Studies on the pH-dependent solubility of various grades of calcium phosphate-based pharmaceutical excipients

Development of Complex Generics and Similar Biological Products: An Industrial Perspective of Reverse Engineering

Generic drugs are developed to be bioequivalent to innovator formulation, matching them in dosage form, safety, strength, quality and efficacy. Known as "interchangeable multi-source pharmaceutical products," generics play a crucial role in reducing therapeutic costs and enhancing patient compliance. Over the past decade, generics have accounted for more than 90% of prescriptions in the U.S., which has driven down the average price of these drugs to nearly match production costs once market competition grows. Simple generics of small-molecule drugs are often produced through trial and error based on existing data, but complex generics require advanced techniques like reverse engineering to replicate the brand drug's release profile. These complex generics include sophisticated drug delivery forms that ensure the therapeutic agent is released gradually, maximizing effectiveness. Conversely, similar biological products highly similar to approved biologics-undergo rigorous analytical and clinical evaluations due to their complexity and the nature of biologic production. The increased demand for similar biological products is driven by expiring biologic patents, economic incentives, and regulatory advancements, with the market expected to grow significantly by 2026. The Biologic Price Competition and Innovation Act (BPCIA) enable abbreviated approvals for similar biological products, promoting affordability. Despite minor differences from original biologics, similar biological products undergo extensive testing to ensure safety and efficacy, following global regulatory guidelines that emphasize strict quality standards. This framework is essential for expanding patient access to effective therapies for conditions like cancer and autoimmune diseases while supporting healthcare sustainability.

Dry Powder Inhalation of Nintedanib in Dibasic Calcium Phosphate for Targeting the Lungs in Pulmonary Fibrosis

We prepared three variants of nintedanib dry powder inhalations (DPIs), one with dibasic calcium phosphate dihydrate (CaHPO4·2H2O) and two with lactose monohydrate as the carrier. CaHPO4 is not reported as a DPI excipient. We compared nintedanib pharmacokinetics and efficacy of the CaHPO4 formulation against bleomycin-induced pulmonary fibrosis following oral (3.875 mg/q12h) and DPI (200 μg/12 h) dosing in rats. Blood plasma Cmax, Tmax, and AUC resulting from oral dosing and DPI were 780 versus 147.5 μg/mL, 2.47 versus 2.22 h, and 5562 versus 1094 μg/mL·h, respectively. Drug remaining in the lungs and airways at the end of 12 h of dosing with the DPI (2.41 ± 0.37 μg/g of tissue) was double the amount found after oral dosing (1.25 ± 0.56 μg/g). Lung fibrosis induced in rats using bleomycin was resolved equally well by the two interventions administered q12h for 14 days. We submit that the reduction in systemic exposure to nintedanib and enhanced exposure to target tissue could offer significant therapeutic and safety advantages, and CaHPO4 can be easily developed as an excipient for DPIs.

Alkaline urine is associated with increased risk of calcium phosphate nephrolithiasis in medically complex children receiving enteral nutrition

INTRODUCTION

Calcium phosphate stones are commonly found in medically complex children (MCC) receiving enteral feeds. The objective of this study is to investigate the etiology for calcium phosphate stones in this patient population.

STUDY DESIGN

This is a retrospective cohort study of gastrostomy fed, MCC who presented to a high-volume Pediatric Stone Center from 2015 to 2019. MCC were defined as those with a diagnosis of cerebral palsy and/or severe developmental delay who were non-ambulatory. A control group was composed of newly presenting patients to the stone clinic without comorbid conditions. Twenty-four hour urine collections were performed prior to medical intervention and were compared between MCC and controls.

RESULTS

Twenty-four MCC children were compared to 38 controls. The median age (interquartile range [IQR]) and weight of MCC were 11.9 (7.5, 16.3) years and 28.6 (21.0, 37.0) kg. Urine supersaturation of calcium phosphate (SSCaP) was similar in MCC and controls (1.7 and 2.0, p = 0.40). Weight-based 24-h urine calcium and phosphorus excretion were also similar in MCC and controls. The median BSA-adjusted urine volume was significantly higher in MCC vs controls (2.2 vs. 1.2 L/1.73 m2, p < 0.001), which contributed to lower 24-h average urinary phosphorus (271.9 vs. 689.7 mg/L, p < 0.001) and calcium concentrations (73.3 vs. 132.8 mg/L, p < 0.001). However, urine pH was significantly higher in MCC (7.4 vs. 6.3, p < 0.001), as was net gastrointestinal absorption of alkali (1.1 vs. 0.3 mEq/kg/day, p < 0.001). In regression analysis, SSCaP increased by a factor of 2.82 for every 1-unit increase in urine pH (p < 0.001).

