Intranasal drug delivery system is a non-invasive drug delivery route with the advantages of no first-pass effect, rapid effect and brain targeting. It is a feasible alternative to drug delivery via injection, and a potential drug delivery route for the central nervous system. However, the nasal physiological environment is complex, and the nasal delivery system requires "integration of medicine and device". Its delivery efficiency is affected by many factors such as the features and formulations of drug, delivery devices and nasal cavity physiology. Some strategies have been designed to improve the solubility, stability, membrane permeability and nasal retention time of drugs. These include the use of prodrugs, adding enzyme inhibitors and absorption enhancers to preparations, and new drug carriers, which can eventually improve the efficiency of intranasal drug delivery. This article reviews recent publications and describes the above mentioned aspects and design strategies for nasal intranasal drug delivery systems to provide insights for the development of intranasal drug delivery systems.
Administration, Intranasal ; Drug Delivery Systems ; Pharmaceutical Preparations ; Drug Carriers ; Brain ; Nasal Cavity/physiology* ; Nasal Mucosa

OBJECTIVETo study the aerodynamics of the normal human nasal cavity under different ambient temperatures.

METHODSBased on CT scanning, a model of a healthy adult's nasal cavity was established using computational fluid dynamics software from Fluent. Airflow in this model was simulated and calculated at ambient temperatures of 0 °C, 24 °C, and 37 °C during periodic breathing.

RESULTSAmbient temperature only had an impact on the temperature in the nasal cavity during the inspiratory phase, and the temperature distribution was not symmetrical in the inspiratory acceleration and deceleration phases. The ambient temperature significantly affected airflow speed in main nasal passages during the inspiratory process, but had little impact on flow status (proportion and streamline of airflow in different nasal passages). Temperature differences increased the irregular air movement within sinuses. The anterior nasal segment, including the area between the valve and the head of the middle turbinate, was the most effective part of the nasal airway in heating the ambient air.

CONCLUSIONSOur findings describe the effects of ambient temperature on airflow parameters in the nasal cavity within a single respiratory cycle. This data is more comprehensively and accurately to determine the relationship between nasal cavity aerodynamics and physiological functions.

Adult ; Air Movements ; Female ; Humans ; Models, Theoretical ; Nasal Cavity ; physiology ; Temperature

OBJECTIVETo compare the characteristics of normal nasal airflow during periodic breathing and steady-state breathing.

METHODSFluent software was used to simulate the nasal cavity and paranasal sinus structures following CT scanning of a normal adult subject. Air flow velocity, pressure, distribution and streamlines were calculated and compared during periodic breathing and steady-state breathing.

RESULTSThe same flux, the performance of nasal airflow on 15.600 s of periodic breathing and steady-state expiratory (entrance flow was 697.25 ml/s) were as follows: air flow in the common and middle meatus accounted for more than 50% and 30% of total nasal cavity flow during two respiratory status. Flow velocity and pressure of nasal cavity and each paranasal sinus were extremely similar. The flow trace during two respiratory status in the inferior and lower part of the common meatus were predominately straight in form.Flow were parabolic in the middle and superior meatus and the middle and upper parts of the common meatus. The flow trace of nasal airflow on 16.495 s of periodic breathing had wide areas vortex in nasopharynx and limen nasi, the average speed was 0.0706 m/s, while the entrance flow 7.62 ml/s stable state of the left nasal expiratory, the average speed was 0.0415 m/s, the flow trace was similar to 697.25 ml/s.

CONCLUSIONThe same flow, except in the junction of the respiratory cycle, the performance of normal nasal airflow during periodic breathing and steady-state breathing were similar.

Adult ; Female ; Humans ; Nasal Cavity ; physiology ; Respiration ; Respiratory Mechanics ; Tomography Scanners, X-Ray Computed

