Injectable Suspensions Research Articles

Construction of injectable micron-sized polymorphic vesicles for prolonged local anesthesia with weekly sustained release of ropivacaine

Currently, to overcome the short half-life of the local anesthetic ropivacaine, drug delivery systems such as nanoparticles and liposomes have been used to prolong the analgesic effect, but they are prone to abrupt release from the site of administration or have poor slow-release effects, which increases the risk of cardiotoxicity. In this study, injectable lipid suspensions based on ropivacaine-docusate sodium hydrophobic ion pairing (HIP) were designed to significantly prolong the duration of analgesia. The resulting ion-paired lipid suspension (HIP/LIPO) had a micrometer scale and a high zeta potential, which facilitates stable in situ retention. The strong interaction between docusate sodium and ropivacaine was verified using thermal and spectroscopic analyses, and the formation of micron-sized polymorphic vesicles was attributed to the mutual stabilizing interactions between ropivacaine-docusate sodium HIP, docusate sodium and lecithin. The HIP/LIPO delivery system could maintain drug release for more than 5 days in vitro and achieve high analgesic efficacy for more than 10 days in vivo, reducing the side effects associated with high drug doses. The stable HIP/LIPO delivery system is a promising strategy that offers a clinically beneficial alternative for postoperative pain management and other diseases.

Exploring the relationship between bulk Young’s Modulus of materials and milling efficiency during wet bead milling of pharmaceutical compounds

Wet bead milling (WBM) is one of the main approaches for manufacturing long acting injectable (LAI) suspensions, wherein the particle size of an Active Pharmaceutical Ingredient (API) is reduced in a liquid vehicle via grinding. A common challenge observed during WBM is long milling time to achieve target particle size, resulting in poor milling efficiency. The objective of this work was to identify potential API attributes predictive of milling efficiency during WBM. In this study, physical and mechanical properties of nine APIs were characterized. Formulations with these APIs were manufactured using WBM. Bulk Young’s Modulus was identified to have a significant influence on the rate of particle attrition. The rank order of Young’s Moduli of the APIs was consistent with that of milling efficiency, estimated by an empirical function defined in this study called Milling Resistance (ϕ), representing the holistic impact of milling time, tip speed, bead loading, and batch to chamber volume ratio. The identification of such intrinsic material properties, which provide an early evaluation of potential manufacturing risks, is beneficial to product development, as these assessments can be performed with limited quantities of materials and help identify and design out scale-up challenges.

Dynamic Column Studies of Multicomponent PFAS Sequestration Facilitated by Four Contrasting Injectable Adsorbent Suspensions and Associated PFAS Release in Simulated Groundwater

Dynamic Column Studies of Multicomponent PFAS Sequestration Facilitated by Four Contrasting Injectable Adsorbent Suspensions and Associated PFAS Release in Simulated Groundwater

J-TEC's efforts to industrialize regenerative medicine in Japan

Japan Tissue Engineering Co., Ltd., J-TEC, was launched in 1999 to industrialize regenerative medicine in Japan. We developed the first regenerative medicine product, JACE (autologous cultured epidermis), which received PMDA approval for treating serious burns in 2007. Then, JACC (autologous cultured cartilage), the second product, was approved in 2012 for efficacy on traumatic cartilage defects. In 2014, the Pharmaceutical Affairs Law was revised to the Pharmaceutical and Medical Device Act, and regenerative medicine products, including gene therapies, were newly classified to accelerate productization. Subsequently, Nepic (autologous cultured corneal epithelium) and Ocural (autologous cultured oral mucosal epithelium) for epithelialization of limbal stem cell deficiencies in ophthalmology were approved in 2020 and 2021, respectively. Furthermore, a new product, JACEMIN (autologous cultured epidermis maintaining melanocyte) for vitiligo treatment was approved in 2023. We have developed five products of regenerative medicine that construct human tissues to graft rather than injectable cell suspensions like drugs. To develop regenerative medicine products, it is necessary to ensure the safety of raw materials, standardize the cultivation process, examine cell characteristics on GLP tests, construct transportation methods, build GCTP facilities, and conduct clinical trials on GCP. Re-examinations of JACE for serious burns and JACC for cartilage defects were completed after 7 years of all-case postmarketing surveillance. The commercialization of these products has become a benchmark for domestic regulation and has induced the development of a regenerative medicine industry promoted by Japan.

