanding of the functional mechanics, and inadequate optimization for the desired bio-performance. This paper systematically reviews the development of an osmotic-driven drug delivery system and the strategy for a zero-order release profile with an emphasis on swellable core technology. We discuss the applicability of the various types of osmotic tablets, their suitability to specific needs, and factors that drive the technology selection. Finally, we review the challenges, opportunities, and future perspectives associated with osmotic tablets.

Development, optimization and pharmacokinetic evaluation of biphasic extended-release osmotic drug delivery system of trospium chloride for promising application in treatment of overactive bladder

Background

The research was aimed with an approach to formulate biphasic extended-release system of trospium chloride resulting in controlled release of drug up to 24 h with prospects of better control on urinary frequency, efficacy, tolerability, and improved patient compliance. The push–pull osmotic pump (PPOP) bi-layered tablet of trospium chloride (60 mg) was developed with the use of immediate-release polymers in the pull layer (30 mg drug) and polyethylene oxide in the push layer (remaining 30 mg drug). The tablet was formulated by compression after non-aqueous granulation, seal coating, and semipermeable coating. The tablet prepared was laser drilled to create an orifice for drug release.

Results

Comparative in vitro dissolution and in vivo pharmacokinetic analysis of available marketed formulations demonstrated the complete drug release within 16–18 h; hence the developed biphasic extended-release system has its great importance as it provides zero-order release up to 24 h.

Conclusions

The developed biphasic extended-release drug delivery system of trospium chloride provides the drug release for 24 h with effective plasma concentration in comparison with the available marketed formulation. Extended release of drug from the developed formulation provides scope for its promising application in the treatment of overactive bladder (OAB).

Self-Nano-Emulsifying Drug-Delivery Systems: From the Development to the Current Applications and Challenges in Oral Drug Delivery

Approximately one third of newly discovered drug molecules show insufficient water solubility and therefore low oral bio-availability. Self-nano-emulsifying drug-delivery systems (SNEDDSs) are one of the emerging strategies developed to tackle the issues associated with their oral delivery. SNEDDSs are composed of an oil phase, surfactant, and cosurfactant or cosolvent. SNEDDSs characteristics, their ability to dissolve a drug, and in vivo considerations are determinant factors in the choice of SNEDDSs excipients. A SNEDDS formulation can be optimized through phase diagram approach or statistical design of experiments. The characterization of SNEDDSs includes multiple orthogonal methods required to fully control SNEDDS manufacture, stability, and biological fate. Encapsulating a drug in SNEDDSs can lead to increased solubilization, stability in the gastro-intestinal tract, and absorption, resulting in enhanced bio-availability. The transformation of liquid SNEDDSs into solid dosage forms has been shown to increase the stability and patient compliance. Supersaturated, mucus-permeating, and targeted SNEDDSs can be developed to increase efficacy and patient compliance. Self-emulsification approach has been successful in oral drug delivery. The present review gives an insight of SNEDDSs for the oral administration of both lipophilic and hydrophilic compounds from the experimental bench to marketed products.

In Situ Hexosomal Gel as a Promising Tool to Ameliorate the Transnasal Brain Delivery of Vinpocetine: Central Composite Optimization and In Vivo Biodistribution

Vascular dementia is a condition characterized by a wretched cerebral circulation which can lead to memory loss. Vinpocetine showed ability to promote the cerebral circulation and depict neuroprotective impacts. However, it suffers from poor bioavailability and requires frequent daily dosing which is not suitable for dementia patients. In our study, these limitations were overcome by the prolonged direct delivery of vinpocetine to the brain utilizing an intranasal in situ hexosomal gel. A central composite design was utilized and the optimum dispersion (consisting of 15% w/w of oleic acid and 5% w/w of pluronic F127) was loaded in an in situ gel system using gellan gum with 1% w/v. The optimized Formulae achieved a controlled drug release over 24 h and the pharmacokinetic data revealed that the C_max and AUC_0-24 in the rats' brain after the intranasal application of the dispersion and in situ gel were significantly higher relative to the vinpocetine solution applied intravenously at the same dose. The potential of both formulae to deliver vinpocetine to the brain directly through the intranasal route was confirmed by the high BTE% of 370.97% and 480.70% and the high DTP% of 73.04% and 79.19% for the dispersion and in situ gel, respectively.

