Development and validation of an in vitro–in vivo correlation (IVIVC) model for propranolol hydrochloride extended-release matrix formulations

Miniaturized screening and performance prediction of tailored subcutaneous extended-release formulations for preclinical in vivo studies

Microencapsulation of active pharmaceutical ingredients (APIs) for preparation of long acting injectable (LAI) formulations is an auspicious technique to enable preclinical characterization of a broad variety of APIs, ideally independent of their physicochemical and pharmacokinetic (PK) characteristics. During early API discovery, tunable LAI formulations may enable pharmacological proof-of-concept for the given variety of candidates by tailoring the level of plasma exposure over the duration of various timespans. Although numerous reports on small scale preparation methods for LAIs utilizing copolymers of lactic and glycolic acid (PLGA) and polymers of lactic acid (PLA) highlight their potential, application in formulation screening and use in preclinical in vivo studies is yet very limited. Transfer from downscale formulation preparation to in vivo experiments is hampered in early preclinical API screening by the large number of API candidates with simultaneously very limited available amount in the lower sub-gram scale, lack of formulation stability and deficient tunability of sustained release. We hereby present a novel comprehensive platform tool for tailored extended-release formulations, aiming to support a variety of preclinical in vivo experiments with ranging required plasma exposure levels and timespans. A novel small-scale spray drying process was successfully implemented by using an air brush based instrument for preparation of PLGA and PLA based formulations. Using Design of Experiments (DoE), required API amount of 250 mg was demonstrated to suffice for identification of dominant polymer characteristics with largest impact on sustained release capability for an individual API. BI-3231, a hydrophilic and weakly acidic small compound with good water solubility and permeability, but low metabolic stability, was used as an exemplary model for one of the many candidates during API discovery. Furthermore, an in vitro to in vivo correlation (IVIVC) of API release rate was established in mice, which enabled the prediction of in vivo plasma concentration plateaus after single subcutaneous injection, using only in vitro dissolution profiles of screened formulations. By tailoring LAI formulations and their doses for acute and sub-chronic preclinical experiments, we exemplary demonstrate the practical use for BI-3231. Pharmacological proof-of-concept could be enabled whilst circumventing the need of multiple administration as result of extensive hepatic metabolism and simultaneously superseding numerous in vivo experiments for formulation tailoring.

Investigating in-vitro functionality and in-vivo taste assessment of eco-friendly Tadalafil Pastilles

Tadalafil (TDL) has poor bioavailability due to the less aqueous solubility and bitter taste. Oral solid dosage forms, especially tablets, have a broad market worldwide. Constraints of tablets are a long process, pollution, high processing cost, and requiring more excipient. The research was performed to optimize an eco-friendly immediate-acting pastille of TDL to put forward an alternate formulation to a tablet using advanced data mining tools. Another objective is to assess the taste masking of TDL using the Brief Access Taste Aversion (BATA) model. The amount of PEG-4000, Polyox N-10, and Kyron T-314 were chosen as critical material attributes from failure mode effect analysis. Box-Behnken design (BBD) was utilized to optimize the pastilles and ascertained the significant impact of chosen variables on disintegration time and % CDR at 10 min. The control strategy and optimal region were located using an overlay plot. The pastilles were able to release the drug within 15 min due to faster disintegration. The formulated pastilles were of uniform size, shape, and mechanical strength. The bitter taste of TDL was masked and confirmed by the BATA model. The newer formulation may be helpful in the industry due to its eco-friendly, single-step, and economical process. It unlocks a new direction in the field of oral solid dosage form as an alternative to tablets.

