Drug In Solid Dispersion Research Articles

Formulation for Enhancement of Solubility and Dissolution Rate of Simvastatin using Solid Dispersion

Solid dispersion preliminary solubility analysis was carried out for the selection of the carrier and solid dispersion was prepared with Hydroxy Propyl Methyl Cellulose (HPMC) and Methyl Cellulose (MC). These solid dispersions were analyzed for the solubility and in-vitro dissolution profile solid dispersion of drug with polymer has shown enhanced solubility with improved dissolution rate. Further FTIR, X-Ray studies were carried out. The solubility and dissolution rate of Simvastatin, a drug used for the treatment of hyperlipidaemia. Simvastatin is a selective competitive inhibitor of HMG Co-A reductase. However its absolute bioavailability is 5%. To increase the solubility of drug solid dispersion was prepared. Solid dispersion prepared with polymer in 1:5 ratios shows the presence of amorphous form confirmed by the characterization study. The present investigations showed that solubility of Simvastatin Sodium was markedly increased by its solid dispersion using PVP K30 as carrier. The formulation SDF8 containing (1:8) shows highest dissolution rate. Hence the solid dispersion a way is useful technique in providing fastest onset of action of Simvastatin Sodium as well as enhanced dissolution rate. The study also shows that dissolution rate of Simvastatin can be enhanced to considerable extent by solid dispersion technique with Polymer.

Pre-Processing a Polymer Blend into a Polymer Alloy by KinetiSol Enables Increased Ivacaftor Amorphous Solid Dispersion Drug Loading and Dissolution.

This study compares the effects of pre-processing multiple polymers together to form a single-phase polymer alloy prior to amorphous solid dispersion formulation. KinetiSol compounding was used to pre-process a 1:1 (w/w) ratio of hypromellose acetate succinate and povidone to form a single-phase polymer alloy with unique properties. Ivacaftor amorphous solid dispersions comprising either a polymer, an unprocessed polymer blend, or the polymer alloy were processed by KinetiSol and examined for amorphicity, dissolution performance, physical stability, and molecular interactions. A polymer alloy ivacaftor solid dispersion with a drug loading of 50% w/w was feasible versus 40% for the other compositions. Dissolution in fasted simulated intestinal fluid revealed that the 40% ivacaftor polymer alloy solid dispersion reached a concentration of 595 µg/mL after 6 h, 33% greater than the equivalent polymer blend dispersion. Fourier transform infrared spectroscopy and solid-state nuclear magnetic resonance revealed changes in the ability of the povidone contained in the polymer alloy to hydrogen bond with the ivacaftor phenolic moiety, explaining the differences in the dissolution performance. This work demonstrates that the creation of polymer alloys from polymer blends is a promising technique that provides the ability to tailor properties of a polymer alloy to maximize the drug loading, dissolution performance, and stability of an ASD.

SOLUBILITY ENHANCEMENT OF RIVAROXABAN BY SOLID DISPERSION WITH POLYETHYLENE GLYCOL 4000

Objective: The aim of the work was to enhance the dissolution rate of rivaroxaban by preparing its solid dispersions (SDs) using hydrophilic carrier PEG 4000. Methods: The SDs of rivaroxaban with PEG 4000 were prepared at 1:1, 1:2 and 1:3 w/w ratios by physical mixing, melting and solvent evaporation techniques. The prepared solid dispersions were characterized by Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). Results: Both the solubility and dissolution rate of the drug in these formulations were increased. The used hydrophilic carriers showed a more than two-fold increase in dissolution rate in their prepared solid dispersions by melting or solvent evaporation techniques. The pure drug rivaroxaban as the pure drug shows a dissolution rate of nearly 39 % after 60 m, whereas the solid dispersions by melting or solvent evaporation showed 90% of dissolution after 60 m. The FTIR spectroscopic and DCS thermal studies showed the compatibility of rivaroxaban and the absence of well-defined drug polymer interactions, though the shift in peaks was observed due to the formation of new bonds. Conclusion: Formulation of solid dispersions of drug with hydrophilic carriers is a successful approach for solubility or dissolution rate enhancement of low soluble drug(s). In this work for solubility enhancement of rivaroxaban the hydrophilic carrier PEG 4000 showed significant solubility enhancement.