CONCLUSION

A high urine pH is associated with an increased risk of calcium phosphate nephrolithiasis in MCC. This may be caused by a higher alkaline content of enteral feeding formulations compared to children on a standard American diet.

Development and Evaluation of Lactose-Free Single-Unit and Multiple-Unit Preparations of a BCS Class II Drug, Rivaroxaban

Background/Objectives: The aim of the present study was to develop lactose-free formulations of rivaroxaban, a novel oral anticoagulant used for the treatment and prevention of blood clotting. As a BCS Class II drug, rivaroxaban is characterized by poor solubility in aqueous media, posing a significant formulation challenge. Methods: To address this, phosphate-based excipients were employed to prepare both traditional single-unit dosage forms (tablets) and modern multiple-unit pellet systems (MUPS). These formulations were successfully developed and thoroughly evaluated for their physical properties and performance. Results: The resulting formulations demonstrated very good mechanical strength, including appropriate hardness and friability, alongside strong chemical stability. Their dissolution profiles met the requirements of the compendial monograph for Rivaroxaban Tablets and were comparable to those of the reference product, Xarelto® film-coated tablets. Conclusions: This study shows the potential for producing effective, stable, and patient-friendly medications that meet the needs of contemporary society, where an increasing number of individuals suffer from lactose intolerance or seek vegan-friendly alternatives.

The impact of sinkers on coning issues exhibited by tablets in USP2 dissolution apparatus

The objective of this research is to explore the impact of sinkers on the dissolution rate of tablets exhibiting coning in paddle dissolution tests. The ICH M9 guideline refers to the use of sinkers to mitigate coning issues. However, the effectiveness of sinkers on coning phenomena has not been comprehensively investigated. Therefore, this study evaluated whether applying sinkers of different shapes could alleviate coning problems. The dissolution profiles of amlodipine tablet formulations which had been clinically demonstrated to be bioequivalent were assessed in a USP2 Apparatus with and without sinkers. Moreover, the effects of artificially induced coning formed by adding cellulose particles of various sizes on dissolution profiles, and the impacts of sinkers on the dissolution delay caused by the cellulose particles were investigated. Our study suggested that the CLIPS sinker was effective in obtaining in vivo relevant dissolution profiles by facilitating the dispersion of coning. The effect of sinkers varied depending on their shapes and the characteristics of the particles that constituted the coning. These findings enhance our understanding of the effectiveness of sinkers in addressing coning issues and aid in predicting the in vivo dissolution performance of tablet formulations that exhibit coning during dissolution testing.

Taste-Masked Pellets of Warfarin Sodium: Formulation towards the Dose Personalisation

The bitter drug, warfarin, has a narrow therapeutic index (NTI) and is used in paediatrics and geriatrics. The aim of this feasibility study was to formulate the taste-masked warfarin-containing pellets to be applicable for dose personalisation and to improve patient compliance, as well as to investigate the effect of the core type (PharSQ® Spheres M, CELPHERE™ CP-507, and NaCl) on the warfarin release from the Kollicoat® Smartseal taste-masking-coated pellets. The cores were successfully drug-loaded and coated in a fluid-bed coater with a Wurster insert. An increase in particle size and particle size distribution was observed by optical microscopy. In saliva-simulated pH, at the Kollicoat® Smartseal level of 2 mg/cm2, none of the pellets demonstrated drug release, confirming their efficient taste-masking. However, in a stomach-simulated pH, a faster drug release was observed from PharSQ® Spheres M- and CELPHERE™ CP-507-coated pellets in comparison with NaCl cores. Additional experiments allowed us to explain the slower drug release from NaCl-containing pellets because of the salting-out effect. Despite the successful taste masking, the drug release from pellets was relatively slow (not more than 91% per 60 min), allowing for further formulation improvements.

Targeted Clindamycin Delivery Systems: Promising Options for Preventing and Treating Bacterial Infections Using Biomaterials

Targeted therapy represents a real opportunity to improve the health and lives of patients. Developments in this field are confirmed by the fact that the global market for drug carriers was worth nearly $40 million in 2022. For this reason, materials engineering and the development of new drug carrier compositions for targeted therapy has become a key area of research in pharmaceutical drug delivery in recent years. Ceramics, polymers, and metals, as well as composites, are of great interest, as when they are appropriately processed or combined with each other, it is possible to obtain biomaterials for hard tissues, soft tissues, and skin applications. After appropriate modification, these materials can release the drug directly at the site requiring a therapeutic effect. This brief literature review characterizes routes of drug delivery into the body and discusses biomaterials from different groups, options for their modification with clindamycin, an antibiotic used for infections caused by aerobic and anaerobic Gram-positive bacteria, and different methods for the final processing of carriers. Examples of coating materials for skin wound healing, acne therapy, and bone tissue fillers are given. Furthermore, the reasons why the use of antibiotic therapy is crucial for a smooth and successful recovery and the risks of bacterial infections are explained. It was demonstrated that there is no single proven delivery scheme, and that the drug can be successfully released from different carriers depending on the destination.