Supercritical enhanced atomization induced particle entrapment for continuous production of injectable micro and nano-suspensions

The production of micro- and nanosized dry powder formulations of pharmaceutical drugs by spraying methods with high yields and desired rheological characteristics is typically challenging from laboratory up to commercial scales. In this work, supercritical CO2 was used in a supercritical enhanced atomization (SEA) process as a bottom-up method to create micro- and nanoparticles, with an enhanced control over their physicochemical properties, to produce injectable aqueous suspensions of itraconazole (ITZ). The existing drying chamber design was optimized to significantly improve the SEA process product yield. Additionally, a novel set-up was integrated for the continuous production of ITZ particles directly collected in an aqueous stabilizer media by the supercritical enhanced atomization-induced particle entrapment into suspension (SEA-PES) process. To evaluate the influence of various SEA-PES processing parameters on the particle size, morphology, residual solvent, and particle collection yield of each experimental run utilising the in-house built continuous set-up, a solvent screening study followed by a design of experiments (DoE) was carried out. Based on the given output parameters, tetrahydrofuran (THF) was selected as the optimum solvent for ITZ. The best excipient/s for stabilising ITZ micro- and nanoparticles in suspension, respectively, have previously been discovered to be vitamin E TPGS (0.5% w/w) in combination with PVP K30 (0.5% w/w). Using both the SEA and SEA-PES methods, homogeneous ITZ micro- and nanosuspensions (solid content of 200 mg/g) with D50 0.23 ± 0.06 μm and 3.5 ± 0.2 μm were produced, respectively. These suspensions were stable and resuspendable after 365 days of storage at 25 °C. Finally, utilising a newly developed discriminatory dissolution method, the in vitro release characteristics of ITZ micro- and nanosuspensions were evaluated. There was no significant difference between the SEA and SEA-PES methods to generate the drug micro- and nanosuspensions, according to both solid-state and in vitro release profiles analysis. This work provides proof of concept for establishing a cost-effective experimental platform for the continuous production of injectable micro-and nanosuspensions of ITZ.

FACTORS AFFECTING THE WITHDRAWAL PERIOD OF AMOXICILLIN FROM VETERINARY MEDICINAL PRODUCTS USED IN FOOD-PRODUCING ANIMALS

The withdrawal period of active substance residues from the animal’s body which products are intended for human consumption is an important criterion for the safety of veterinary medicinal products. This products cannot be authorized without establishing this important parameter. There are a number of veterinary medicinal products on the market of Ukraine and EU member states, which have the same active substance in the same concentration and pharmaceutical formulation, but the withdrawal period can differ significantly.
 The goal of our study was to determine the influence of various factors on the withdrawal period of amoxicillin from single-component oral (powders) and injectable (suspensions, long acting suspensions) dosage forms, which are included in the State Register of Veterinary Medicines of Ukraine and EU product database (UPD).
 As is known, amoxicillin is widely used for the treatment of infectious diseases in humans and animals, in particular food-producing ones, which are a source of food products intended for human consumption. From the point of the hazard of development acquired antimicrobial resistance when consuming products of animal origin contaminated with residues, the duration of the established withdrawal period is a question of great importance.
 As shown in the study results, the pharmacokinetic parameters of veterinary medicinal products, in particular bioavailability, as well as clinical characteristics of the disease, have a significant impact on the duration of the withdrawal period. Usually, the withdrawal period depends on the type of dosage form, and the amount and nature of excipients, because oral and injectable pharmaceutical formulations of the same veterinary medicinal product differ in terms of bioavailability from the systemic circulation and the site of injection. It was also defined that the duration of the withdrawal period depends on the amount of the administered dose of the veterinary medicinal product, the treatment duration, the target animal species, fasting conditions (before or after feeding), and the substrates used for feeding (dissolving in water or mixing with feed), analytical methods used to determine active substances or their metabolites, methods of the statistical processing results and differences between individual values established in a group of animals involved in the study.
 The importance of approving the withdrawal period for generic veterinary medicinal products manufactured by different companies is confirmed by studies carried out by the European Medicines Agency order at the request of the Competent authorities of individual EU countries in connection with the detection of the overestimated residue level compared with the established maximum limits over time, defined as the withdrawal period specified during product authorization.
 In two cases, changes were made to the Summary of Product Characteristics and package leaflets, regarding the extension of the withdrawal period of amoxicillin from certain tissues and for different target animal species. Marketing authorization holders are recommended to harmonize the withdrawal period for generic products with the established value for the reference veterinary medicinal products.

