Mechanical, optical, and physicochemical properties of HPMC-based doxazosin mesylate orodispersible films

Abstract In this study, orodispersible films formed from hydroxypropyl methylcellulose (HPMC) E6 (2, 2.5, and 3%) and plasticizers ((glycerin (Gly), propylene glycol (PP), or polyethylene glycol (PEG)), containing doxazosin mesylate, were prepared by the solvent casting method and characterized. Design of experiments (DoE) was used as a statistical tool to facilitate the interpretation of the experimental data and allow the identification of optimal levels of factors for maximum formulation performance. Differential scanning calorimetry (DSC) curves and X-ray powder diffraction (XRPD) diffractograms showed doxazosin mesylate amorphization, probably due to complexation with the polymer (HPMC E6), and the glass transition temperature of the polymer was reduced by adding a plasticizer. Fourier transformed infrared (FTIR) spectroscopy results showed that the chemical structure of doxazosin mesylate was preserved when introduced into the polymer matrix, and the plasticizers, glycerin and PEG, affected the polymer matrix with high intensity. The addition of plasticizers increased the elongation at break and adhesiveness (Gly > PEG > PP), confirming the greater plasticizer effect of Gly observed in DSC and FTIR studies. Greater transparency was observed for the orodispersible films prepared using PP. The addition of citric acid as a pH modifier was fundamental for the release of doxazosin mesylate, and the desirability formulation had a release profile similar to that of the reference product

Optimization and Quest of HPMC loaded Stavudine Controlled Release Dosage Development by Central Composite Design utilizing Reduced Factorial Screening Technique

Abstract The current research focused on screening and finding the significant independent variables in stavudine loaded tablet, followed by optimizing the best formulation using central composite design. The objective of the study to develop stavudine loaded controlled release tablet utilizing reduced factorial design, followed by optimization technique as well as characterization of prepared tablets. Preliminary trial batches were prepared using different grades of hydroxypropyl methylcellulose. The resolution-IV reduced factorial design was selected to screen the significant independent variables in the dosage form design. A total number of eight runs were prepared and responses were recorded. The signified factors identified by half-normal and Pareto chart. The prepared tablets are evaluated for various physiochemical characterizations. Three dependent responses such as hardness, dissolution at 6 hour and 12 hours are considered in optimization process. Later on, drug-polymer interaction study was carried out. The principal of the study design based on finding the best formulation with prefixed set parameter values utilizing the concept of screening technique. It observed that HPMC K15M (57.18 %), HPMC K100 (66.32 %) and PVP K30 (7.97 %) as best composition in a formulation batch would fulfill the predetermined parameter with specific values.

Development of monolithic matrix type transdermal patches containing cinnarizine: Physical characterization and permeation studies

To overcome the problems associated with bioavailability and systemic side effects of the drug by oral administration, monolithic matrix type transdermal patches containing cinnarizine (CNZ) were developed. For this purpose, films based on hydroxypropyl methylcellulose and polyvinylpyrrolidone as matrix-forming polymers were designed. Physical characteristics of transdermal films and drug-excipient compatibility were investigated. Factors affecting in vitro drug release and ex vivo skin penetration and permeation of the drug were studied. It was confirmed that films displayed sufficient flexibility and mechanical strength for application onto the skin for a long time period. Ex vivo penetration experiments gave satisfactory results for transdermal drug delivery through rat skin. The parameters determining good skin penetration were also evaluated. The highest drug permeation rate was obtained with incorporation of Transcutol® (0.102 mg/cm2/h) into the base CNZ formulation, followed by propylene glycol (0.063 mg/cm2/h), menthol (0.045 mg/cm2/h), and glycerin (0.021 mg/cm2/h) as penetration enhancers (p < 0.05). As a result, the developed transdermal patches of CNZ may introduce an alternative treatment for various conditions and diseases such as idiopathic urticarial vasculitis, Ménière's disease, motion sickness, nausea, and vertigo. Thus, the risk of systemic side effects caused by the drug can be reduced or eliminated

Desenvolvimento e caracterização de dispersões sólidas de efavirenz / Development and characterization of efavirenz solid dispersions