Solubility Enhancement of Atorvastatin Tablets by Solid Dispersions Using Fenugreek Seed Mucilage

Fenugreek seed mucilage (FSM) is isolated from the seeds of Trigonella Foenum-graecum, commonly known as Fenugreek, which is herbaceous plant. Fenugreek seeds contain high percentage of mucilage, which does not dissolve in water, but swell up and become slick when exposed to fluids. Atorvastatin is one of the HMG-CoA reductase inhibitors (statins), which are lipid-lowering medications used in the primary and secondary prevention of coronary heart disease. Atorvastatin is poorly absorbed orally, its oral bioavailability is very low (about14%) because it is very slightly soluble in distilled water and pH 7.4 phosphate buffer, which would limit its clinical application. The objective of this study is to enhance atorvastatin solubility in order to increase its bioavailability by the formulation of solid dispersion using fenugreek seed mucilage. Mucilage was extracted from the seed and evaluated for flow properties, pH value, FTIR spectroscopy and percentage practical yield. Then solid dispersions with different drug to polymer ratios were prepared from fenugreek mucilage and hydroxy propyl methyl cellulose (HPMC), after that saturation solubility was tested for fenugreek seed mucilage solid dispersion (FSMSD), hydroxxy propyle methyl cellulose solid dispersion (HPMCSD) and pure drug. Tablets were prepared from solid dispersion with the highest saturation solubility, then tablets were tested and evaluated. The tablets showed satisfactory physicochemical properties as 1.77%RSD in tablet weight variation, 1 min disintegration time, 5.24±0.457 Hardness and 89% drug release in 45 min. it is concluded that FSM is a promising excipient that can be used in dosage forms formulation to enhance solubility of low soluble drugs.

Current Techniques of Water Solubility Improvement for Antioxidant Compounds and Their Correlation with Its Activity: Molecular Pharmaceutics.

The aqueous solubility of a drug is important in the oral formulation because the drug can be absorbed from intestinal sites after being dissolved in the gastrointestinal fluid, leading to its bioavailability. Almost 80% of active pharmaceutical ingredients are poorly water-soluble, including antioxidant compounds. This makes antioxidant activity inefficient in preventing disease, particularly for orally administered formulations. Although several investigations have been carried out to improve the solubility of antioxidant compounds, there is still limited research fully discussing the subject. Therefore, this study aimed to provide an overview and discussion of the issues related to the methods that have been used to improve the solubility and activity of antioxidant compounds. Articles were found using the keywords "antioxidant" and "water solubility improvement" in the Scopus, PubMed, and Google Scholar databases. The selected articles were published within the last five years to ensure all information was up-to-date with the same objectives. The most popular methods of the strategies employed were solid dispersion, co-amorphous, and nanoparticle drug delivery systems, which were used to enhance the solubility of antioxidant compounds. These investigations produced impressive results, with a detailed discussion of the mechanism of improvement in the solubility and antioxidant activity of the compounds developed. This review shows that the strategies used to increase the solubility of antioxidant compounds successfully improved their antioxidant activity with enhanced free radical scavenging abilities.

Formulation and Evaluation of Sustained Release Solid Dispersed Nifedipine Microcapsules