Development of long-acting injectable suspensions by continuous antisolvent crystallization: An integrated bottom-up process

Our present work elucidated the operational feasibility of direct generation and stabilization of long-acting injectable (LAI) suspensions of a practically insoluble drug, itraconazole (ITZ), by combining continuous liquid antisolvent crystallization with downstream processing (i.e., centrifugal filtration and reconstitution). A novel microchannel reactor-based bottom-up crystallization setup was assembled and optimized for the continuous production of micro-suspension. Based upon the solvent screening and solubility study, N-methyl pyrrolidone (NMP) was selected as the optimal solvent and an impinging jet Y-shaped microchannel reactor (MCR) was selected as the fluidic device to provide a reproducible homogenous mixing environment. Operating parameters such as solvent to antisolvent ratio (S/AS), total jet liquid flow rates (TFRs), ITZ feed solution concentration and the maturation time in spiral tubing were tailored to 1:9 v/v, 50 mL/min, 10 g/100 g solution, and 96 h, respectively. Vitamin E TPGS (0.5% w/w) was found to be the most suitable excipient to stabilize ITZ particles amongst 14 commonly used stabilizers screened. The effect of scaling up from 25 mL to 15 L was evaluated effectively with in situ monitoring of particle size distribution (PSD) and solid-state form. Thereafter, the suspension was subjected to centrifugal filtration to remove excess solvent and increase ITZ solid fraction. As an alternative, an even more concentrated wet pellet was reconstituted with an aqueous solution of 0.5% w/w Vitamin E TPGS as resuspending agent. The ITZ LAI suspension (of 300 mg/mL solid concentration) has the optimal PSD with a D10 of 1.1 ± 0.3 µm, a D50 of 3.53 ± 0.4 µm and a D90 of 6.5 ± 0.8 µm, corroborated by scanning electron microscopy (SEM), as remained stable after 548 days of storage at 25 °C. Finally, in vitro release methods using Dialyzer, dialysis membrane sac were investigated for evaluation of dissolution of ITZ LAI suspensions. The framework presented in this manuscript provides a useful guidance for development of LAI suspensions by an integrated bottom-up approach using ITZ as model API.

Facile Technology for Extemporaneous Preparation of Long-Acting Injectable Microparticulate Suspensions at the Patient Side

In this study, we present an innovative and facile in situ approach for extemporaneous preparation of sterile microparticles. An amazingly simple approach, in situ technology circumvents the stability, and scale up challenges as well as sterilization issues associated with long-acting particulate systems. Monophasic preconcentrates of donepezil base (DPZ), a model drug with a biodegradable polymer poly (DL-lactide-co-glycolide) (PLGA), with stabilizer were prepared by simple solution and sterilized by filtration (0.22 micron). The sterile preconcentrates when added to aqueous dextrose solution (total volume < 3mL) generated ready-to-inject DPZ PLGA microparticles (DPZ-PLGA-MP) with high reproducibility, entrapment efficiency (> 80%), and size ~ 80 micron. DPZ micro suspension(DPZ-MS) with high precipitation efficiency (> 90%) and size ~ 80 micron was obtained in a similar manner omitting PLGA. XRD and DSC study confirmed decreased crystallinity in the presence of PLGA. No interaction between PLGA and DPZ was evident in the FTIR study. The microparticulate dispersions exhibited good in vitro injectability when tested using the texture analyzer (force < 5 N). When evaluated using the dialysis bag method (Himedia 12-14kDa molecular weight cutoff), both microparticulate formulations exhibited controlled release up to 1week in vitro. Further, low burst release of ~ 10% at the end of 6h in the ex vivo chicken muscle study proposes great promise. Our data propose the facile extemporaneous generation of microparticles as a practical and promising approach for development of long-acting injectables. This facile approach could serve as platform technology for other drug candidates.