A baixa solubilidade aquosa dos insumos farmacêuticos ativos (IFA) é um grande desafio no desenvolvimento de formulações farmacêuticas, pois pode resultar em biodisponibilidade insuficiente e variável. Diversas estratégias de modificação do estado sólido dos compostos ativos, têm sido propostas para incrementar a solubilidade de fármacos pouco solúveis em água. Dentre as estratégias abordadas a ispersão sólida (DS) é uma das formas mais promissoras de aumentar a solubilidade, dissolução e a biodisponibilidade de IFAs com baixa solubilidade aquosa. O efavirenz (EFV) é um inibidor não nucleosídeo da transcriptase reversa (NNRTI) e um dos componentes da terapia antirretroviral de alta atividade (HAART), sendo parte da primeira linha de tratamento de infecções do vírus HIV tipo 1. O antirretroviral está classificado como pertencente à classe II do SCB, e exibe baixa solubilidade aquosa (solubilidade menor que 10 µg/mL) e alta permeabilidade com absorção dependente da taxa de dissolução, resultando em biodisponibilidade oral baixa e variável. A administração de fármacos pouco solúveis na forma de DS é um método atraente para aumentar a biodisponibilidade in vivo. Neste estudo, um método de triagem rápida por evaporação de solvente foi empregado para preparar DS de EFV, variando-se proporções em misturas compostas pelos carreadores, polivinilpirrolidona K-28/32 (PVP K-28/32), copovidona (CoPVP), hidroxipropilmetilcelulose ftalato (HPMCP-50, HPMCP-55 e HPMCP-55s), poloxâmero 188 (P188) e poloxâmero 407 (P407). A solubilidade das DS foi avaliada por meio do método do equilíbrio (shake-flask), onde selecionou-se os polímeros P188 e P407 que conduziram a uma elevada capacidade de saturação em meio aquoso, superior a 1.000 vezes ao fármaco puro. As propriedades físico-químicas e do estado sólido das amostras foram avaliadas por meio de calorimetria exploratória diferencial (DSC); termogravimetria (TG); espectroscopia do infravermelho com transformada de Fourier (FTIR), difratometria de raios X pelo método do pó (DRXP) e ensaios de dissolução com emprego do aparato IV USP. Os resultados de DRXP demonstraram que os carreadores P188 e P407 foram capazes de estabilizar o EFV na forma amorfa nas DS, fato esse evidenciado pela ausência de picos característicos do antirretroviral

he low aqueous solubility of the active pharmaceutical ingredient (API) is a major challenge in the development of pharmaceutical formulations as it may result in insufficient and variable bioavailability. Several strategies for modifying the solid-state of the active compounds have been proposed to increase solubility of drugs that are poorly soluble in water. Among the strategies approaches, solid dispersion (SD) is one of the most promising ways to increase solubility, dissolution and bioavailability of APIs with low aqueous solubility. Efavirenz (EFV) is a non-nucleoside reverse transcriptase inhibitor (NNRTI) and one of the components of highly active antiretroviral therapy (HAART), being part of the first line of treatment of type 1 HIV virus infections. The antiretroviral is classified as belonging to BCS class II, and exhibits low aqueous solubility (solubility less than 10 µg / mL) and high permeability with dissolution ratedependent absorption, resulting in low and variable oral bioavailability. Drug delivery of poorly aqueous soluble drugs in form SD is an appealing method to increase in vivo bioavailability. In this study, a fast screening method of solvent evaporation method was used to prepare EFV SD, varying the proportions in mixtures composed by the carriers polyvinylpyrrolidone K-28/32 (PVP K-28/32), copovidone (CoPVP), hydroxypropylmethylcellulose phthalate (HPMCP-50, HPMCP-55 e HPMCP-55s), poloxamer 188 (P188) e poloxamer 407 (P407). The solubility of the samples was evaluated by the method of equilibrium (shake-flask), wherein the polymers P188 and P407 were selected due to the capacity to promote high saturation in aqueous medium, 1,000 times superior to the pure drug. The physicochemical and solid-state properties of the samples were evaluated by differential scanning calorimetry (DSC); thermogravimetry (TG); Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRPD) and dissolution assays using the IV USP apparatus. The results of XRPD demonstrated that the carriers P188 and P407 were able to stabilize the EFV in amorphous form in the SD, a fact evidenced by the absence of characteristic peaks of the antiretroviral