Conventional drug delivery system for treating the angina and hypertension are not much effective as the drug do not reach the site of action in appropriate amounts. Thus potent and guarded therapy of this angina and hypertension disorder using specific drug delivery system is a challenging task to the pharmaceutical professionals. The study was aimed at increase the solubility of poorly soluble drug nifedipine and formulating it in sustained release dosage form. Solid dispersion of drug was prepared using Poly vinyl pyrrolidone (PVP) as inert hydrophilic carriers by solvent evaporation technique. A 17-fold increase in dissolution rate of nifedipine was observed with solid dispersion prepared with PVP (K30). Sustained release microcapsules of nifedipine were formulated using Eudragit RS 100 as a polymer, acetone as polymer solvent for Eudragit RS100, N-hexane as a non-solvent, liquid paraffin vehicle, with solid dispersion of nifedipine as core by emulsion solvent evaporation method and modified emulsion solvent evaporation method. Microcapsules from all the batches were found to discrete, spherical and free flowing and % entrapment efficiency was found to be in range of 96.01% to 97.87%. All the batches of microcapsules showed sustained release curve in pH 7.4 phosphate buffer up to 12hours with maximum release up to 97.22% after 12hrs was found to be in B2. SEM studies of the microcapsules showed the surface topography states that prepared microspheres were spherical in shape. Shiny and uniform covered surface with polymer. Keywords: Nifedipine, Poly vinyl pyrrolidone, Solid dispersion, Microcapsules, Emulsion solvent evaporation method

Design of a High Performance Fiber-producing Machine

Abstract The aim of this work is to design a high-productivity, continuously operating fiber producing device utilizing the centrifugal force to yield polymeric nanofibers. The requirements for the design were 1) to provide a capillary-to-collector distance of 50–200 mm that could be adjusted automatically, 2) allow the rotational speed of the spinneret to be changed in the range of 0–25000 1/min and have continuous feeding. The equipment will form the basis of several research topics, such as the creation and study of solid dispersions of drugs, the development of pressure sensors, and the creation of porous filter membranes.

Enhancement of Dissolution profile of poorly water soluble drug using Water Soluble Carriers

Teneligliptin Hydrobromide is a long-acting, orally bioavailable, pyrolidone anti-diabetic activity with a solubility of 1.7mg/ml in water which also depends upon the pH and temperature of the solvent. So, Solid dispersion of drug with different polymers an attempt was made to improve dissolution of teneligliptin hydrobromide. The aim of this study was to prepare, characterize and compare solid dispersions of poorly water soluble anti diabetic drug by using PVP and HPMC for enhancing the dissolution rate of the drug. The solid dispersions were prepared by physical mixing method and kneading method at 1:1, 1:2 and 2:1 ratios of drug to polymer. The drug-excipient interaction study showed that the drug and polymers were compatible with each other. The formulations were evaluated for percent drug content, micromeritics and in-vitro dissolution studies. In the present study it was seen that there was an increase in in-vitro drug release for solid dispersion as compared to the pure drug taken alone. Based on the pattern of drug release, the kneading method showed more drug release as compared to physical mix method. In physical mix method, the rate of dissolution of teneligliptin hydrobromide was increased in teneligliptin and Polyvinylpyrrolidone (PVP) with the proportion of (1:2) when compared to the other formulations. In kneading method, the rate of dissolution of teneligliptin hydrobromide was increased in drug and Hydroxypropylmethylcellulose (HPMC) with the proportion of (1:2) when compared to the other formulations. Finally, solid dispersion containing HPMC, as a carrier, gave faster dissolution rates among all the formulations and was selected as the optimized formulation inthis study.

A Brief Discussion of Multi-Component Organic Solids: Key Emphasis on Co-Crystallization

Co-crystallization (CCs) is a less studied phenomenon related to its applicability and reliability as it is directly related to the generation of newer multicomponent solids like co-crystals (CS), eutectic, salts or solid solutions etc. having improved physicochemical properties compared to their pure components. Further, the design and structural aspects of these multicomponent systems remain hindered compared to other techniques such as nanotechnology or solid dispersion. CC is a newer technique to modify the physicochemical as well as pharmaceutical characteristics of various drugs having issues like solubility, stability, etc. without altering or hindering their pharmacological activities. For drug delivery purpose, CC process has numerous advantages over nanotechnology and solid dispersion drug delivery techniques. CCs can modify the physicochemical properties of active pharmaceutical ingredients (API) have issues like sensitivity toward environmental hazards like temperature, moisture, or photostability issues. The availability of large numbers of conformers makes this technique favorable for the researchers in designing CS of newer and older. Although, solid dispersion and nanotechnology techniques are being utilized to a larger extent still there are some drawbacks of these techniques like stability, toxicological factors and protection from environmental factors need to be considered, while the CCs process drastically modifies the various pharmaceutical parameters without altering the pharmacological properties of API's. Salts, design of CS, their methods of preparation, and their application in various fields with special emphasis on their applicability in the pharmaceutical industry.