Development and Evaluation of Controlled and Simultaneous Release of Compound Danshen Based on a Novel Colon-Specific Osmotic Pump Capsule

In the study, we developed a novel oral dosage form of Compound Danshen to resolve the problems of low bioavailability, disequilibrium in drug release, and stomach degradation of active components of Compound Danshen in conventional formulas. A colon-specific osmotic pump capsule (COPC) of Compound Danshen was prepared using a semipermeable shell with the core components. Using a single-factor method, we obtained the optimal formulation that consisted of Salvia miltiorrhiza extract, Panax notoginseng extract, Borneol, sodium chloride, polyethylene oxide wsr-N10, hydroxypropyl-β-cyclodextrin, and ludipress. Moreover, in vitro dissolution test showed simultaneous releases of active ingredients from Compound Danshen COPC over 12 h at pH 7.8, displaying zero-order release characteristics. The impetus of drug release mainly depended on the difference in osmotic pressure across the capsule shell. Next, scanning electron microscopy showed morphological changes in the capsule shell during the dissolution test. More importantly, pharmacokinetic study in beagle dogs indicated that relative bioavailability was 330.58% and retention time was greatly prolonged in Compound Danshen COPC, compared with those in marketed Compound Danshen tablet products. Finally, in vivo imaging studies in beagle dogs showed that COPC was stable in gastrointestinal tract and the drug was specifically released in the colon region. A colon-specific osmotic pump capsule (COPC) of Compound Danshen was developed and optimized to achieve simultaneous zero-order release of multiple active components of Compound Danshen in the colon. More importantly, the COPC have proved to improve the bioavailability and prolong the retention time of Compound Danshen, compared with those in a marketed product.

Preparation and in vitro/in vivo evaluation of azilsartan osmotic pump tablets based on the preformulation investigation

The objective of this study was to design and evaluate azilsartan osmotic pump tablets. Preformulation properties of azilsartan were investigated for formulation design. Azilsartan osmotic pump tablets were prepared by incorporation of drug in the core and subsequent coating with cellulose acetate and polyethylene glycol 4000 as semi-permeable membrane, then drilled an orifice at the center of one side. The influence of different cores, compositions of semipermeable membrane and orifice diameter on azilsartan release were evaluated. The formulation of core tablet was optimized by orthogonal design and the release profiles of various formulations were evaluated by similarity factor (f₂). The optimal formulation achieved to deliver azilsartan at an approximate zero-order up to 14 h. The pharmacokinetic study was performed in beagle dogs. The azilsartan osmotic pump tablets exhibited less fluctuation in blood concentration and higher bioavailability compared to immediate-release tablets. Moreover, there was a good correlation between the in vitro dissolution and in vivo absorption of the tablets. In summary, azilsartan osmotic pump tablets presented controlled release in vitro, high bioavailability in vivo and a good in vitro-in vivo correlation.

Formulation and in vivo assessment of terconazole-loaded polymeric mixed micelles enriched with Cremophor EL as dual functioning mediator for augmenting physical stability and skin delivery

The aim of the current study was to formulate terconazole (TCZ) loaded polymeric mixed micelles (PMMs) incorporating Cremophor EL as a stabilizer and a penetration enhancer. A 2³ full factorial design was performed using Design-Expert® software for the optimization of the PMMs which were formulated using Pluronic P123 and Pluronic F127 together with Cremophor EL. To confirm the role of Cremophor EL, PMMs formulation lacking Cremophor EL was prepared for the purpose of comparison. Results showed that the optimal PMMs formulation (F7, where the ratio of total Pluronics to drug was 40:1, the weight ratio of Pluronic P123 to Pluronic F127 was 4:1, and the percentage of Cremophor EL in aqueous phase was 5%) had a high micellar incorporation efficiency (92.98 ± 0.40%) and a very small micellar size (33.23 ± 8.00 nm). Transmission electron microscopy revealed that PMMs possess spherical shape and good dispersibility. The optimal PMMs exhibited superior physical stability when compared with the PMMs formulation of the same composition but lacking Cremophor EL. Ex vivo studies demonstrated that the optimal PMMs formula markedly improved the dermal TCZ delivery compared to PMMs lacking Cremophor EL and TCZ suspension. In addition, it was found that the optimal PMMs exhibited a greater extent of TCZ deposition in the rat dorsal skin relative to TCZ suspension. Moreover, histopathological studies revealed the safety of the optimal PMMs upon topical application to rats. Consequently, PMMs enriched with Cremophor EL, as a stable nano-system, could be promising for the skin delivery of TCZ.