Establishment of prediction model for personalized water-paste pills based on classification of traditional Chinese medicine materials / 中国中药杂志

The purpose of the present study was to investigate the relationship of the classification of traditional Chinese medicine(TCM) materials with the suitable binder concentration and dosage in the preparation of personalized water-paste pills and establish a model for predicting the binder concentration and dosage. Five representative TCM materials were selected, followed by mixture uniform design. The water-paste pills were prepared by extrusion and spheronization with hypromellose E5(HPMC E5) as the binder. The quality of intermediates and final products was evaluated, and the resulting data were subjected to multivariate statistical analysis. The prediction models for binder concentration and dosage were established as follows: binder concentration: Y_1=0.378 6 + 0.570 1X_A + 2.271 2X_B-0.894 5X_C-0.458 2X_D-1.145 4X_E(when Y_1 < 0, 10% HPMC E5 was required; when Y_1 > 0, 20% HPMC E5 was required), with the accuracy reaching up to 100%; binder dosage: Y_2=32.38 + 0.25X_A + 1.85X_B-0.013X_B~2-0.002 5X_C~2(R~2=0.932 6, P < 0.001). The results showed that the binder concentration and dosage were correlated positively with the proportion of fiber material but negatively with the proportions of sugar material and brittle material. Then the validation experiments were conducted with the prediction models and all the prescriptions could be successfully prepared at one time. These demonstrated that following the classification of TCM materials and the calculation of their proportions in the prescription, the established mathematical model could be adopted for predicting the binder concentration and dosage required in the preparation of personalized water-paste pills, which contributed to reducing the pre-formulation research and guiding the actual production of personalized water-paste pills.

Floating ability and drug release evaluation of gastroretentive microparticles system containing metronidazole obtained by spray drying

Abstract Gastroretentive floating microparticles were developed and evaluated for the controlled metronidazole delivery for treatment of gastric disease. Floating microparticles, varying in proportions of chitosan and hydroxypropyl methylcellulose or ethylcellulose, were obtained by spray drying. Floating microparticles were characterized by physicochemical and in vitro studies, according to their floating ability and drug delivery. Microparticles presented mean diameter from 1.05 to 2.20 µm. The infrared spectroscopy confirmed the drug encapsulation and showed no chemical linkage between microparticles components. X-ray diffraction showed changes in the drug`s solid state, from crystalline to amorphous, indicating partial drug encapsulation, due to the presence of some crystalline peaks of metronidazole in microparticles. All microparticles floated immediately in contact of simulated gastric fluid and both floating and drug release profiles were dependent of microparticles composition. Microparticles samples constituted by chitosan and hydroxypropyl methylcellulose revealed the best relationship between floating duration and drug release, remaining floating during the occurrence of the drug release, ideal condition for the floating gastroretentive systems.

Development and evaluation of bilayer tablets of combination of antibiotics for the treatment of sexually transmitted disease

ABSTRACT The present research work was envisaged to develop bilayer tablets to improve therapeutic efficacy of antibiotic combination for the treatment of sexually transmitted diseases. The combination of two antibiotics i.e. cefixime trihydrate and ofloxacin were used for the preparation of bilayer tablets which act against genito-urinary infections. The formulations comprise of cefixime trihydrate as immediate release layer formulated using different superdisintegrants and ofloxacin as extended release layer containing HPMC K100M. Evaluation of bilayer tablets were performed for the immediate release cefixime layer and sustain release ofloxacin layer with optimization of excipients. The immediate release layer of cefixime showed complete release within 30 min and ofloxacin release was extended up to 24 hours. The similarity factor value of ofloxacin sustained release layer was found to be 87.01 for initial and 80.35 after 3 months stability when compared with marketed reference product. The present study revealed that cefixime trihydrate and ofloxacin bilayer tablets were successfully developed for the use against sexually transmitted infections.