Solid Dispersion Preparation by Different Methods to Improve Solubility & Dissolution Simvastatin

The improvement of a pure drug's solubility and dissolution rate in the treatment of hyperlipidemia. Simvastatin is a 5-percent absolute bioavailability selective competitive inhibitor of HMG Co-A reductase. For the selection of the carrier, a preliminary solubility investigation of solid dispersion was performed, and solid dispersion was made using Hydroxy Propyl Methyl Cellulose (HPMC) and gum acacia. Solid dispersion of medication with polymer was created and studied for solubility and in-vitro dissolution profile. Solid dispersion of drug with polymer has shown an increase in solubility and improved dissolution rate. On the obtained formulations, further FTIR, X-Ray, Scanning electron microscopy, and Differential scanning calorimetry experiments were conducted. The existence of amorphous form in a solid dispersion made with polymer in a 1:5 ratio is verified by characterization research. The research also showed that using a solid dispersion approach with Polymer, the dissolving rate of a pure medication may be significantly increased.

The impacts of method selectivity and binders on the properties of carbamazepine granules and their applications: A case study

Background: Carbamazepine (CBZ) is a BCS II class drug, having many challenges in solubility, flowability, and compactibility. The study focused on the improvement of solubility, flow behavior, and drug release of carbamazepine. Methods: Low shear granulation (LSG), extrusion spheronization (ES), high shear granulation (HSG), fluid bed granulation (FBG), and hot melt granulation (HMG) methods were employed to prepare CBZ granules. Polyvinylpyrrolidone (PVP) K29/32, PVP K90, and Hydroxypropyl methylcellulose (HPMC) E5 were used as a binder. The drug to binder ratio was maintained in the proportion of 95:5. The nature of granules was analyzed by using X-ray Diffraction and Differential Scanning Calorimetry techniques. A powder flow tester was utilized to study the flow characteristics of the granules. Results: The HMG has successfully converted the crystalline structure of CBZ granules into an amorphous form. Dispersive and distributive mixing in the HMG has achieved better solid dispersion and fast drug release. The ES technique has reported the incompressible nature of the granules. PVP K90 and HPMC E5 were superior binders for imparting strength to the CBZ granules than PVP K29/32. The FBG has exhibited the free-flowing nature of granules due to their uniform and spherical shape. Conclusion: The HMG and FBG were the most effective methods that have remarkably improved drug release, flow properties, and compactibility of CBZ granules.

Downstream processing of spray-dried ASD with hypromellose acetate succinate – Roller compaction and subsequent compression into high ASD load tablets

Despite wide commercial application of hypromellose acetate succinate (HPMCAS) in spray-dried amorphous solid dispersion (ASD) drug products, little information is available in the references on downstream processing of spray-dried dispersions with HPMCAS. Poor flow and high dilution factor are a challenge in formulating spray-dried ASDs into tablets, leaving little space for other excipients facilitating binding and disintegration. Direct compression is not possible due to the poor powder flow of spray-dried ASDs. Moisture has to be avoided due to the plasticizing properties of water on the ASD, resulting in reduced stability of the amorphous state. Thus, dry granulation by roller compaction and subsequent tablet compression is the preferred downstream process. We report the investigation of downstream processing by roller compaction and tablet compression of a high load formulation with 75% of spray-dried amorphous solid dispersion (Nifedipine:HPMCAS 1:2). A head to head comparison of microcrystalline cellulose/croscarmellose (MCC/cl-NaCMC) as binder/disintegrant vs. MCC and low-substituted hydroxypropyl cellulose (L-HPC) as excipient for binding and disintegration showed improved re-workability of the formulation with MCC/L-HPC after roller compaction. Upon transfer to the rotary press, a 45% higher tensile strength of tablets is observed after dry granulation with MCC/L-HPC.