OBJECTIVE: To establish reference values of acoustic rhinometry, rhinomanometry and rhinospirometer in healthy adults in Tianjin area, analyze the effects of age,sex and side on the value, investigate the correlation of the measure values, offer the diagnosis date for test nasal ventilation function in Tianjin area. METHOD: Four hundred and sixty-six healthy adults in Tianjin area were tested. A1 acoustic rhinometry was used to measure the minimum cross-sectional area (MCA), distance of the minimal cross-sectional area to the nostril (DCAN) and the nasal volume from 0-5 cm, 2-5 cm (V5, V2-5); At 150 Pa, 75 Pa and broms, NR6 Rhinomanometry was used to measure unilateral nasal inspiratory resistance (IR)and expiratory resistance (ER), bilateral nasal inspiratory and expiratory resistance (TIR and TER), and differences of the bilateral nasal resistance can be calculated; NV1 Rhinospirometer was used to measure unilateral inspiratory capacity (IC) and expiration capacity (EC), and the nasal partitioning ratio (NPR) can be calculated. Practical measure the distance of nostril to ahead of the inferior turbinate and compare with DCAN. Make the correlational analysis on different index of three exam. RESULT: Reference values of acoustic rhinometry: MCA was (0.45 +/- 0. 16) cm2 for male, (0.44 +/- 0.16) cm2 for female; V2-5 was (3.52 +/- 1.38) cm3 for male, (3.36 +/- 1.22) cm3 for female, V5 was (5.10 +/- 1.47) cm3 for male, (4.86 +/- 1.12) cm3 for female; DCAN have two distance, (2.22 +/- 0.398, 0.53 +/- 0.625) cm was for male, (2.10 +/- 0.37, 0.67 +/- 0.15) cm was for female. No significant gender, side and age differences were shown in MCA, V5, V2-5. Significant gender differences were shown in DCAN but no side and age differences. Reference values of rhinomanometry: Significant gender but no side and age differences were shown in IR, ER, TIR, TER. Reference values of rhinospirometer: IC was (2.06 +/- 1.10) L/20 s for male, (1.37 +/- 0.34) L/20 s for female, EC was (2.15 +/- 1.23) L/20 s for male (1.39 +/- 0.58) L/20 s for female. NPRi was 0.11 [0.05, 0.23],NPRe was 0.11 [0.05, 0.19]. Significant gender but no side and age differences were shown in IC and EC. No gender and age differences were shown in NPRi and NPRe. There was significant correlation found between MCA and IR/ER/IC/EC, IR and IC, ER and EC, Rlr and NPRi/ NPRe. CONCLUSION Acoustic rhinometry,rhinomanometry and rhinospirometer can be useful reference values to evaluate nasal ventilation function, more value will be found if use the three together.
Adolescent ; Adult ; Aged ; China ; Female ; Humans ; Male ; Middle Aged ; Nasal Cavity ; physiology ; Nasal Mucosa ; physiology ; Nose ; physiology ; Reference Values ; Respiration ; Rhinomanometry ; standards ; Rhinometry, Acoustic ; standards ; Young Adult

OBJECTIVETo explore the effect of septoplasty or in combination with out fracture of the inferior turbinate in patients with nasal septum deviation on the airflow field and the nasal airway structure.

METHODSSix patients with nasal septum deviation underwent spiral CT imaging scans before surgery and during the follow-up. The 3D finite element meshes of the nasal airway were developed from the above CT scans. Given three preconditions, the nasal airflow fields were described by the Navier-Stokes and continuity equations at the inspiratory flow rate of 12 L/min. The whole airflow patterns were obtained and then compared with the airflow filed and airway structure changes before and after surgery. SPSS 12.0 software was used to analyze the data.

RESULTSBefore surgery, area of the common airway and the middle and ventral medial regions in the concave side were (1.61 ± 0.18), (0.40 ± 0.10), (0.40 ± 0.14) cm(2) respectively, and those of convex side were (1.30 ± 0.18), (0.33 ± 0.05), (0.36 ± 0.10) cm(2) respectively. The differences between both sides were of no statistical significance (Z value was 1.782, 1.363, 0.526 respectively, all P > 0.05). Airflow of the above airways were (361 ± 68), (131 ± 25), (100 ± 28) ml respectively in concave side and (178 ± 33), (59 ± 26), (59 ± 18) ml respectively in convex side, which differences were significant statistically (Z value were 2.207, 2.201, 2.201 respectively, all P < 0.05). The inferior turbinate in concave side [(0.93 ± 0.10) cm] was statistically (Z = 2.214, P < 0.05) bigger than that in convex side [(0.58 ± 0.12) cm] before surgery. The airflow fields were in disorder in both ill-airways. After surgery, area of the common airway was (2.55 ± 0.44) cm(2) in concave side and (2.20 ± 0.72) cm(2) in convex side respectively, and area of the middle and ventral medial regions in the convex side were (0.58 ± 0.13), (0.81 ± 0.26) cm(2) respectively, which differences were of significance statistically when comparing to areas before surgery (Z value were 2.201, 2.201, 2.201, 2.201, P < 0.05). The airflow passed through nasal airway orderly in both sides. But the thickness of inferior turbinate was (0.73 ± 0.08) cm in concave side after surgery, which difference was significant statistically in comparison to that before surgery (Z = 2.264, P < 0.05). Consequently, nasal resistance decreased from (0.41 ± 0.03) kPa×L(-1)×s(-1) to (0.16 ± 0.01) kPa×L(-1)×s(-1) after surgery, the difference was significantly (Z = -2.207, P = 0.027).

CONCLUSIONSeptoplasty or in combination with out fracture of the inferior turbinate, followed by the self-adaptation consecutively, could improve the airway and breathing capacity of the nose.