Formulation and optimization of floating matrix tablets of clarithromycin using simplex lattice design

The purpose of the present study was to prepare floating matrix tablets of clarithromycin employing simplex lattice design. Hydroxypropyl methylcellulose [HPMC] and Ethyl Cellulose [EC] were used as matrix forming agents; sodium bicarbonate and citric acid as effervescence producing agents. Simplex lattice design was used as optimization technique employing three independent formulation variables viz. concentration of HPMC [X[1]], Citric Acid [X[2]], EC [X[3]] whereas floating lag time, t[50%], t[90%], and MDT [Mean Dissolution Time] were the response [dependent] variables. Seven formulations [F1-F7] were prepared and evaluated for dissolution studies, floating characteristics, weight variation, hardness, thickness, friability.t[50%] of the formulations was found to be ranging from 317 +/- 2.54 to 522 +/- 2.39 minutes. The t[90%] and MDT of the tablets were found to be ranging between 659.65 +/- 1.89 to 967.35 +/- 1.67 minutes and 527.20 +/- 1.22 to 846.78 +/- 2.61 minutes respectively. Total floating time of the formulations was more than 12 hours and the drug content was in the range of 98.54 +/- 0.46 to 99.92 +/- 0.32. The amount of both HPMC and EC were found to play a dominating role in controlling the release of the drug from the formulation whereas ratios of sodium bicarbonate and citric acid were showing significant effect on the floating lag time. The release exponent [n] from Korsmeyer-Peppas model was found to be between 0.62 and 0.75 indicating non-Fickian or anomalous drug release behavior from the formulated floating matrix tablets. Simplex lattice design was reported to be an effective optimization technique for optimizing pharmaceutical formulations against desired responses

Enteric coated HPMC capsules plugged with 5-FU loaded microsponges: a potential approach for treatment of colon cancer

The work was aimed at developing novel enteric coated HPMC capsules (ECHC) plugged with 5 Florouracil (5-FU) loaded Microsponges in combination with calcium pectinate beads. Modified quasi-emulsion solvent diffusion method was used to formulate microsponges based on 32 factorial design and the effects of independent variables (volume of organic solvent and Eudragit RS100 content) on the dependent variables (Particle size, %EE & % CDR) were determined. The optimized microsponges (F4) were characterized by SEM, PXRD, TGA and were plugged along with calcium pectinate beads in HPMC capsules and the HPMC capsules were further coated with enteric polymer Eudragit L 100 (Ed-L100) and/ or Eudrgit S 100 (Ed-S 100) in different proportions. In vitro release study of ECHC was performed in various release media sequentially SGF for 2 h, followed by SIF for the next 6 h and then in SCF (in the presence and absence of pectinase enzyme for further 16 h). Drug release was retarded on coating with EdS-100 in comparison to blend of EdS-100: EdL-100 coating. The percentage of 5-FU released at the end of 24 h from ECHC 3 was 97.83 ± 0.12% in the presence of pectinase whereas in control study it was 40.08 ± 0.02% drug. The optimized formulation was subjected to in vivo Roentgenographic studies in New Zealand white rabbits to analyze the in vivo behavior of the developed colon targeted capsules. Pharmacokinetic studies in New Zealand white rabbits were conducted to determine the extent of systemic exposure provided by the developed formulation in comparison to 5-FU aqueous solutions. Thus, enteric coated HPMC capsules plugged with 5-FU loaded microsponges and calcium pectinate beads proved to be promising dosage form for colon targeted drug delivery to treat colorectal cancer.