A Retrospective Analysis of Preclinical and Clinical Pharmacokinetics from Administration of Long-Acting Aqueous Suspensions.

Administration of long-acting injectable suspensions is an increasingly common approach to increasing patient compliance and improving therapeutic efficacy through less frequent dosing. While several long-acting suspensions have recently been marketed, parameters modulating drug absorption from suspension-based formulations are not well understood. Further, methods for predicting clinical pharmacokinetic data from preclinical studies are not well established. Together, these limitations hamper compound selection, formulation design and formulation selection through heavy reliance on iterative optimization in preclinical and clinical studies. This article identifies key parameters influencing absorption from suspension-based formulations through compilation and analysis of preclinical and clinical pharmacokinetic data of seven compounds marketed as suspensions; achievable margins for predicting the clinical dose and input rate from preclinical studies as a function of the preclinical species, the clinical injection location and the intended therapeutic duration were also established.

Nucleation kinetics-based solvent selection for the liquid antisolvent crystallization of a lipophilic intermediate

The fundamental understanding of solubility and nucleation kinetics are two primary pillars for liquid antisolvent crystallization (LASC) process development. In our present work, the solubility of intermediate A in four different solvents and binary mixtures with water, in the temperature range from 273 K to 323 K, was determined using a liquid chromatographic method to acquire the fundamental thermodynamic information for the LASC process. Intermediate A was monitored both in the solid phase and in the liquid phase by in line Raman spectroscopy. The importance of selection of the optimum scale and mixing conditions (volume and fluid dynamics dependency) for conducting metastable zone width (MSZW) measurements for the nucleation kinetics study, due to stochastic nature of nucleation, has been demonstrated to translate the findings to larger industrial scales. The 3.5 mL volume in reactor with a 3 blade downflow overhead impeller in the Crystalline™ (Technobis) was found to be an optimal platform for the data generation for the extraction of nucleation kinetics. The minimum detection threshold value (fN) reported in the literature was experimentally derived for the intermediate A-solvent systems used, covering the effect of supersaturation, reaction volume and agitation rate. The combined polythermal and antisolvent addition approach was applied to determine MSZWs and, subsequently, the kinetic parameters were estimated based on both linearized integral and 3D nucleation models. It was demonstrated how the derived parameters complemented with accurate solubility data are required to guide solvent selection for bottom-up generation of nanosuspensions. The findings were validated by conducting batch and continuous LASC of intermediate A. Particle size distributions derived from electron scanning microscopy obtained at similar driving forces confirmed the solvents selection order based on their nucleation tendency of dissolved intermediate A. These results serve as an example for applying a nucleation kinetics-based fundamental approach for solvent selection in the development of LASC process for generation of long-acting injectable suspensions.

Development of in vitro-in vivo correlations for long-acting injectable suspensions

Long-acting injectable (LAI) aqueous suspensions achieve extended drug release over a duration of weeks to months via slow dissolution of drug crystals with low solubility. There have been around ten LAI aqueous suspensions approved by the FDA to date and there are no generic equivalents for most of them. This may be largely due to the complex formulation development as well as the challenges in establishment of in vitro-in vivo correlation (IVIVC) for these products. Level A IVIVCs, using animal models, have been proven feasible for complex long-acting microsphere formulations with multiphasic release characteristics. Accordingly, it may be possible to develop IVIVCs for LAI aqueous drug suspensions since their release characteristics are relatively simple with only a drug dissolution phase. To establish IVIVCs for LAI drug suspensions, four compositionally equivalent medroxyprogesterone acetate LAIs with differences in processing and formulation factors (drug particle size and excipient source) were prepared using Depo-SubQ Provera 104 as the reference listed drug (RLD). Two in vitro release testing methods, modified based on USP apparatus 2 (with enhancer cells) and USP apparatus 4 (with semisolid adapters), were used. The in vivo release was investigated using a rabbit model. Level A IVIVCs were successfully established using the in vitro release profiles obtained with the USP apparatus 4. This is the first report of an IVIVC for LAI aqueous suspensions.

Design of Montelukast Nanocrystalline Suspension for Parenteral Prolonged Delivery.