Solid State NMR Investigation for Molecular States of Specialized Formulation to Improve the Water Solubility of Poorly Water-soluble Drugs

70-90% of recently developed new drug candidates are poorly soluble in water, which creates a series of thorny challenges in developing its oral dosage forms, resulting in low bioavailability. In pre-formulation study, various specialized formulations have been developed to improve drug solubility. Intermolecular interactions between drug and excipients in the formulations can modify the drug state and achieve the improvement of drug solubility. Therefore, the understanding of intermolecular interaction is essential to design formulations with higher quality and to assure the quality as a pharmaceutical product. Solid-state NMR has attracted much attention as a promising method to evaluate the molecular state of a drug and the interaction between a drug and excipient in its formulation. I have applied solid-state NMR and its characteristic technique, namely magic-angle spinning (MAS), for various specialized formulations including amorphous solid dispersion, supersaturated solution, drug-loaded organic nanotube, and drug nanosuspension. The intermolecular interactions of drug and excipient in amorphous solid dispersion have been identified by 13C and 15N solid-state NMR. High-resolution MAS determined the interaction modes of drug and excipient in a supersaturated solution. The two-step dissolution profile of drug from organic nanotube was understood, based on the molecular states revealed by the combination of various solid-state NMR techniques. A suspended-state NMR clarified the nanostructure of drug nanoparticles dispersed in water. It is expected that more qualified pharmaceutical formulations with improved drug solubility can be designed based on the remarkable development of recent solid-state NMR technology.

A Comparative Study of Selected Drug Delivery Systems: Key Emphasis on Cocrystallization

:The low solubility of an active pharmaceutical ingredient particularly biopharmaceutics classification system (BCS) Class II drugs leads to a lower dissolution profile, which in result causes a reduction in the overall bioavailability of drugs. Numerous approaches like nanotechnology, solid dispersion technique, micronization techniques, etc were aimed by scientists in the past to resolve this issue, but still not enough to get the desired outcomes.:Key focus of this review is the study of the advantages and disadvantages of cocrystallization, nanotechnology and solid dispersions drug delivery techniques and the benefits of using cocrystallization techniques over the above-mentioned techniques.:Various parameters including pharmaceutical, pharmacological and toxicological effects related to these mentioned drug delivery systems have been compared. Their advantages and disadvantages have been elaborated.:For drug delivery purpose, the cocrystallization process has numerous advantages over nanotechnology and solid dispersions drug delivery techniques discussed in the text. Cocrystallization is a newer technique that can modify the physicochemical and pharmaceutical properties of active pharmaceutical ingredients (API) with low solubility, low stability or sensitivity toward environmental hazards like temperature, moisture or photostability issues. During cocrystallization, the drug and the coformer interact with each other non-covalently in a fixed stoichiometric ratio. The availability of a large number of coformers makes this technique to be favorable for the researchers in designing cocrystals of newer and older API’s.:Although solid dispersions and nanotechnology techniques are being utilized to a larger extent, still there are some drawbacks of these techniques like stability, toxicological factors and protection from environmental factors that need to be considered, while the cocrystallization process drastically modifies the various pharmaceutical parameters without altering the pharmacological properties of API’s. Here in this review, we performed a comparative analysis between nanotechnology, solid dispersion and cocrystallization techniques along with the importance of cocrystallization in the modification of drug profile and various applications in the pharmaceutical and allied industry.

Enhancement of Solubility and Dissolution Rate of Atorvastatin Using Solid Dispersion

The solubility and dissolution rate of Atorvastatin, a drug used for the treatment of hyperlipidaemia. Atorvastatin is a selective competitive inhibitor of HMG Co A reductase. However, its absolute bioavailability is 5%. To increase the solubility of drug solid dispersion was prepared. Solid dispersion preliminary solubility analysis was carried out for the selection of the carrier and solid dispersion was prepared with Hydroxy Propyl Methyl Cellulose (HPMC) and Methyl Cellulose (MC). These solid dispersions were analyzed for the solubility and in-vitro dissolution profile solid dispersion of drug with polymer has shown enhanced solubility with improved dissolution rate. Further FTIR, X-Ray studies were carried out. Solid dispersion prepared with polymer in 1:5 ratios show the presence of amorphous form confirmed by the characterization study. The present investigations showed that solubility of Atorvastatin Sodium was markedly increased by its solid dispersion using PVP K30 as carrier. The formulation SDF8 containing (1:8) shows highest dissolution rate. Hence the solid dispersion a way is useful technique in providing fastest onset of action of Atorvastatin sodium as well as enhanced dissolution rate. The study also shows that dissolution rate of Atorvastatin can be enhanced to considerable extent by solid dispersion technique with Polymer.