O trabalho teve como objetivo o desenvolvimento de novas cápsulas com revestimento entérico HPMC (ECHC) conectadas com microesponjas carregadas com fluoruracila (5-FU) em combinação com grânuos de pectinato de cálcio. O método de difusão de solvente modificado quasi-emulsão foi usado para formular microesponjas com base no planejamento fatorial 32 e determinaram-se os efeitos das variáveis independentes (volume de solvente orgânico e conteúdo Eudragit RS100) sobre as variáveis dependentes (tamanho de partícula, EE% e % CDR). As microesponjas otimizadas (F4) foram caracterizadas por SEM, PXRD, TGA e ligadas aos grânulos de pectinato de cálcio em cápsulas de HPMC e estas foram, ainda, revestidas com polímero entérico Eudragit L 100 (Ed-L100) e/ou Eudrgit S 100 (Ed S 100) em diferentes proporções. No estudo de liberação in vitro de ECHC foi realizada em vários meios de liberação sequencial SGF durante 2 h, seguido de SIF para as próximas 6 h, e, em seguida, em SCF (na presença e na ausência de enzima pectinase por mais 16 h). A liberação do fármaco foi retardada em revestimento com a EDS-100, em comparação com mistura de EDS-100: EDL-100, de revestimento. O percentual de 5-FU liberado de ECHC 3 ao final de 24 h foi 97,83 ± 0,12% em presença de pectinase, enquanto que para o controle foi de 40,08 ± 0,02% do fármaco. A formulação otimizada foi submetida a estudos Roentgenográficos in vivo, em coelhos brancos Nova Zelândia, para analisar o comportamento das cápsulas desenvolvidas direcionadas ao cólon. Os estudos de farmacocinética em coelhos brancos da Nova Zelândia foram conduzidos para determinar a extensão da exposição sistêmica propiciada pela formulação desenvolvida, em comparação com solução aquosa de 5-FU. Assim, cápsulas entéricas de HPMC revestidas e conectadas com microesponjas carregadas com 5-FU e grânulos de pectinato de cálcio se mostraram promissoras como formulação para liberação do fármaco no cólon no tratamento do câncer colorretal.

Influence of Sodium CMC and HPMC on the Physical Characteristics of Ofloxacin Floating Matrix Tablets.

Aims: Sustained release floating drug delivery systems or gastro retentive drug delivery systems enables prolonged and continuous input of drug to the upper part of gastrointestinal tract and improves the bioavailability of medication. A new strategy is proposed for the development of floating drug delivery systems of Fluoroquinolone antibiotic, Ofloxacin, a potent moiety for treating UTI’s. Methodology: Various rate retarding polymers like HPMC K4M, HPMC 5 cps and swelling agent as Sodium carboxymethyl cellulose in different proportions were tried and optimized to achieve the drug release for 8 hr. All the formulations were evaluated for floating properties, swelling characteristics and in vitro drug release studies. The in vitro drug release was found to be matrix diffusion controlled. Optimized formulation was subjected to intermediate stability studies at various combinations of temperature and humidity according to ICH guidelines. Results: Lower hardness and higher thickness decreased the floating lag time and increased floating duration. Based on drug release studies, formulation F5 was optimized as the best formulation because it released about 89.27 ±2.6% of the drug at the end of 8 hr while other formulations released not more than 80 ±2.2%. This may be due to high NaCMC content which might have caused excessive channeling, thereby giving a burst release. Optimized formulation F5 was found to follow zero order kinetics with r2 value of 0.993. Conclusion: In conclusion we have been proved that HPMC K4M has retarded the drug release, while HPMC 5cps has facilitated high buoyancy time for the tablets. NaCMC has influenced as channeling agent. Formulation F5 was optimized for its long buoyancy time, prolonged duration of drug release, zero order and diffusion controlled drug release kinetics which can assure 100% bioavailability.

Mechanisms of hydroxypropyl methylcellulose for the precipitation inhibitor of supersaturatable self-emulsifying drug delivery systems / 药学学报

Hydroxypropyl methylcellulose (HPMC) propels self-emulsifying drug delivery systems (SEDDS) to achieve the supersaturated state in gastrointestinal tract, which possesses important significance to enhance oral absorption for poorly water-soluble drugs. This study investigated capacities and mechanisms of HPMC with different viscosities (K4M, K15M and K100M) to inhibit drug precipitation of SEDDS in the simulated gastrointestinal tract environment in vitro. The results showed that HPMC inhibited drug precipitation during the dispersion of SEDDS under gastric conditions by inhibiting the formation of crystal nucleus and the growth of crystals. HPMC had evident effects on the rate of SEDDS lipolysis and benefited the distribution of drug molecules across into the aqueous phase and the decrease of drug sediment. The mechanisms were related to the formed network of HPMC and its viscosities and molecular weight. These results offered a reference for selecting appropriate type of HPMC as the precipitation inhibitor of supersaturatable SEDDS.

