Opportunities for milk and milk-related systems as 'new' low-cost excipient drug delivery materials

Infant formula as a solid lipid dose form for enhancement of the oral bioavailability of cannabidiol for paediatric patients

Cannabinoids can save paediatric patients from harmful psychological conditions caused by epilepsy. However, the limited aqueous solubility of the drug presents a limitation to oral absorption and bioavailability. Previous studies have shown the enhancement of oral bioavailability for poorly water-soluble drugs using milk or milk-based products like infant formula as a novel lipid-based formulation, due to digestion of the lipids to enhance drug solubility. that is particularly well suited to infants and in low economy settings. Therefore, this study has investigated the in vitro solubilization enhancement of cannabidiol (CBD) in milk-based products during digestion using synchrotron small angle X-ray scattering, followed by pharmacokinetic studies to determine the relative oral bioavailability. The in vitro results, coupled with in vivo data, demonstrate a two-fold increase in the oral bioavailability of CBD in bovine milk as well as infant formula. The results of this study indicate the potential for infant formula to be considered as a novel formulation approach for CBD. Further study is encouraged for more drugs with infant formula to strengthen the correlation between the solubilization of drug and their oral bioavailability.

In Operando Analysis of Milk-Based Oral Formulations during Digestion Using Synchrotron Small-Angle X-ray Scattering Coupled to Low-Frequency Raman Spectroscopy

A low-frequency Raman (LFR) probe was coupled to an in-line small-angle X-ray scattering (SAXS) beamline to test the capabilities of a combinatory approach for the determination of lipid and drug behavior during the enzymatic lipolysis of milk-based oral formulations. Cinnarizine was used as the model drug, and its solubilization dynamics as well as its potential impact on the supramolecular structures formed by the digestion products of bovine milk were evaluated from the perspective of both techniques. The SAXS data were superior in distinguishing various liquid crystalline assemblies formed during the digestion process, with LFR providing complementary information regarding the formation of calcium soaps. On the other hand, studying changes in the LFR domain allowed the differentiation of drug solubilization and precipitation; processes that were less clear from the X-ray scattering data. Given the relative simplicity of the combined experimental setup, these results highlight the advantages that the combination of the two techniques can provide for understanding and developing new lipid-based formulations and will help to translate the results obtained at synchrotron facilities to routine analysis procedures in laboratory/industry-based environments.

Synergistic vesicle-vector systems for targeted delivery

With the immense progress in drug delivery systems (DDS) and the rise of nanotechnology, challenges such as target specificity remain. The vesicle-vector system (VVS) is a delivery system that uses lipid-based vesicles as vectors for a targeted drug delivery. When modified with target-probing materials, these vesicles become powerful vectors for drug delivery with high target specificity. In this review, we discuss three general types of VVS based on different modification strategies: (1) vesicle-probes; (2) vesicle-vesicles; and (3) genetically engineered vesicles. The synthesis of each VVS type and their corresponding properties that are advantageous for targeted drug delivery, are also highlighted. The applications, challenges, and limitations of VVS are briefly examined. Finally, we share a number of insights and perspectives regarding the future of VVS as a targeted drug delivery system at the nanoscale.

Evaluating human milk as a drug delivery vehicle for clofazimine to premature infants

Human milk is proposed as a drug delivery vehicle suitable for use in neonatal patients. Clofazimine, traditionally used for the treatment of leprosy and tuberculosis, is emerging as a treatment for cryptosporidiosis in infants, however its poor aqueous solubility has led to its commercial formulation as a waxy lipid formulation in a capsule, a format that is not suitable for infants. In this study, the evaluation of pasteurised human milk for the delivery of clofazimine was investigated using an in vitro lipolysis model to simulate gastric and intestinal digestion. The total lipid composition of the human milk was characterised alongside the liberated fatty acid species following digestion for comparison to alternative lipid-based delivery systems. Small-angle X-ray scattering was used to measure the presence of crystalline clofazimine during digestion and hence the extent of drug solubilisation. High-performance liquid chromatography was used to quantify the mass of clofazimine solubilised per gram of human milk fat (drug-to-fat ratio) in digested and undigested human milk. The digestion process was essential for the solubilisation of clofazimine, with digested human milk solubilising a sufficient dose of clofazimine for treatment of a premature infant. Human milk solubilised the clofazimine to a greater extent than bovine milk and infant formula during digestion, most likely as a result of differing lipid composition and increased long-chain fatty acid concentrations. These findings show that human milk enhances the solubility of clofazimine as a model drug and may be a suitable drug delivery vehicle for infant populations requiring therapeutic treatment.