Enhancement of Solubility and Dissolution rate of Pravastatin using solid Dispersion

The solubility and dissolution rate of pravastatin, a drug used for the treatment of hyperlipidaemia. Pravastatin is a selective competitive inhibitor of HMG Co A reductase. However its absolute bioavailability is 5%. To increase the solubility of drug solid dispersion was prepared. Solid dispersion preliminary solubility analysis was carried out for the selection of the carrier and solid dispersion was prepared with Hydroxy Propyl Methyl Cellulose (HPMC) and Methyl Cellulose (MC). These solid dispersions were analyzed for the solubility and in-vitro dissolution profile solid dispersion of drug with polymer has shown enhanced solubility with improved dissolution rate. Further FTIR, X-Ray studies were carried out. Solid dispersion prepared with polymer in 1:5 ratios shows the presence of amorphous form confirmed by the characterization study. The present investigations showed that solubility of Pravastatin sodium was markedly increased by its solid dispersion using PVP K30 as carrier. The formulation SDF8 containing (1:8) shows highest dissolution rate. Hence the solid dispersion a way is useful technique in providing fastest onset of action of Pravastatin sodium as well as enhanced dissolution rate. The study also shows that dissolution rate of pravastatin can be enhanced to considerable extent by solid dispersion technique with Polymer.

Microwave induced in situ amorphisation facilitated by crystalline hydrates

Amorphisation within the final dosage form, i.e. in situ amorphisation, seeks to circumvent the potential stability issues associated with poorly soluble drugs in amorphous solid dispersions (ASDs). Microwave irradiation has previously been shown to enable in situ preparation of ASDs, when a high amount of microwave absorbing water was introduced into the final dosage form by conditioning at high relative humidity. In this study, an alternative to this conditioning step was investigated by introducing crystal water in form of sodium dihydrogen phosphate (NaH2PO4) di-, and monohydrate, in compacts prepared with 30 % w/w celecoxib (CCX) in polyvinylpyrrolidone K12 (PVP). As controls, compacts prepared with NaH2PO4 anhydrate and without NaH2PO4 were included in the study. The quantification of amorphous CCX after microwave irradiation showed an increase in CCX amorphicity for compacts containing NaH2PO4 di-, and monohydrate with increasing irradiation time. Complete amorphisation of CCX in compacts containing NaH2PO4 di-, and monohydrate was observed after 6 min, while no appreciable amorphisation was observed for the control compacts containing NaH2PO4 anhydrate and without NaH2PO4. Modulated differential scanning calorimetric analysis revealed that a homogenous ASD was formed after 12 min and 6 min for compacts containing NaH2PO4 di-, and monohydrate, respectively. Thermal gravimetric analysis indicated that NaH2PO4 monohydrate showed higher dehydration rates compared to the dihydrate, which in turn resulted in higher compact temperatures, and overall increased the rate of amorphisation and reduced the microwave irradiation time necessary to achieve a homogenous ASD. The present results confirmed the suitability of NaH2PO4 di- and monohydrate as alternative sources of water, the primary microwave absorbing material, for in situ microwave amorphisation. The use of crystalline hydrates as water reservoirs for in situ amorphisation circumvents the time-consuming and highly impractical conditioning step previously reported in order to achieve complete amorphisation. Additionally, it allows for easier and more accurate adjustment of the compacts water content, which directly affects the temperature reached during microwave irradiation, and thus, the rate of amorphisation.