Injectable drug delivery systems of doxorubicin revisited: In vitro-in vivo relationships using human clinical data

A growing number of nanomedicines entered the clinical trials and improved our understanding of the in vivo responses expected in humans. The in vitro drug release represents an important critical quality attribute involved in pharmacokinetics. Establishing in vitro-in vivo relationships for nanomedicines requires a careful analysis of the clinical data with respect to the unique differences between drugs and nanomedicines. Also, the biorelevant assay must reflect the release mechanism of the carrier. Four drug delivery systems of doxorubicin were evaluated for their in vitro release behavior under biorelevant conditions using the dispersion releaser. The pharmacokinetics observed during the first-in-men clinical trials were analyzed using a custom-made physiologically-based nanocarrier biopharmaceutics model. The drug product Lipodox® and the clinical candidate NanoCore-7.4 were evaluated to validate the model. Afterward, the in vivo performances of the preclinical candidates NanoCore-6.4 and doxorubicin-loaded nano-cellular vesicle technology systems (an extracellular vesicle preparation) were predicted. In vitro and in vivo release were in good correlation as indicated by the coefficients of determination of 0.98648 (NanoCore-7.4) and 0.94107 (Lipodox®). The predictions required an estimation of the carrier half-life in blood circulation leading to considerable uncertainty. Still, the simulations narrow down the possible scenarios in the clinical evaluation of nanomedicines and provide a valuable addition to animal studies.

Demonstration of Advanced Data Mining Tools for Optimization of Pellets Employing Modified Extrusion-pelletization Technique

Background:

The multi particulate drug delivery system is preferred due to its numerous advantages but the batch to batch consistency and to achieve desired physical properties are the major challenges in the formulation of such dosage form.

Objective:

The objective of the present study was to explore the concept of quality by design for the development of galantamine HBr controlled release pellets using a modified palletization technique.

Methods:

Compritol 888 and Ethocel were chosen as hydrophobic release retardants, while Avicel was chosen as pelletization aid. A compatibility study was conducted between the drug and excipients. Drug loaded extrudes were prepared by using a mixture of isopropyl alcohol, and dichloromethane. Before converting the wet extrudes into pellets, pregelatinized starch was sprinkled on them to improve the physical properties of the pellets. The pellets were characterized for size, shape, and flow. The critical evaluation parameter was the drug dissolution pattern in distilled water. The dissolution data were treated with advanced data mining techniques. The in-vivo profile was predicted employing pharmacokinetic parameters of the drug and in-vitro drug release data of optimized batch pellets.

Results:

The failure mode and effect analysis revealed that the amount of Compritol 888 ATO and Ethocel were the most critical formulation parameters. The results of FTIR and DSC revealed compatibility between the drug and the excipients. The spherical pellets exhibited good flow. The drug dissolution studies of the batches, prepared according to the central composite design, revealed modified drug release. Multiple regression analysis and analysis of variance were performed to identify statistically significant factors. Contour plots demonstrated the impact of the amount of Compritol 888 and ethyl cellulose. The Design-Expert software was used to identify optimized formulation. The predicted in-vivo plasma concentration-time profile revealed the modified drug release up to 12h.

Conclusions:

Compritol and Ethocel were able to retard the drug release up to 12 hrs in distilled water. The innovative finding of this study is the use of a dry binder (pregelatinized starch) to improve the characteristics of pellets. Other dry binders are expected to show a similar effect. The newer processing technique can be of use in the industry.

Intranasal Surface-Modified Mosapride Citrate-Loaded Nanostructured Lipid Carriers (MOS-SMNLCs) for Treatment of Reflux Diseases: In vitro Optimization, Pharmacodynamics, and Pharmacokinetic Studies

Gastroesophageal reflux disease (GERD) is an esophageal injury occurred when the stomach contents reflux abnormally into the esophagus. GERD complications include esophageal adenocarcinoma. Mosapride (MOS) is a safe prokinetic agent potentially used to treat GERD. Yet, its low solubility and bioavailability due to extensive first-pass metabolism limits its applications. This study aimed to formulate MOS nanostructured lipid carriers (MOS-NLCs) via the intranasal route to improve its bioavailability. Melt-emulsification low temperature-solidification technique using 2³ full factorial design was adopted to formulate MOS-NLCs. Eight formulae were prepared and assessed in terms of entrapment efficiency (%EE), particle size, and in vitro release. Glycerol addition significantly reduced the particle sizes and improved %EE and %drug released. Surface modification using chitosan was applied. The optimized MOS surface-modified nanostructured lipid carriers (MOS-SMNLCs-F7)(stearic acid, 4% glycerol, 0.5% LuterolF127, 0.5% chitosan) showed low particle size 413.8 nm ± 11.46 nm and high %EE 90.19% ± 0.06% and a threefold increase in permeation of MOS with respect to the drug suspension. MOS-SMNLCs (F7) was also evaluated for its bioavailability compared with drug suspension and commercial product. Statistical analysis revealed a significant increase in gastric emptying rate to be 21.54 ± 1.88 contractions/min compared with10.02 ± 0.62 contractions/min and 8.9 ± 0.72 contractions/min for drug suspension and oral marketed product respectively. Pharmacokinetic studies showed 2.44-fold rise in bioavailability as compared to MOS suspension and 4.54-fold as compared to the oral marketed product. In vitro/in vivo studies proven to level A correlation between in vitro permeation through sheep nasal mucosa and in vivo absorption. Therefore, MOS-SMNLCs could be considered a step forward towards enhancing the clinical efficacy of Mosapride.