In Situ Monitoring of Drug Precipitation from Digesting Lipid Formulations Using Low-Frequency Raman Scattering Spectroscopy

Low-frequency Raman spectroscopy (LFRS) is a valuable tool to detect the solid state of amorphous and crystalline drugs in solid dosage forms and the transformation of drugs between different polymorphic forms. It has also been applied to track the solubilisation of solid drugs as suspensions in milk and infant formula during in vitro digestion. This study reports the use of LFRS as an approach to probe drug precipitation from a lipid-based drug delivery system (medium-chain self-nanoemulsifying drug delivery system, MC-SNEDDS) during in vitro digestion. Upon lipolysis of the digestible components in MC-SNEDDS containing fenofibrate as a model drug, sharp phonon peaks appeared at the low-frequency Raman spectral region (<200 cm^-1), indicating the precipitation of fenofibrate in a crystalline form from the formulation. Two multivariate data analysis approaches (principal component analysis and partial least squares discriminant analysis) and one univariate analysis approach (band ratios) were explored to track these spectral changes over time. The low-frequency Raman data produces results in good agreement with in situ small angle X-ray scattering (SAXS) measurements with all data analysis approaches used, whereas the mid-frequency Raman requires the use of PLS-DA to gain similar results. This suggests that LFRS can be used as a complementary, and potentially more accessible, technique to SAXS to determine the kinetics of drug precipitation from lipid-based formulations.

Implications of the Digestion of Milk-Based Formulations for the Solubilization of Lopinavir/Ritonavir in a Combination Therapy

The development of formulation approaches to coadminister lopinavir and ritonavir antiretroviral drugs to children is necessary to ensure optimal treatment of human immunodeficiency virus (HIV) infection. It was previously shown that milk-based lipid formulations show promise as vehicles to deliver antimalarial drugs by enhancing their solubilization during the digestion of the milk lipids under intestinal conditions. In this study, we investigate the role of digestion of milk and infant formula on the solubilization behavior of lopinavir and ritonavir to understand the fate of drugs in the gastrointestinal (GI) tract after oral administration. Small angle X-ray scattering (SAXS) was used to probe the presence of crystalline drugs in suspension during digestion. In particular, the impact of one drug on the solubilization of the other was elucidated to reveal potential drug-drug interactions in a drug combination therapy. Our results showed that lopinavir and ritonavir affected the solubilization of each other during digestion in lipid-based formulations. While addition of ritonavir to lopinavir improved the overall solubilization of lopinavir, the impact of lopinavir was to reduce ritonavir solubilization as digestion progressed. These findings highlight the importance of assessing the solubilization of individual drugs in a combined matrix in order to dictate the state of drugs available for subsequent absorption and metabolism. Enhancement in the solubilization of lopinavir and ritonavir in a drug combination setting in vitro also supported the potential for food effects on drug exposure.

Enhanced oral bioavailability from food protein nanoparticles: A mini review

The oral route is the most desirable drug administration path. The oral bioavailability is always compromised from the poor physicochemical and/or biopharmaceutical properties of the active pharmaceutical ingredients. Food protein nanoparticles show promise for oral drug delivery, with improved biosafety and cost-effectiveness compared to polymeric nanoparticles. More importantly, diverse food proteins provide "choice and variety" to meet the challenges faced by different drugs in oral delivery resulting from low solubility, poor permeability, and gastrointestinal stability. The abundance of hydroxyl, amino, and carboxyl groups in food proteins allows easy surface modification of the nanoparticles to impart unique functions. Albeit being in its infancy, food protein nanoparticles exhibit high capability to enhance oral bioavailability of a wide range of drugs from small molecules to biomacromolecules. Considering the rapid growth of the field, the achievements and mechanisms of food protein nanoparticles in enhancing oral bioavailability are reviewed. Factors affecting the performance of food protein nanoparticles are discussed with the purpose to inspire the development of food protein nanoparticle-based oral drug delivery systems.