Alginate/hydrophobic HPMC (60M) particulate systems: new matrix for site-specific and controlled drug delivery

This study aimed to obtain site-specific and controlled drug release particulate systems. Some particulates were prepared using different concentrations of sodium alginate (Na-Alg) alone and others were formulated using different proportions of Na-Alg with hydroxypropyl methylcellulose (HPMC) stearoxy ether (60M viscosity grade), a hydrophobic form of conventional HPMC, using diclofenac potassium (DP) by ion-exchange methods. Beads were characterized by encapsulation efficiency, release profile, swelling, and erosion rate. The suitability of common empirical (zero-order, first-order and Higuchi) and semi-empirical (Ritger-Peppas and Peppas-Sahlin) models was studied to describe the drug release profile. The Weibull model was also studied. Models were tested by non-linear least-square curve fitting. A general purpose mathematical software (MATLAB) was used as an analysis tool. In addition, instead of the widely used linear fitting of log-transformed data, direct fitting was used to avoid any sort of truncation or transformation errors. The release kinetics of the beads indicated a purely relaxation-controlled delivery, referred to as case II transport. Weibull distribution showed a close fit. The release of DP from Na-Alg particulates was complete in 5-6 hours, whereas from Na-Alg hydrophobic HPMC particulate systems, release was sustained up to 10 hours. Hydrophobic HPMC with Na-Alg is an excellent matrix to formulate site-specific and controlled drug release particulate systems.

Este estudo teve como objetivo a obtenção de sistemas particulados para a liberação controlada de fármacos em sítios de ação específicos. Algumas partículas foram preparadas utilizando-se diferentes concentrações de alginato de sódio (Na-Alg) e outras foram formuladas por diferentes proporções de Na-Alg com estearoxílico éter de hidroxipropilmetilcelulose (HPMC) (grau de viscosidade 60M), uma forma hidrofóbica do convencional HPMC, utilizando o diclofenaco de potássio (DP) por métodos de troca iônica. Os grânulos foram caracterizados pela eficiência de encapsulação, perfil de liberação, inchaço e taxa de erosão. A adequação de diferentes modelos empíricos (de ordem zero, primeira ordem e Higuchi) e semi-empíricos (Ritger-Peppas e Peppas-Sahlin) foi estudada para descrever o perfil de liberação do fármaco. O modelo de Weibull também foi estudado. Os modelos foram testados através de ajuste não linear de curva pelo método dos mínimos quadrados. O software matemático MATLAB foi utilizado como ferramenta de análise matemática. Além disso, em vez do método de ajuste linear de dados transformados, foi utilizado o ajuste direto para evitar qualquer tipo de erro de truncamento ou de transformação. A cinética de liberação dos grânulos indicou liberação controlada puramente pelo processo de relaxamento, referida como transporte caso II. A distribuição de Weibull apresentou bom ajuste. A liberação do DP a partir de partículas de Na-Alg foi concluída em 5-6 horas, enquanto que a partir de sistemas particulados de Na-Alg HPMC hidrofóbico, a liberação foi mantida por até 10 horas. O HPMC hidrofóbico com Na-Alg é uma excelente matriz para a formulação de sistemas particulados para a liberação controlada de fármacos em sítios de ação específicos.

Comparison of the characteristics of several polymer materials used in hydrophilic matrix tablets / 药学学报

Pure and drug hydrophilic matrix tablets were prepared by direct compression method with theophylline as a model drug. The characteristics of four hydrophilic matrix polymers, hydroxypropylmethylcellulose (HPMC), polyethylene oxide (PEO), sodium alginate (NaAlg) and xanthan gum (XG), were compared by investigating the water absorption, swelling, erosion and gel layer strength. The sequence of water absorption rate was XG > NaAlg (H) > PEO > NaAlg (L) > HPMC; The sequence of swelling index was XG > PEO > HPMC > NaAlg; The sequence of erosion rate was NaAlg (L) > NaAlg (H) > PEO80 > PEO200 > PEO300 > XG approximately PEO400 approximately K4M > K15M > PEO600 approximately K100M; The sequence of the gel layer strength was PEO > HPMC > XG > NaAlg. For the PEO and HPMC matrix tablets, with the polymer molecular weight increased, the drug release mechanism was gradually transferred from mainly depending on the erosion to the diffusion; for SAL matrix tablets, the drug release mainly depends on erosion mechanism; and for XG matrix tablets, the drug release mainly depends on non-Fick diffusion mechanism. Comparison of the performance difference between the polymer materials will contribute to rational design and prediction of drug release behaviors from matrix tables and ultimately to achieve clinical needs.