Silymarin nanoparticles through emulsion solvent evaporation method for oral delivery with high antioxidant activities, bioavailability, and absorption in the liver

Silymarin (SM), a well-known hepatoprotective drug, is widely used to treat liver disorders. Silymarin nanoparticles (SMNs) were prepared through emulsion solvent evaporation and freeze-drying methods to improve their solubility.

Development of pH sensitive microparticles of Karaya gum: By response surface methodology

The objective of the proposed work was to prepare pH sensitive microparticles (MP) of Karaya gum using distilled water as a solvent by spray drying technique. Different formulations were designed, prepared and evaluated by employing response surface methodology and optimal design of experiment technique using Design Expert(®) ver 8.0.1 software. SEM photographs showed that MP were roughly spherical in shape and free from cracks. The particle size and encapsulation efficiency for optimized MP was found to be between 3.89 and 6.5 μm and 81-94% respectively with good flow properties. At the end of the 12th hour the in vitro drug release was found to be 96.9% for the optimized formulation in pH 5.6 phosphate buffer. Low prediction errors were observed for Cmax and AUC0-∞ which demonstrated that the Frusemide IVIVC model was valid. Hence it can be concluded that pH sensitive MP of Karaya gum were effectively prepared by spray drying technique using aqueous solvents and can be used for treating various diseases like chronic hypertension, Ulcerative Colitis and Diverticulitis.

Formulation and evaluation of controlled-release of telmisartan microspheres: In vitro/in vivo study

The aim of this work was to design a controlled-release drug-delivery system for the angiotensin-II receptor antagonist drug telmisartan. Telmisartan was encapsulated with different EUDRAGIT polymers by an emulsion solvent evaporation technique and the physicochemical properties of the formulations were characterized. Using a solvent evaporation method, white spherical microspheres with particle sizes of 629.9–792.1 μm were produced. The in vitro drug release was studied in three different pH media (pH 1.2 for 2 hours, pH 6.8 for 4 hours, and pH 7.4 for 18 hours). The formulations were then evaluated for their pharmacokinetic parameters. The entrapment efficiency of these microspheres was between 58.6% and 90.56%. The obtained microspheres showed good flow properties, which were evaluated in terms of angle of repose (15.29–26.32), bulk and tapped densities (0.37–0.53 and 0.43–0.64, respectively), Carr indices and Hausner ratio (12.94–19.14% and 1.14–1.23, respectively). No drug release was observed in the simulated gastric medium up to 2 hours; however, a change in pH from 1.2 to 6.8 increased the drug release. At pH 7.4, formulations with EUDRAGIT RS 100 showed a steady drug release. The microsphere formulation TMRS-3 (i.e., microspheres containing 2-mg telmisartan) gave the highest C_max value (6.8641 μg/mL) at 6 hours, which was three times higher than C_max for telmisartan oral suspension (TOS). Correspondingly, the area under the curve for TMRS-3 was 8.5 times higher than TOS. Particle size and drug release depended on the nature and content of polymer used. The drug release mechanism of the TMRS-3 formulation can be explained using the Higuchi model. The controlled release of drug from TMRS-3 also provides for higher plasma drug content and improved bioavailability.