Attitudes toward a novel breastfeeding-mediated drug and nutrient delivery system: A qualitative study

The objective of this study was to determine the attitudes and impressions of breastfeeding mothers and healthcare practitioners towards a device concept integrating breastfeeding with infant drug and nutrient administration. This was an exploratory qualitative study involving 20 breastfeeding mothers and 6 healthcare practitioners from the Suffolk and Middlesex County areas of Massachusetts, USA each individually interviewed. Interview transcription of the semi-structured interviews by an independent service began during data collection, and data coding into major themes continued until and after data saturation was reached. Repeated medication delivery with a reusable product was highlighted as a potential use case for the device concept; ease of use and cleaning as well as cost, familiarity with the method, and infant response were identified as critical considerations. Participants questioned device suitability with liquid formulations (as opposed to non-liquid), while potential advantages over alternative medication delivery technology like oral syringes were identified, including a more "natural" feeling. Most participants had prior knowledge of, or personal experience with, devices like commercially available nipple shields. Attitudes towards the NSDS were not determined by experience with nipple shields, however. The participants' prior exposure to nipple shields is in contrast to related studies in Kenya and South Africa where commercial nipple shields were not widely known and where specific concerns surrounding potential community stigma to an unknown device were raised by participants.

Revisiting the Dissolution of Praziquantel in Biorelevant Media and the Impact of Digestion of Milk on Drug Dissolution

Praziquantel is a poorly water-soluble drug used to treat parasitic infections. Previous studies have suggested that its rate and extent of dissolution in milk and biorelevant media are slow and limited compared to dissolution in the pharmacopoeial-recommended medium, despite being reported as displaying a positive food effect upon administration. This study aimed to revisit the dissolution of praziquantel in biorelevant media and milk to better understand this apparent dichotomy. The context of digestion was introduced to better understand drug solubilisation under more relevant gastrointestinal conditions. The amount of praziquantel solubilised in the various media during digestion was quantified using high performance liquid chromatography (HPLC) and the kinetics of dissolution were confirmed by tracking the disappearance of solid crystalline drug using in situ small angle X-ray scattering (SAXS). For the dissolution media, where sodium lauryl sulfate (SLS) is typically included as a wetting agent, a prominent effect of SLS on drug dissolution was also apparent where >2.5 fold more drug was solubilised in SLS-containing dissolution medium compared to that without (0.1 M HCl only). In milk, significant dissolution of praziquantel was observed only during digestion and not during dispersion, hence suggesting that (1) milk can be potentially administered with praziquantel to improve oral bioavailability and (2) incorporating a digestion step into existing in vitro dissolution testing can better reflect the potential for a positive food effect when lipids are present.

Milk Oral Lyophilizates with Loratadine: Screening for New Excipients for Pediatric Use

The development of suitable formulations for the pediatric population remains a challenging field with great advances reported every year in terms of excipients and technology. When developing pediatric formulations, the acceptability of medicines represents a key element to consider. For this reason, milk can be a widely accepted excipient with taste-masking properties and supplementary advantages for drug solubility. In recent years, the orodispersible dosage forms have come onto the market as child-friendly formulations. The current study aimed to develop freeze-dried orodispersible dosage forms containing bovine milk or infant formulae as the main component. In the first stage, an exploratory study evaluated the mechanical properties of placebo milk formulations and the suitability of milk as a matrix-forming agent. As the appropriate mechanical strength to withstand manipulation was demonstrated, milk oral lyophilizates were loaded with a poorly soluble model API, loratadine. Hence, a D-optimal design was conducted to prepare milk lyophilizates with loratadine and to evaluate the effects of three factors (dose of loratadine, the lyophilizate size, and the type of milk) and their interactions. Finally, three formulations were prepared to confront the predictions of the DoE and further studied to thoroughly understand the observed effects. The experimental results showed the potential of milk in the development of oral lyophilizates loaded with different doses of suspended API.