Adult ; Air Movements ; Female ; Humans ; Male ; Nasal Cavity ; physiology ; Nasal Obstruction ; surgery ; Nasal Septum ; surgery ; Respiration ; Treatment Outcome ; Turbinates ; surgery ; Young Adult

OBJECTIVE: To investigate the anatomical influence of the hypertrophic inferior turbinate on computational fluid dynamics (CFD) model of unilateral hypertrophic inferior turbinate nasal cavity, and to analyze the bilateral detailed nasal airflow simulations under both inspiratory and expiratory phases in CFD model. METHOD: One male volunteer troubled with unilateral hypertrophic inferior turbinate accepted CT scan. CFD model was built by CT scans through Simplant 10.0 and ANSYS ICEM. Fluent 6.3.26 simulated the airflow of both nasal cavity in breathing rates 200 ml/s. RESULT: 1) In infraturbinal region, the cross-section area (CSA) of the nasal cavity with hypertrophic inferior turbinate was smaller than that in healthy side and the average area difference between two sides was 1.62 cm2. 2) In both inspiration and expiration phases, the hypertrophic infraturbinal produced a markable reduction in intranasal pressures drop along the full length of the infraturbinal region. The volumetric flow rate in the hypertrophic infraturbinal side was 50 ml/s, which equalled to one third of that in healthy side; Mean air speed in the anterior valve region was estimated to be 0.57 m/s at hypertrophic infraturbinal side and 1.83 m/s at healthy side during inspiration; More vortices happened in the hypertrophic infraturbinal side. CONCLUSION The unilateral hypertrophic infraturbinal change the normal anatomy and influence the aerodynamic of nasal cavity, which is harmful to the functions of human nasal in ventilation, temperature accommodation and olfactory sensation.
Adult ; Computer Simulation ; Humans ; Hydrodynamics ; Hypertrophy ; physiopathology ; Male ; Models, Anatomic ; Nasal Cavity ; physiology ; physiopathology ; Nasal Obstruction ; physiopathology ; Tomography, X-Ray Computed ; Turbinates ; physiology ; physiopathology

OBJECTIVESTo investigate the aerodynamics characteristics of nasal cavity in inspiration phase from 60 healthy Chinese people and provide the reference values for future computational fluid dynamics (CFD) research.

METHODSCFD was used for numerical simulation. The indices of main airflow passage, total nasal airway resistance, maximal velocity, maximal wall shear stress, nasal mucosa area, nasal volume and surface area-to-volume ratio were extracted from CFD analysis results. SPSS 16.0 software was used to analyze the data.

RESULTSThe main airflow passage in nasal cavity was common meatus, the mean total nasal airway resistance was (0.211 ± 0.085) kPa·s·L(-1), the mean maximal velocity was (12.01 ± 2.79) m/s, the mean maximal wall shear stress was (2.50 ± 0.89) Pa, the mean nasal mucosa area was (161.2 ± 34.7) mm(2), the mean nasal volume was (31.7 ± 8.1) ml and the mean surface area-to-volume ratio was (0.58 ± 0.09) mm(-1). No significant difference was detected in aerodynamics indices between male and female people.

CONCLUSIONSThe main airflow passage is located in common meatus. The nasal valve area is the key constrictive plane in nasal cavity. There are no gender differences of main airflow characteristics in nasal cavity. The normal ranges of aerodynamics indices could be used for reference values for future CFD research.

Adolescent ; Adult ; Asian Continental Ancestry Group ; Computer Simulation ; Female ; Humans ; Male ; Middle Aged ; Nasal Cavity ; physiology ; Pulmonary Ventilation ; Young Adult

OBJECTIVE: Acoustic rhinometry (AR) was performed to standardize the measurement techniques, result interpretation and reference values of nasal cavity volume (NV) in preschool children. METHOD: (1) Nasal cavity models were used to test the correlations between NV, minimal cross-sectional area (MCA), and nasal resistance. (2) There were 97 four-year-old and 137 five-year-old children underwent AR test. RESULT: (1) Model tests showed that resist the nce were better correlated with the change of volume than the MCA. (2) The average bilateral NV in preschool children was (2.03 +/- 0.4) ml. No significant gender and age difference were observed (P>0.05). CONCLUSION Volume measurement appears more sensitive and reliable than the MCA in assessing nasal patency. The AR result interpretation and normative NV values in preschool children are introduced.
Airway Resistance ; Child, Preschool ; Female ; Humans ; Male ; Nasal Cavity ; anatomy & histology ; physiology ; Reference Values ; Rhinometry, Acoustic ; methods