BackgroundMontelukast (MTK), a representative leukotriene receptor antagonist, is currently being investigated as a potential candidate for treating Alzheimer’s disease. For potent and effective dosing in elderly patients, a parenteral prolonged delivery system is favored, with improved medication adherence with reduced dosage frequency.PurposeThis study aimed to design a nanocrystalline suspension (NS)-based MTK prolonged delivery system and evaluate its pharmacokinetics profile and local tolerability following subcutaneous administration.MethodsTo decelerate the dissolution rate, the amorphous MTK raw material was transformed into a crystalline state using a solvent-mediated transformation method and subsequently formulated into NS using a bead-milling technique. The MTK NSs were characterized by morphology, particle size, crystallinity, and in vitro dissolution profiles. The pharmacokinetic profile and local tolerability at the injection site following subcutaneous injection of MTK suspension were evaluated in rats.ResultsMicroscopic and physical characterization revealed that the amorphous MTK powder was lucratively transformed into a crystalline form in acidic media (pH 4). MTK crystalline suspensions with different diameters (200 nm, 500 nm, and 3 μm) were uniformly prepared using bead-milling technology, employing polysorbate 80 as suspending agent. Prepared crystalline suspensions exhibited analogous crystallinity (melting point, 150°C) and size-dependent in vitro dissolution profiles. MTK NSs with particle sizes of 200 nm and 500 nm provided a protracted pharmacokinetic profile for up to 4 weeks in rats, with a higher maximum drug concentration in plasma than the 3 μm-sized injectable suspensions. Histopathological examination revealed that MTK NS caused chronic granulomatous inflammation at the injection site, which resolved after 4 weeks.ConclusionThe MTK parenteral NS delivery system is expected to be a valuable tool for treating Alzheimer’s disease with extended dose intervals.

In vitro release testing method development for long-acting injectable suspensions

Long-acting injectable (LAI) suspensions are complex parenterals intended to control drug release over a duration of weeks to months. Any unpredictive drug release behavior may cause serious side effects. Therefore, it is important to understand the in vitro and in vivo performance, as well as the in vitro-in vivo correlation (IVIVC) of these products. There are some US FDA recommended in vitro release testing methods for LAI suspensions. However, the release duration of all the recommended methods is less than two days which may not be appropriate for the establishment of IVIVCs for LAIs considering that their in vivo efficacies range from weeks to months. To develop in vitro release testing methods that may better correlate with in vivo release with longer durations, three compositionally equivalent medroxyprogesterone acetate suspensions were prepared with different particle size, using Depo-SubQ Provera 104® as the reference listed drug (RLD). Four different methods based on USP apparatus 2 (with dialysis sacs, enhancer cells or in-house designed devices) and USP apparatus 4 (with semisolid adapters) were utilized. USP apparatus 2 with enhancer cells and USP apparatus 4 with semisolid adapters showed the best discriminatory ability and reproducibility for the LAI suspensions investigated.

A fast, validated UPLC method coupled with PDA-QDa detectors for impurity profiling in betamethasone acetate and betamethasone phosphate injectable suspension and isolation, identification, characterization of two thermal impurities

For impurity profiling of betamethasone acetate and betamethasone phosphate injectable suspensions, a quick, verified stability indicating UPLC technique incorporating the detectors PDA-QDa had been established. This method with an analysis time of 12min could able to separate all possible degradation impurities. Two of the thermal impurities have been identified in positive mode of detection by using QDa detector and isolated by using preparative HPLC. The method works at a flow rate of 0.5mL/min in column: Poroshell 120 EC C18 (100×2.1)mm, 1.9μm, maintained temperature precisely at 40°C. The M/Z values in ESI positive mode for the two new degradation impurities have been identified (M+H) as 393.22 (DP1), 363.17 (DP2) and confirmed by 1H NMR. The approach was also verified in accordance with the rules of ICH Q2 (R1). From LOQ quantity value to 150% quantity of specified concentration (2% for betamethasone and 0.5% for other impurities), the technique of UPLC-PDA-QDa was proven to be linear and accurate. Precision and ruggedness results showed˂5% RSD. Accuracy results showed more than 95% recovery from LOQ till 150% of impurity specification. This UPLC-PDA-QDa methodology was found specific, precise, stable and robust for quantification of all possible degradation impurities. The proposed method has been transferred to quality control laboratories to access the impurity profile during product storage.