Optimization of novel self-microemulsifying mouth dissolving films by response surface methodology / 药学学报

This paper report the development of a new dosage form - self-microemulsifying mouth dissolving films, which can improve the oral bioavailability of water insoluble drugs and have good compliance. A three factor, three-level Box-Behnken design was used for optimizing formulation, investigated the effect of amounts of microcrystalline cellulose, low-substituted hydroxypropyl cellulose and hypromellose on the weight, disintegration time, cumulative release of indomethacin after 2 min, microemulsified particle size and stretchability. Optimized self-microemulsifying mouth dissolving films could fast disintegrate in (17.09 +/- 0.72) s; obtain microemulsified particle size at (28.81 +/- 3.26) nm; and release in vitro at 2 min to (66.18 +/- 1.94)%. Self-microemulsifying mouth dissolving films with broad application prospects have good compliance, strong tensile and can be released rapidly in the mouth through fast self-microemulsifying.

Thermosensitive in situ gel of boanmycin hydrochloride for injection / 药学学报

Poloxamer F127, poloxamer F68 and hydroxypropyl methylcellulose K4M were used to prepare the thermosensitive in situ gel of boanmycin hydrochloride for injection. Its gelation temperature, rheological behavior, texture characteristics, scanning electron microscopy, in vitro and in vivo drug release were evaluated. These results showed that the formulation was a fluid solution at room temperature, which could become semisolid at the temperature of 37 degrees C, and the thermally induced sol-gel transition allowed to be injectable and in situ setting. The formulation was constructed into a tridimensional network at gelation temperature. The drug release was controlled by the diffusion of the drug and the erosion of the gelmatrix. The pharmacokinetics indicated that the drug could be released slowly for up to 48 hours after subcutaneous administration in rats.

Optimization of the formulation of ranolazine hydrochloride sustained-release tablet and its pharmacokinetics in dogs / 药学学报

Ranolazine hydrochloride sustained-release tablet (RH-ST) was prepared and its release behavior in vitro was studied. The pharmacokinetic characteristics and bioavailability in six Beagle dogs after oral administration of RH-ST and ranolazine hydrochloride common tablets (RH-CT) as reference were compared. Three kinds of matrix, hydroxypropylmethylcellulose (HPMC K4M), ethylcellulose (EC 100cp) and acrylic resins (Eudragit RL100) were selected as functional excipients to keep ranolazine hydrochloride (RH) release for 12 hours. Through orthogonal designs, the polymers were quantified and the optimized cumulative release profile was obtained. The single oral dose of RH-ST 500 mg and RH-CT 333.3 mg was given to six dogs using a two way crossover design. Plasma levels were determined by LC-MS and the absorption fractions were calculated according to Loo-Riegelman formula. The steady-state concentration of RH in plasma of six dogs and its pharmacokinetics behaviors after continuous oral administration of RH-ST and RH-CT at different time intervals were studied by LC-MS. The steady-state pharmacokinetic parameters were computed by software program BAPP2.0. With the increase of the amount of the matrix, the drug release was decreased. The most important factor influencing drug release is the quantity of HPMC K4M. Drug release within the period (from 0 h to 12 h) fitted well into Higuchi model. The correlation coefficient (r) between the dissolution in vitro in release media of the distilled water and the absorptin fraction in vivo was 0.9550. To compare with RH-CT, RH-ST in vivo has a steady and slow release behavior, Tmax was obviously delayed (3.00 +/- 0.50) h and the relative bioavailability was over 80 percentage. The combined use of multiple polymers can decrease the tablet weight effectively, and the drug release rate can be decreased both in vitro and in vivo.