Facile preparation of solid dispersions by dissolving drugs in N-vinyl-2-pyrrolidone and photopolymerization

Drug solid dispersions improve the dissolution of drugs in aqueous media for enhancement of oral bioavailability. The current preparation methods of drug solid dispersions mainly involve the evaporation of solvents or the melting of drugs and matrix. Here, we create a new and simple method for the preparation of drug solid dispersions by dissolving drugs in N-vinyl-2-pyrrolidone (NVP) and then NVP photopolymerization. A variety of drugs were explored to find whether they were suitable for this method and only some of them were soluble in NVP and formed transparent and hard solid dispersions, including fluconazole, ketoconazole, bifonazole, miconazole nitrate, sulfamethoxazole, aspirin, ibuprofen and artesunate. The formation of photocuring solid dispersions was highly related to the free radical scavenging function of drugs. Those drugs with strong free radical scavenging capability, including curcumin, resveratrol, quercetin, genistein, puerarin, nicergoline, olanzapine, indomethacin, did not form solid dispersions. They scavenged 2,2-diphenyl-1-picrylhydrazyl free radicals, which was demonstrated by ultraviolet spectrometry and electron spin resonance. The scavenging of free radicals stopped the chain polymerization of NVP. The Fourier transform infrared spectra, X-ray diffraction and differential scanning calorimetry of ibuprofen solid dispersions and artesunate solid dispersions showed the molecularly miscible state of the drugs and the hydrogen bonding between the drugs and polyvinyl pyrrolidone. The NVP-based solid dispersions of the two drugs had faster and more complete dissolution than their traditional solid dispersions. The NVP photopolymerization-based solid dispersion method provides a new choice for the production of solid dispersions in the research and industrial fields.

Recent trends of self-emulsifying drug delivery system for enhancing the oral bioavailability of poorly water-soluble drugs

The oral route is the most popular route for the clinical administration of drugs to treat various diseases. Before a drug is absorbed into the blood circulation, it must undergo dissolution and permeation. However, most drugs exhibit poor aqueous solubility, and their limited absorption leads to low oral bioavailability. The solubility of hydrophobic drugs can be improved by various ways, such as solid dispersion, salt formation, pH modification, and self-emulsifying drug delivery system (SEDDS) use. Among them, the SEDDS has garnered attention during recent years as it improves oral bioavailability, reduces drug dose, and increases drug protection from unsuitable environment in the gastrointestinal tract. SEDDS comprises lipid-based formulations. It can solve the problems related to the dissolution and bioavailability of the Biopharmaceutics Classification System Class II and IV drugs. Depending on the preparation procedure, drug-loaded SEDDS can be divided into micro- (SMEDDS) and nano- (SNEDDS) formulations. In this review, we summarize the classification system of lipid formulations, the mechanism underlying improved oral drug absorption by SEDDS, and recent advances in the SEDDS. The SEDDS is a potential formulation for drug delivery. Owing to its small particle size, large surface area, high encapsulation efficiency, and high drug loading, the SEDDS can improve the rate and extent of oral absorption by maximizing drug solubility in the intestinal absorption site. Moreover, because of the lipid-based formulation of SEDDS, it can stimulate and enhance lymphatic transport of drugs to avoid hepatic first-pass metabolism, and thus improve their bioavailability.

Thermal Stability of Amorphous Solid Dispersions.

Amorphous solid dispersion drug delivery systems (ASD DDS) were proved to be efficient for the enhancement of solubility and bioavailability of poorly water-soluble drugs. One of the major keys for successful preparation of ASD is the selection of appropriate excipients, mostly polymers, which have a crucial role in improving drug solubility and its physical stability. Even though, excipients should be chemically inert, there is some evidence that polymers can affect the thermal stability of active pharmaceutical ingredients (API). The thermal stability of a drug is closely related to the shelf-life of pharmaceutical products and therefore it is a matter of high pharmaceutical relevance. An overview of thermal stability of amorphous solids is provided in this paper. Evaluation of thermal stability of amorphous solid dispersion is perceived from the physicochemical perspective, from a kinetic (motions) and thermodynamic (energy) point of view, focusing on activation energy and fragility, as well all other relevant parameters for ASD design, with a glance on computational kinetic analysis of solid-state decomposition.