OBJECTIVE: To obtain the normal values of acoustic rhinometry and rhinomanometry parameters of normal adult and analyze the correlation of two measurement results between rhinomanometry and acoustic rhinometry. METHOD: Eighty-two normal adults were recruited in our research. Acoustic rhinometry was used to acquire unilateral area of first constriction (UA1), unilateral area of second of constriction (UA2), unilateral minimum cross-sectional area (UMCA), unilateral nasal volume 0-5 cm, 2-5 cm (UV5, UV2-5), and rhinomanometer was used to measure the effective unilateral and total nasal resistances in inspiration, expiration at 150 Pa or Broms (radius is 200 Pa) (UR(ins150), UR(ins200), UR(exp150), UR(exp200), TR(ins150), TR(ins200), TR(exp150), TR(exp200)). RESULT: UA1 was (0.63 +/- 0.14) cm2 for male, (0.60 +/- 0.14) cm2 for female; UA2 was (0.72 +/- 0.48) cm2 for male, (0.6 +/- 0.4) cm2 for female; UMCA was (0.50 +/- 0.16) cm2 for male, (0.47 +/- 0.18) cm2 for female; UV5 was (5.68 +/- 1.73) cm3 for male, (5.16 +/- 1.85) cm3 for female; UV2-5 was (4.13 +/- 1.56) cm3 for male, (3.83 +/- 1.66) cm3 for female. No statistical significance was found between men and women (T = 0.093, 0.134, 0.392, 0.408, P > 0.05). UR(ins150) was (0.86 +/- 0.96) Pa/(cm3 x s); UR(ins200) was (0.45 +/- 0.61) Pa/(cm3 x s); UR(exp150) was (0.83 +/- 0.71) Pa/(cm3 x s); UR exp200 was (0.52 +/- 0.88) Pa/(cm3 x s); TR(ins150) was (0.38 +/- 0.34) Pa/(cm3 x s); TR(ins200) was (0.18 +/- 0.24) Pa/ (cm3 x s); TRp(exp150) was (0.38 +/- 0.27) Pa/(cm3 x s); TR(exp200) was (0.19 +/- 0. 24) Pa/(cm3 x s). There was significant correlation between UR(ins150), UR(exp150), TR(ins150), TR(exp150 and UMCA, UV5, UV2 - 5 (P < 0.05, respectively). CONCLUSION There was correlation between acoustic rhinometry and rhinomanometry. The results of this study can be used as a valuable reference to judge nasal cavity condition of normal adult.
Adolescent ; Adult ; Airway Resistance ; Female ; Humans ; Male ; Middle Aged ; Nasal Cavity ; physiology ; Reference Values ; Rhinomanometry ; Rhinometry, Acoustic ; Young Adult

OBJECTIVETo obtain the normal values of four-phase rhinomanometry specific parameters of normal adult Chinese and analyze the correlation between four-phase rhinomanometry and acoustic rhinometry measurement results.

METHODSEighty-five normal adults were recruited. The HRR2 four-phase rhinomanometry was used to acquire the effective resistances in inspiration, expiration and total breathing process (Reffin, Reffex, Refft) and vertex resistance in the process of inspiration and expiration (Vrin and Vrex). The Eccovision acoustic rhinometry was used to measure the minimum cross-sectional area (MCA) and the nasal volume of 0-5 cm nasal cavity (V5).

RESULTSReffin (x(-) +/- s) was (1.28 +/- 1.02) Pa/(cm(3).s) for male, (1.55 +/- 1.03) Pa/(cm(3).s) for female; Reflex (x(-) +/- s) was (1.43 +/- 1.07) Pa/(cm(3).s) for male, (1.75 +/- 1.14) Pa/(cm(3).s) for female; Refft (x(-) +/- s) was (1.34 +/- 0.99) Pa/(cm(3).s) for male, (1.62 +/- 1.03) Pa/(cm(3).s) for female; Vrin (x(-) +/- s) was (1.31 +/- 1.03) Pa/(cm(3).s) for male; (1.60 +/- 1.03) Pa/(cm(3).s) for female, Vrex (x(-) +/- s) was (1.46 +/- 1.04) Pa/(cm(3).s) for male, (1.82 +/- 1.17) Pa/(cm(3).s) for female. No statistically significant difference was found between men and women (r = 0.661, -0.397, 0.127, 0.649, -0.684, P > 0.05, respectively). There was no significant correlation between Reffin, Reflex, Refft, Vrin, Vrex and age, height, weight, head circumference, body surface area, body mass index (P > 0.05, respectively). However, there was significant correlation between Reffin, Reflex, Refft, Vrin, Vrex and MCA, V5 (P < 0.05, respectively).

CONCLUSIONSThe results of four-phase rhinomanometry show significant correlation to acoustic rhinometry.

Adolescent ; Adult ; Airway Resistance ; physiology ; Female ; Humans ; Male ; Middle Aged ; Nasal Cavity ; physiology ; Reference Values ; Respiration ; Rhinomanometry ; methods ; Rhinometry, Acoustic ; methods ; Young Adult