Effect of water-soluble polymers on the inhibition of osthole crystallization / 药学学报

This paper is to study the inhibitory effect of water soluble polymers--methyl cellulose (MC), hydroxypropyl methyl cellulose (HPMC), hydroxypropyl cellulose (HPC-M), poloxamer (F68) and polyvidon (PVP) on osthole (OST) crystallization and investigate the impact of polymer concentration and viscosity on crystallization behavior. Also, UV spectrophotometry method was used to determine the drug concentration at different time point to draw the OST concentration-time curve. Results show that HPMC has the most significant inhibition effect on OST crystallization, and drug concentration level is 1.61 times higher than that in control solution within 8 h followed by PVP (1.54) and MC (1.45) respectively. The kinetics of OST recrystallization can be described using first-order reaction, and the crystallization rate constants obtained by analyzing the regression equation indicate that HPMC-60SH-4000 and HPMC-60SH-10000 can greatly influence OST crystal formation. The dissolution rate of drugs precipitated from water-soluble polymer solutions is faster compared with controls in pH 1.2 HCl and pH 6.8 phosphate buffers, which demonstrated that water-soluble polymers can not only change the behavior of drug crystallization but markedly improve the dissolution rate of water insoluble drugs.

In vitro-in vivo correlation study on nimesulide loaded hydroxypropylmethylcellulose microparticles / 药学学报

This study involves mathematical simulation model such as in vitro-in vivo correlation (IVIVC) development for various extended release formulations of nimesulide loaded hydroxypropylmethylcellulose (HPMC) microparticles (M1, M2 and M3 containing 1, 2, and 3 g HPMC, respectively and 1 g drug in each) having variable release characteristics. In vitro dissolution data of these formulations were correlated to their relevant in vivo absorption profiles followed by predictability worth analysis of these Level A IVIVC. Nimaran was used as control formulation to validate developed formulations and their respective models. The regression coefficients of IVIVC plots for M1, M2, M3 and Nimaran were 0.834 9, 0.831 2, 0.927 2 and 0.898 1, respectively. The internal prediction error for all formulations was within limits, i.e., < 10%. A good IVIVC was found for controlled release nimesulide loaded HPMC floating M3 microparticles. In other words, this mathematical simulation model is best fit for biowaiver studies which involves study parameters as those adopted for M3 because the value of its IVIVC regression coefficient is the closest to 1 as compared to M1 and M2.

Studies on preparation of isosorbide-5-mononitrate pulsatile controlled-release pellets and various influence factors / 生物医学工程学杂志

We prepared the isosorbide-5-mononitrate pulsatile controlled-release pellets (PCRP) and studied the influencing factors in vitro. The isosorbide-5-mononitrate (5-ISMN) pellets prepared by extrusion-spheronization technology were coated with swelling material as the inner coating swelling layer, and with ethylcellulose aqueous dispersion as the outer coating controlled layer. The influences of the coating materials of the swelling layer, the coating levels of the swelling layer and controlled layer,and the pH values of the media on the release of 5-ISMN from PCRP were investigated. The drug release from the pellets was pulsatile. The ISMN-5-PCRP, with a lag time of 5 h and more than 80% released within the following 1.5 h,were prepared by using the low-substituted hydroxypropyl cellulose as the inner swelling layer with 15% (weight) in coating thickness, and the ethylcellulose aqueous dispersion as the outer controlling layer with 13% (weight) in coating thickness.

Effects of in vitro conditions on release behavior of different types of sustained and controlled release formulations of breviscapin / 药学学报

Insoluble breviscapin was chosen as the model drug. Bi-layer osmotic pump technology and gel matrix technology were used to prepare the breviscapin sustained and controlled release preparations. Dissimilarity factors (f1) and similarity factors (f2) were applied as similar judgment index to compare the effects of in vitro conditions on the release behavior of different types of breviscapin sustained and controlled release preparations. The tolerance of in vitro release conditions of bi-layer osmotic pump technology and gel matrix technology were studied. The results showed that in vitro release conditions have a greater impact on the gel matrix sustained release formulations, while have almost no effects on the osmotic pump controlled release formulations. Therefore, osmotic pump controlled release technology is less affected by the drug release environment. And it has a very good application prospect.