Improved CaP Nanoparticles for Nucleic Acid and Protein Delivery to Neural Primary Cultures and Stem Cells

Efficiently delivering exogenous materials into primary neurons and neural stem cells (NSCs) has long been a challenge in neurobiology. Existing methods have struggled with complex protocols, unreliable reproducibility, high immunogenicity, and cytotoxicity, causing a huge conundrum and hindering in-depth analyses. Here, we establish a cutting-edge method for transfecting primary neurons and NSCs, named teleofection, by a two-step process to enhance the formation of biocompatible calcium phosphate (CaP) nanoparticles. Teleofection enables both nucleic acid and protein transfection into primary neurons and NSCs, eliminating the need for specialized skills and equipment. It can easily fine-tune transfection efficiency by adjusting the incubation time and nanoparticle quantity, catering to various experimental requirements. Teleofection's versatility allows for the delivery of different cargos into the same cell culture, whether simultaneously or sequentially. This flexibility proves invaluable for long-term studies, enabling the monitoring of neural development and synapse plasticity. Moreover, teleofection ensures the consistent and robust expression of delivered genes, facilitating molecular and biochemical investigations. Teleofection represents a significant advancement in neurobiology, which has promise to transcend the limitations of current gene delivery methods. It offers a user-friendly, cost-effective, and reproducible approach for researchers, potentially revolutionizing our understanding of brain function and development.

Effect of Compaction Pressure on the Enzymatic Activity of Pancreatin in Directly Compressible Formulations

Tableting of biomolecules is a challenging formulation phase due to their sensitivity to various process parameters, such as compression pressure, process dynamics, or the temperature generated. In the present study, pancreatin was employed as a model enzyme mixture, which was formulated in tablet form utilizing the synergistic effects of brittle and plastic excipients (dibasic calcium phosphate and microcrystalline cellulose, respectively). The effect of varying compaction pressure and lubricant concentration on the generated temperature and enzymatic activity was evaluated. The tablets were analyzed for pancreatin content and the activity of two enzymes (protease and amylase) using pharmacopoeial tests. This study indicated that the formulations proposed here allow tableting over a wide range of compaction pressures without adversely affecting pancreatin content and its enzymatic activity.

Towards the Continuous Manufacturing of Liquisolid Tablets Containing Simethicone and Loperamide Hydrochloride with the Use of a Twin-Screw Granulator

Continuous manufacturing is becoming the new technological standard in the pharmaceutical industry. In this work, a twin-screw processor was employed for the continuous production of liquisolid tablets containing either simethicone or a combination of simethicone with loperamide hydrochloride. Both active ingredients present major technological challenges, as simethicone is a liquid, oily substance, and loperamide hydrochloride was used in a very small amount (0.27% w/w). Despite these difficulties, the use of porous tribasic calcium phosphate as a carrier and the adjustment of the settings of the twin-screw processor enabled the optimization of the characteristics of the liquid-loaded powders and made it possible to efficiently produce liquisolid tablets with advantages in physical and functional properties. The application of chemical imaging by means of Raman spectroscopy allowed for the visualization of differences in the distribution of individual components of the formulations. This proved to be a very effective tool for identifying the optimum technology to produce a drug product.

Exploiting synergistic effects of brittle and plastic excipients in directly compressible formulations of Sitagliptin phosphate and Sitagliptin hydrochloride

Direct compression (DC) is the simplest and most economical way to produce pharmaceutical tablets. Ideally, it consists of only two steps: dry blending of a drug substance(s) with excipients followed by compressing the powder mixture into tablets. In this study, immediate-release film-coated tablets containing either Sitagliptin phosphate or Sitagliptin hydrochloride were developed using DC technique.After establishing the optimum ratio of ductile and brittle excipients, five formulations were compressed into tablets using a rotary press and finally film coated. Both powders and tablets were examined by standard pharmacopoeial methods. It has been shown that the simultaneous use of excipients with different physical properties, i.e., ductile microcrystalline cellulose and brittle anhydrous dibasic calcium phosphate, produces a synergistic effect, allowing preparation of Sitagliptin DC tablets with good mechanical strength (tensile strength over 2 N/mm²), rapid disintegration (shorter than 2 min), and fast release of the drug substance (85% of the drug is dissolved within 15 minutes). It was found that the type of calcium phosphate excipient used had a large effect on the properties of the sitagliptin tablets. All formulations developed showed good chemical stability, even when stored under stress conditions (50 °C/80% RH).