Osmolality of Excipients for Parenteral Formulation Measured by Freezing Point Depression and Vapor Pressure - A Comparative Analysis.

To investigate the difference in methods to determine the osmolality in solutions of stabilizers used for long-acting injectable suspensions. The osmolality was measured by freezing point depression and vapor pressure for 11 different polymers and surfactants (PEG 3350, 4000, 6000, 8000, 20,000, PVP K12, K17 and K30, poloxamer 188, 388 and 407, HPMC E5, Na-CMC, polysorbate 20 and 80, vitamin E-TPGS, phospholipid, DOSS and SDS) in different concentrations. Independently of the measuring method, an increase in osmolality with increasing concentration was observed for all polymers and surfactants, as would be expected due to the physicochemical origin of the osmolality. No correlation was found between the molecular weight of the polymers and the measured osmolality. The osmolality values were different for PVPs, PEGs, and Na-CMC using the two different measurement methods. The values obtained by the freezing point depression method tended to be similar or higher than the ones provided by vapor pressure, overall showing a significant difference in the osmolality measured by the two investigated methods. For lower osmolality values (e.g. surfactants), the choice of the measuring method was not critical, both the freezing point depression and vapor pressure could be used. However, when the formulations contained higher concentrations of excipients and/or thermosensitive excipients, the data suggests that the vapor pressure method would be more suited.

Quantitative thin layer chromatography for the determination of medroxyprogesterone acetate using a smartphone and open-source image analysis

Intramuscular medroxyprogesterone acetate (MPA) products are commonly used to treat endometriosis and are the most widely used injectable contraceptives worldwide. Therefore, dependable quality screening of MPA injectables is a crucial measure necessary for ensuring that consumers are provided with safe and effective medications. Here, a thin-layer chromatography (TLC) method for MPA identification is combined with image analysis using a smartphone, 3D-printed light box, and open-source ImageJ software. The method's validation included two brands of MPA injectables, both at 150 mg mL−1 dosage. The TLC procedure used was based on the identity test found in The International Pharmacopoeia's Medroxyprogesterone injection monograph. Spots produced on the TLC plates were then photographed using a smartphone camera and quantified using ImageJ's image analysis software. The pixel data collected from each plate's standard spots were compared to the data generated from its sample spots. Data sets collected across multiple TLC plates and numerous days of method performance were evaluated to assess linearity, accuracy, precision, specificity, and robustness. Across the range of 75–125% of the target concentration, the method was found to have linearity of standard spots (with R2 generally greater than 0.99), overall accuracy of 101.0% (4.1% RSD), repeatability pooled standard deviation of 2.44%, intermediate precision pooled standard deviation of 3.68%, and observed demonstration of specificity and robustness. In low and middle-income countries (LMICs), quality screening of pharmaceutical products like MPA injectables can be challenging when testing resources are expensive, difficult to procure, or complex to utilize. The results of the TLC/ImageJ method validation suggest that this simple procedure that requires minimal resources may serve as a viable option for reliable quality screening of MPA levels in injectable suspensions.

Impact of particle flocculation on the dissolution and bioavailability of injectable suspensions

Injectable suspensions occasionally exhibit variations in dissolution and bioavailability, which may impact the clinical outcome of the drug product. Here, variation in the injection method (i.e., applied shear) for triamcinolone acetonide (TA) injectable suspension (40 mg/mL) altered the flocculation state of the particles and subsequently their dissolution. Notably, TA suspensions contained primary particles of approximately 2 µm and secondary flocculates of tens of microns. The conversion between flocculated and deflocculated particles was rapid, reversible and highly shear dependent. As such, changing shear rates during laser diffraction (LD) measurement like stirring rate, sonication, and sample introduction method (micropipette vs 25-gauge needle) may result in variability in particle size distributions (PSD) that have the potential to alter drug dissolution. Furthermore, a non-sink, discriminatory in vitro release testing (IVRT) method was developed, which combined in-situ fiber optic UV with LD to simultaneously monitor the dissolution and changing PSD of the suspension. The simultaneously measured dissolution and PSD data showed that flocculated and deflocculated particles followed different dissolution pathways. Importantly, deflocculated particles dissolved up to six times faster than the flocculated particles. Similar shear-induced changes during injection could occur in a clinical setting and have implications for drug bioavailability.

Preparation of high concentration protein powder suspensions by milling of lyophilizates

Pharmaceutical formulations utilizing protein drugs as powders can be used as drug delivery systems in various ways. Besides powders for inhalation, another promising approach is their use as suspensions in non-aqueous liquids for subcutaneous administration providing high protein stability and good injectability. In this study protein powder suspensions were prepared using a swing-mill. Milling of lyophilizates containing a model monoclonal antibody in presence of the suspension vehicle was compared to cryogenic dry milling. Wet media milling led to injectable suspensions, but resulted in monomer loss and increase in protein aggregation. When the lyophilizates were cryogenic dry ball milled less aggregation and monomer loss were detected. Differences related to protein integrity were found for different process parameters, which were successfully optimized. If not cooled with liquid nitrogen, dry milling resulted in increased damage to the mAb. The type of polyol stabilizer, as well as the protein to stabilizer ratio, did not affect the preservation of protein integrity.As finding the right milling duration is time and resource intensive, a correlation between lyophilizate cake hardness and milling duration was established. Based on this approach high concentration lyophilizates were successfully micronized. Suspensions of cryogenic milled powders lead to clogging of 25G needles, which could be prevented by an additional sieving step. Depending on the suspension vehicle, low viscosity formulations (<10 mPa·s) even at high concentrations (≥100 mg/ml protein concentration) were obtained featuring good injectability.

Estriol dissolving microneedle patches for protection against ionizing radiation-induced injury

Estriol can be used to treat radiation-induced leukopenia by increasing peripheral blood leukocytes and therefore it plays an important role in radiation protection. However, only high-dose injectable suspensions are available when estriol is used to combat against ionizing radiation-induced injury. Intramuscular (i.m.) administration of estriol is very painful and inconvenient, and the lack of timely self-administered formulation greatly limits the wide application of estriol. This will facilitate quick response under emergent conditions in complementary with the available estriol formulations. Herein, we prepared estriol microneedle (MNs) patches for the convenient and efficient treatment of radiation-induced injury. A biocompatible polymer, polyvinylpyrrolidone K90, was dissolved in an estriol solution of methanol and cast into a mold to obtain conical-shaped MNs. N-vinyl pyrrolidone was poured on the base of the MNs and photocured to enhance the mechanical strength of estriol MNs (EMNs). EMNs were easily pierced 200 μm into the mouse skin. More importantly, the EMNs tips were dissolved very quickly within 5 min so that the drugs could permeate across skin. Mouse models of ionizing radiation-induced injury were established with 6.5 Gy radiation of 60Co γ ray. Moreover, EMNs increased peripheral blood leukocytes in irradiated mice, protected the bone marrow hematopoietic system, and improved the survival rate of the irradiated mice to 80%. EMNs are a promising transdermal drug delivery system that allows for easy, rapid administration and protects the body from damage caused by ionizing radiation.

A low-cost and portable near-infrared spectrometer using open-source multivariate data analysis software for rapid discriminatory quality assessment of medroxyprogesterone acetate injectables

Medroxyprogesterone acetate (MPA) injectable suspensions are used by millions of women for family planning and hormonal therapy. Falsified or substandard medications may result in a health risk for consumers. Near-infrared spectroscopy (NIR) has previously been applied as a means of non-destructive and rapid screening of product quality compliance. These methods offer advantages but can be logistically and cost prohibitive for field use in resource limited areas. Here, a handheld spectrometer (900–1700 nm) with open-sourced software is used to evaluate vials of MPA from three suppliers (N = 227 vials) and verified by a benchtop UV–VIS-NIR (350–2500 nm) with licensed software. Multivariate data analysis assesses the spectral signatures of samples and builds a discriminant classification method based on Mahalanobis distances calculated from a principal component analysis scores. The handheld device paired with open-source software resulted in a product discrimination accuracy of 100% (verified by benchtop UV–VIS-NIR and chemical testing data) as well indicating that the low-cost field portable device is suitable for rapidly assessing samples in resource limited areas for consistency of manufacturing and sourcing.